Effect of electrical stimulation on middle latency response in the guinea pig

A temporary threshold shift (TTS) has been demonstrated in the electrically evoked middle latency response (EMLR) following exposure to moderate levels of continuous electrical stimulation via a cochlear implant. The threshold at which the EMLR was elicited in chronically implanted guinea pigs was elevated by approximately 100% following 30 minutes of moderate intensity (200 microA or more) sinusoidal electrical stimulation of the cochlea. Results obtained under anesthesia varied unacceptably. In awake animals, EMLR thresholds were stable over time and consistent TTSs were observed. The threshold returned to prestimulation levels within 4 hours following termination of the stimulation. The possibility of histopathologic changes and the relevance of these findings in setting safe output levels for cochlear implant processors are discussed.     

Langerhans cell histiocytosis after therapy for a malignant germ cell tumor of the central nervous system

Langerhans cell histiocytosis (LCH) is a clonal neoplastic disorder that results in a spectrum of clinical manifestations. Known to be associated with a variety of malignant diseases, LCH may precede, coincide with, or develop after the diagnosis of cancer. A child with a malignant germ cell tumor of the brain who subsequently experienced LCH is reported. The 8-year-old boy was treated for an immature teratoma of the posterior fossa with gross total resection and craniospinal irradiation preceding bleomycin, etoposide, and vinblastine chemotherapy for four cycles. Seven months after completion of therapy, he experienced multifocal bone disease with LCH.     

Transfusion management strategies: a survey of practicing pediatric hematology/oncology specialists

BACKGROUND: Little is known about the criteria used by pediatric oncologists for the transfusion of red blood cells and platelets to pediatric oncology patients. PROCEDURE: Data regarding red blood cell and platelet transfusion practices were collected with an internet-based survey of physician members of the American Society for Pediatric Hematology/Oncology (ASPH/O). Respondents were asked to define platelet and red blood cell transfusion thresholds in a variety of clinical scenarios, and to describe criteria for dealing with cytomegalovirus (CMV) transmission from blood products, platelet dosing strategies, and prevention of RhD alloimmunization. RESULTS: The overall response rate was 31.4% (264 of 841). Of the respondents, 76% indicated that their institution had defined criteria for acceptable transfusion practice; of these respondents, 114 (57%) indicated that there were special guidelines for pediatric oncology patients. Examination of the distribution of threshold platelet counts and hemoglobin levels that would prompt transfusion indicated a wide range of transfusion practice in commonly encountered clinical scenarios. Similar variability in practice was evident in platelet dosing strategies, CMV prevention strategies, and in the use of anti-D in RhD-negative patients who received RhD-positive platelets. CONCLUSIONS: This current survey demonstrates that transfusion practices vary widely among pediatric hematology/oncology specialists and that prospective clinical trials may be necessary to determine optimal criteria for blood product support in pediatric oncology patients.     

The pediatrician's role in the prevention of missing children

In 2002, the Second National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children report was released by the US Department of Justice, providing new data on a problem that our nation continues to face. This clinical report describes the categories of missing children, the prevalence of each, and prevention strategies that primary care pediatricians can share with parents to increase awareness and education about the safety of their children.