Julia L. Stevens

In Vivo Behavior of Peptide-Specific T Cells During Mucosal Tolerance Induction: Antigen Introduced Through the Mucosa of the Conjunctiva Elicits Prolonged Antigen-Specific T Cell Priming Followed by Anergy

The mucosa of the conjunctiva is an important site of entry for environmental Ags as well as Ags emanating from the eye itself. However, very little is known about T cell recognition of Ag introduced through this important mucosal site. We have characterized the in vivo process of CD4 T cell recognition of Ag delivered via the conjunctival mucosa. Application of soluble OVA to the conjunctiva of BALB/c mice induced potent T cell tolerance. APC-presenting OVA peptide in vivo was only found in the submandibular lymph node and not in other lymph nodes, spleen, or nasal-associated lymphoid tissue. Similarly, in TCR transgenic DO11.10 adoptive transfer mice, OVA-specific CD4+ T cell clonal expansion was only observed in the submandibular lymph node following conjunctival application of peptide. These experiments thus define a highly specific lymphatic drainage pathway from the conjunctiva. OVA-specific T cell clonal expansion peaked at day 3 following initiation of daily OVA administration and gradually declined during the 10-day treatment period, but remained elevated compared with nontreated adoptive transfer mice. During this period, the T cells expressed activation markers, and proliferated and secreted IL-2 in vitro in response to OVA stimulation. In contrast, these cells were unable to clonally expand in vivo, or proliferate in vitro following a subsequent OVA/CFA immunization. These results suggest that Ag applied to a mucosal site can be efficiently presented in a local draining lymph node, resulting in initial T cell priming and clonal expansion, followed by T cell anergy.

Pseudotumor of the orbit in early childhood

Orbital pseudotumor, also known as idiopathic orbital inflammation, is defined as a nonspecific, nonneoplastic inflammatory process of the orbit without identifiable local or systemic causes. The disorder, first described by Birch-Hirschfield in 1905, is more prevalent in the adult population than in the pediatric population. In our study we discuss two cases of pseudotumor of the orbit in children less than 18 months old. This report will highlight the evaluation and management of pediatric orbital pseudotumor and the importance of its inclusion in the differential diagnosis of orbital disorders in young children.

Fusiform P1 Segment Artery Aneurysm in a Pediatric Patient: Technical Case Report

We present an unusual aneurysm in a pediatric patient. Due to the fusiform nature of the aneurysm and the small size of the patient, a unique surgical solution was applied. One year of clinical follow-up is also provided.

Dichoptic luminance beat visual evoked potentials in the assessment of binocularity in children.

Direct evidence of a distinct cortical binocular pathway has been provided by the production of nonlinear (difference) beats from dichoptic luminance stimulation in stereonormal adults and the absence or diminution of these beats in stereoblind subjects. We have investigated a clinically useful application of this technique in a pediatric population with potentially abnormal binocular vision. We recorded dichoptic luminance beat visual evoked potentials (VEPs) from 20 children (ages 7 months to 8 years) with abnormal binocular ability secondary to strabismus and/or amblyopia and compared this to a control group of 20 children with normal binocularity. Stereoblind children generated significantly lower dichoptic signal-to-noise ratios than stereonormal children (P < .001). Responses to monoptic multifrequency flicker were not significantly different between the two groups (P = .936). This dichoptic VEP can be performed quickly and easily on young children and gives a quantitative assessment of cortical binocularity that may not be determinable by standard clinical methods. This technique may also prove useful for the preoperative gradation of binocular potential and prediction of postoperative binocular fusion.

Transgenic expression of IFN-gamma in the murine lens results in multiple ocular abnormalities and an early but self-limited inflammatory response.

The anterior chamber of the eye is known to be an immune privileged site, due to both local and systemic effects on the immune response. Injection of IFN-gamma into the anterior chamber (AC) overcomes the suppression of antigen-specific delayed hypersensitivity responses normally seen in the eye. Transgenic mice expressing increased IFN-gamma in the lens under the alpha A-crystallin promoter were produced to determine whether the proinflammatory effects of IFN-gamma would abolish immune privilege and promote loss of tolerance as has been seen in non-immune privileged tissues. Two alpha C/IFN-gamma transgenic lines are described which demonstrate multiple ocular and lenticular abnormalities some of which are developmental in origin and others that may be secondary to the inflammatory effects of IFN-gamma. A significant inflammatory cell infiltrate which is observed in the AC and vitreous from birth to 4 weeks of age, consists initially of macrophage and polymorphonuclear leukocytes and then CD4+ T lymphocytes. However, the infiltrate is essentially resolved by 6 weeks of age. Therefore, although lens-specific expression of IFN-gamma results in early loss of immune privilege, chronic uveitis does not occur probably due to the lack of continued IFN-gamma expression.

Marion L. ‘Jack’ Walker

Accessible online at: http://BioMedNet.com/karger The most important and difficult job for Pediatric Neurosurgery is that of the Managing Editor. With Donald Reigel’s retirement after 14 years, the journal was left with a void in this essential position. Donald Reigel and I met and then recommended to the President of the American Society of Pediatric Neurosurgeons that he appoint Marion ‘Jack’ Walker as the new Managing Editor. Gordon McComb agreed and asked him to take the job. After some thought and discussion with his associates and office staff, Jack has accepted. Amazingly, literally within days, Jack transferred the entire management to Salt Lake City and the journal never missed a beat. We are indeed fortunate that Jack Walker stepped forward and accepted this position. It requires a great deal of his time, and his secretary’s time which is not funded by the journal. Throughout his career, Jack has been committed to the development of pediatric neurosurgery. He founded the pediatric neurosurgery service of the University of Utah and is director of an outstanding fellowship program. He has supported the editorial staff and was the head of the neurosurgery section. Jack is a frequent contributor to the journal. Jack Walker has served as president of the American Society of Pediatric Neurosurgeons, is the Chairman of the Pediatric Section of the American Association of Neurological Surgeons, the Chairman of the American Board of Pediatric Neurological Surgery and on the Executive Committee of the International Society for Pediatric Neurosurgery. He is a much sought after speaker nationally and internationally. Jack is also involved in the effort to assist in the development of pediatric neurosurgery in Honduras. On behalf of the staff of Pediatric Neurosurgery, I thank Jack Walker for accepting and welcome him as the new Managing Editor.