NCCN pediatric neuroblastoma practice guidelines. The National Comprehensive Cancer Network.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to V Castle.
Explore the source record for details and available documents.
Multiple-organ infiltration by mature, benign erythrophagocytic histiocytes is the pathologic hallmark of the virus-associated hemophagocytic syndrome (VAHS). Although VAHS has been described in a number of clinical settings, it has been reported following bone marrow transplantation (BMT) only once previously. Our report identifies the clinical and laboratory features associated with VAHS and compares the immune defects described in VAHS with those known to occur following BMT.
Thrombospondin (TSP) is a trimeric glycoprotein which is synthesized and incorporated into the extracellular matrix by a wide variety of cells. TSP is involved in a number of cellular processes which govern tumor cell behavior including mitogenesis, attachment, migration, and differentiation. To directly assess the role of TSP in tumor cell growth and spread, a human squamous carcinoma cell line, with high TSP production and an invasive phenotype, was transfected with a TSP cDNA antisense expression vector. Five unique transfected clones were obtained with reduced TSP production. Expression of the transfected antisense sequence in these clones was verified by a ribonuclease protection assay. These clones demonstrated reduced growth rates in vitro when compared with a vector transfected control. After subcutaneous inoculation into athymic mice, the antisense clones formed either no tumors or tumors that were slow growing and highly differentiated. This contrasted with the vector-transfected clone which produced poorly differentiated, rapidly growing, invasive tumors. Our results argue in favor of a direct role for TSP in determining the malignant phenotype of certain human tumors.
The present authors developed a modified template bleeding time for use in the newborn infant. The sensitivity of the bleeding time to the presence of antibiotics, indomethacin, generalized illness, and thrombocytopenia was tested in 242 infants. Both indomethacin and thrombocytopenia similarly prolonged the BT, and the latter could be corrected by raising the platelet count.
Thrombocytopenia occurs frequently in sick neonates that have experienced perinatal asphyxia. This study investigated the effect of one component of asphyxia, hypoxia, on platelet lifespan and site of sequestration. 111Indium oxine platelet survivals with scintigraphic imaging were performed in newborn and adult rabbits exposed to room air (normoxia) or following exposure to a 15 minute, severe hypoxic insult (FIO2 = 0.05). Platelet survivals in normoxic adults (n = 27) and newborn rabbits (n = 11) were similar (60 +/- 3.9 hr vs 64 +/- 8.0 hr, m +/- SEM). Inhalation of 5% oxygen for 15 minutes was not associated with an acidemia and did not produce thrombocytopenia but significantly shortened the platelet survival to 34 +/- 3 hr in the adult (n = 18) and 38 +/- 3 hr in the newborn rabbit (n = 7). Postmortem measurement of the sites of 111In-platelet accumulation showed that under normoxic conditions the platelets accumulated in the liver and spleen (23 +/- 4.3% and 8 +/- 1.0% of the total body counts) in the adult with even greater accumulation in the liver (58 +/- 6.8%) and spleen (19 +/- 4.9%) of the newborn (p less than 0.001). The latter observation was likely due to the relatively increased size of the liver and spleen in the newborn compared to the adult. Hypoxia did not alter the site of platelet sequestration in adults or newborns. Our results suggest that the newborn has the same platelet survival as the adult and that acute, severe hypoxia significantly shortens the survival of platelets in both groups. Although the sites of sequestration are qualitatively the same in the newborn, there is greater sequestration in the liver and spleen when compared to the adult.
This study was designed to determine the postnatal development of the human coagulation system in the healthy premature infant. Consecutive mothers of healthy premature infants born at either St Joseph's Hospital or McMaster University Medical Centre in Hamilton were asked for consent. One hundred thirty-seven premature infants (30 to 36 weeks of gestational age) entered the study. The premature infants did not have any major health problems and did not require ventilation or supplemental oxygen. Demographic information and a 20-mL blood sample were obtained in the postnatal period on days 1, 5, 30, 90, and 180. Between 40 and 96 premature infants were studied on each day for each of the following tests: prothrombin time, activated partial thromboplastin time, thrombin clotting time, plasminogen; 13 factor assays [fibrinogen, II, V, VII, VIII, IX, X, XI, XII, XIII, high-mol-wt kininogen (HMWK), prekallikrein (PK), von Willebrand factor (vWF)] and eight inhibitors [antithrombin III (AT-III), heparin cofactor II, alpha 2-antiplasmin, alpha 2-macroglobulin, alpha 1-antitrypsin, C1 esterase inhibitor, protein C (PC), and protein S (PS)]. A combination of biologic and immunologic assays were used. Between 30 to 36 weeks there was a minimal effect of gestational age for levels of AT-III, PC, and factors II and X only; therefore, the entire data set was used to generate reference ranges for these components of the coagulation system for premature infants. Next, the results for the premature infants were compared with those of a previously published study in 118 fullterm infants and with those for adults. An effect of gestational age was shown for plasminogen, fibrinogen, factors II, V, VIII, IX, XI, XII, HMWK, and all eight inhibitors. In general, the postnatal maturation towards adult levels was accelerated in premature infants as compared with the fullterm infants. By 6 months of age, most components of the coagulation system in premature infants had achieved near adult values.
In a 1-year prospective study, the outcome in infants with a platelet count less than 100 X 10(9)/L (n = 97) was compared with the outcome in an age-, weight-, and disease-matched nonthrombocytopenic control group (n = 80). The hemostatic impact of the thrombocytopenia was assessed by modified template bleeding time, hemorrhage score, and determination of the presence and extent of intraventricular hemorrhage (IVH) in thrombocytopenic infants weighing less than 1500 at birth (n = 39) compared with all nonthrombocytopenic infants less than 1500 g (n = 122) admitted during the study period. The development outcome in infants less than 1500 g was compared at 12 months after delivery. Neonatal thrombocytopenia had a major impact on hemostatic integrity: bleeding time was inversely related to platelet count (r = -0.56, P less than 0.001) and became prolonged when the platelet count fell to less than 100 X 10(9)/L. In addition, many infants (40%) had evidence of platelet dysfunction with prolonged bleeding times despite only moderately reduced platelet counts (75 to 150 X 10(9)/L). The hemorrhage score was greater in the thrombocytopenic infants compared with the sick control infants, and increased as the platelet count fell (r = -0.58, P less than 0.001). The incidence of IVH in thrombocytopenic infants less than 1500 g was 78%, compared with 48% in the nonthrombocytopenic infants (P less than 0.01). In addition, the more severe grades of IVH were more frequent in the thrombocytopenic infants. The serious neurologic morbidity for the surviving infants less than 1500 g was 41% in the thrombocytopenic infants and 7% in the nonthrombocytopenic infants. Thus, on the basis of three indices of abnormal bleeding, thrombocytopenic infants are at greater risk for bleeding than equally sick nonthrombocytopenic infants. The thrombocytopenia itself may have contributed to the high mortality and neurologic morbidity.
Thrombocytopenia is a common occurrence (20%) in sick neonates, but the causes have not been well studied. In this report we demonstrate that thrombocytopenia in the neonate is characterized by increased platelet destruction as shown by shortened homologous 111In-oxine-labeled platelet life spans. Thirty-one prospectively studied thrombocytopenic neonates were investigated by measuring the 111In-labeled platelet life span, platelet-associated IgG (PAIgG), and coagulation screening tests. In every infant, the thrombocytopenia was shown to have a destructive component since the mean platelet life span was significantly shortened to 65 +/- 6 (mean +/- SEM) hours with a range of one to 128 hours compared with adult values (212 +/- 8; range, 140 to 260; gamma function analysis). The platelet survival was directly related to the lowest platelet count and inversely related to both the highest mean platelet volume and duration of the thrombocytopenia. In 22 infants the percent recovery of the radiolabeled platelets was less than 50%, which suggested that increased sequestration also contributed to the thrombocytopenia. Infants with laboratory evidence of disseminated intravascular coagulation (n = 8) or immune platelet destruction evidenced by elevated levels of PAIgG (n = 13) had even shorter platelet survivals and a more severe thrombocytopenia compared with the ten infants in whom an underlying cause for the thrombocytopenia was not apparent. Full-body scintigraphic images obtained in 11 infants showed an increased uptake in the spleen and liver, with a spleen-to-liver ratio of 3:1. This study indicates that thrombocytopenia in sick neonates is primarily destructive, with a subgroup having evidence of increased platelet sequestration.
We performed a 1-year prospective study of 807 consecutive infants admitted to a regional neonatal intensive care unit to determine the frequency, natural history, mechanism(s), and cause of thrombocytopenia. Thrombocytopenia developed in 22% of the infants. The platelet count nadir usually occurred by day 4 and resolved by day 10. Possible mechanisms responsible for the thrombocytopenia were assessed by comparing mean platelet volume, platelet-associated IgG (PAIgG), and coagulation test results in those infants whose platelet count fell below 100 X 10(9)/L (n = 97) with values in age-, weight-, and disease-matched control infants without thrombocytopenia (n = 80). In some thrombocytopenic infants, 111In-labeled-platelet survival, an estimate of megakaryocyte number in bone marrow biopsy specimens obtained at autopsy, and response to platelet infusions were also assessed. The thrombocytopenia was caused by increased platelet destruction, as shown by short 111In-labeled-platelet survival (12 to 128 hours), a rising mean platelet volume during the first week of life, normal numbers of megakaryocytes, and a poorer than predicted response to platelet infusions. A potential cause for the thrombocytopenia could be found in the majority of infants: 52% had elevated levels of PAIgG, 21% had laboratory evidence of disseminated intravascular coagulation, and 12% had had exchange transfusions. In contrast, the control infants had normal coagulation assay results, and only 15% had elevated levels of PAIgG. Birth asphyxia was identified as an associated risk factor for thrombocytopenia. This study demonstrates that transient, destructive thrombocytopenia develops in a large proportion (22%) of infants admitted to a neonatal intensive care unit, and that birth asphyxia is an important risk factor.
The occurrence of second malignant neoplasms (SMN) in children who survive their primary malignancy is a major cause for concern. Two children with diagnoses of intermediate-risk acute lymphoblastic leukemia (ALL) at 22 months and 2 years of age were treated with multiagent chemotherapy and prophylactic cranial irradiation. They experienced painless parotid swelling 6 and 7 years after successful treatment of the ALL. The patients underwent total parotidectomy, and a diagnosis of mucoepidermoid carcinoma was made. Both patients experienced transient facial nerve paresis. The incidence of SMN in children successfully treated for primary malignancies is 3% to 12%. Salivary gland tumors are being increasingly described in this setting. Long-term follow-up for survivors of childhood ALL is recommended with prompt assessment and resection of parotid swellings, particularly in children who have received cranial irradiation.