Global activation of oncogenic pathways underlies therapy resistance in diffuse midline glioma.

Diffuse midline gliomas (DMGs) are aggressive pediatric brain tumors with dismal prognosis due to therapy-resistant tumor growth and invasion. We performed the first integrated histologic/genomic/proteomic analysis of 21 foci from three pontine DMG cases with supratentorial dissemination. Histone H3.3-K27M was the driver mutation, usually at high variant allele fraction due to recurrent chromosome 1q copy number gain, in combination with germline variants in ATM, FANCM and MYCN genes. Both previously reported and novel recurrent copy number variations and somatic pathogenic mutations in chromatin remodeling, DNA damage response and PI3K/MAPK growth pathways were variably detected, either in multiple or isolated foci. Proteomic analysis showed global upregulation of histone H3, lack of H3-K27 trimethylation, and further impairment of polycomb repressive complex 2 by ASXL1 downregulation. Activation of oncogenic pathways resulted from combined upregulation of N-MYC, SOX2, p65/p50 NF-κB and STAT3 transcription factors, EGFR, FGFR2, PDGFRα/ß receptor tyrosine kinases, and downregulation of PHLPP1/2, PTEN and p16/INK4A tumor suppressors. Upregulation of SMAD4, PAI-1, CD44, and c-SRC in multiple foci most likely contributed to invasiveness. This integrated comprehensive analysis revealed a complex spatiotemporal evolution in diffuse intrisic pontine glioma, recommending pontine and cerebellar biopsies for accurate populational genetic characterization, and delineated common signaling pathways and potential therapeutic targets. It also revealed an unsuspected activation of a multitude of oncogenic pathways, including cancer cell reprogramming, explaining the resistance of DMG to current therapies.

Assessment of ICAM-1 N-glycoforms in mouse and human models of endothelial dysfunction.

Endothelial dysfunction is a critical event in vascular inflammation characterized, in part, by elevated surface expression of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1). ICAM-1 is heavily N-glycosylated, and like other surface proteins, it is largely presumed that fully processed, complex N-glycoforms are dominant. However, our recent studies suggest that hypoglycosylated or high mannose (HM)-ICAM-1 N-glycoforms are also expressed on the cell surface during endothelial dysfunction, and have higher affinity for monocyte adhesion and regulate outside-in endothelial signaling by different mechanisms. Whether different ICAM-1 N-glycoforms are expressed in vivo during disease is unknown. In this study, using the proximity ligation assay, we assessed the relative formation of high mannose, hybrid and complex α-2,6-sialyated N-glycoforms of ICAM-1 in human and mouse models of atherosclerosis, as well as in arteriovenous fistulas (AVF) of patients on hemodialysis. Our data demonstrates that ICAM-1 harboring HM or hybrid epitopes as well as ICAM-1 bearing α-2,6-sialylated epitopes are present in human and mouse atherosclerotic lesions. Further, HM-ICAM-1 positively associated with increased macrophage burden in lesions as assessed by CD68 staining, whereas α-2,6-sialylated ICAM-1 did not. Finally, both HM and α-2,6-sialylated ICAM-1 N-glycoforms were present in hemodialysis patients who had AVF maturation failure compared to successful AVF maturation. Collectively, these data provide evidence that HM- ICAM-1 N-glycoforms are present in vivo, and at levels similar to complex α-2,6-sialylated ICAM-1 underscoring the need to better understand their roles in modulating vascular inflammation.

Dynamic Contrast-Enhanced MRI in Patients with Brain Metastases Undergoing Laser Interstitial Thermal Therapy: A Pilot Study.

BACKGROUND AND PURPOSE: Tumor recurrence is difficult to predict in patients receiving laser ablation for intracranial malignancy. We assessed the efficacy of the initial area under the time-to-signal intensity curve at 60 seconds (iAUC60) from dynamic contrast-enhanced MR imaging in predicting progression-free survival in patients with brain metastases following laser interstitial thermal therapy. MATERIALS AND METHODS: The study population was a consecutive series of patients undergoing laser interstitial thermal therapy for brain metastases. Patient demographics including age, sex, tumor histology, and Karnofsky Performance Scale were collected prospectively. Preoperative, postoperative, and 1-month follow-up dynamic contrast-enhanced MRIs were analyzed. Values of iAUC60 were computed using a trapezoidal rule applied to the time history of contrast uptake over the first 60 seconds postenhancement. The change in iAUC60 (ΔiAUC60) was calculated by taking the difference between the values of iAUC60 from 2 time points. Pearson correlation coefficients were calculated between progression-free survival, defined as the time from laser interstitial thermal therapy to tumor recurrence, and iAUC60 or ΔiAUC60 values. RESULTS: Thirty-three cases of laser interstitial thermal therapy for 32 brain metastases in a cohort of 27 patients were prospectively analyzed. A significant relationship was observed between the values of iAUC60 from postoperative dynamic contrast-enhanced MR imaging and progression-free survival with Pearson correlation (P = .03) and Cox univariate analysis (P = .01). The relationship between preoperative and 1-month follow-up dynamic contrast-enhanced MR imaging was not significantly correlated with progression-free survival. Similarly, no statistically significant relationship was observed with ΔiAUC60 and progression-free survival between any time points. CONCLUSIONS: Progression-free survival is difficult to predict in patients undergoing laser interstitial thermal therapy for brain metastases due to confounding with posttreatment change. iAUC60 extracted from postoperative dynamic contrast-enhanced MR imaging shows promise for accurately prognosticating patients following this operative therapy.

Renal damage detected by DMSA, despite normal renal ultrasound, in children with febrile UTI.

OBJECTIVES: 2011 American Academy of Pediatrics guidelines recommended renal-bladder ultrasound (RBUS) as the only evaluation after febrile urinary tract infection (FUTI) in infants aged 2-24 months. We determined the sensitivity, specificity, and false negative rate of RBUS to identify DMSA-detected renal damage in this age group as well as in older children. METHODS: Consecutive patients referred to pediatric urology with a history of FUTI underwent DMSA ≥ 3 months after FUTI. Abnormal RBUS was defined as: Society of Fetal Urology hydronephrosis grades I-IV; hydroureter ≥ 7 mm; renal scar defined as focal parenchymal thinning; and/or size discrepancy ≥ 1 cm between kidneys. Abnormal DMSA was presence of any focal uptake defects and/or split renal function < 44%. We calculated sensitivity, specificity, positive and negative predictive values, and false negative rates of RBUS compared to DMSA. RESULTS: 618 patients (79% female), median age 3.4 years, were referred for FUTIs. Of the 512 (83%) with normal RBUS, 99 (19%) had abnormal DMSA. Children with normal RBUS after their first FUTI had abnormal DMSA in 15/151 (10%) aged ≤ 24 months and 23/119 (19%) aged > 24 months. RBUS had poor sensitivity (34%) and low positive predictive value (47%) to identify patients with renal damage. 99/149 (66%) children with renal damage on DMSA had normal RBUS. CONCLUSION: After FUTI, 66% of children with reduced renal function and/or renal cortical defects found by DMSA scintigraphy had a normal RBUS. Since abnormal DMSA may correlate with increased risk for VUR, recurrent FUTI and renal damage, our data suggest RBUS alone will fail to detect a significant proportion of patients at risk. The data suggest that imaging after FUTI should include acute RBUS and delayed DMSA, reserving VCUG for patients with abnormal DMSA and/or recurrent FUTI.

Year-to-year correlations in blood metal levels among individuals of two species of North American sea ducks.

Sea duck populations have declined in North America. Contaminants, especially metals, have been listed as possible contributing factors. Sea ducks are long-lived. Thus, individuals chronically exposed to elevated metal levels may be at greatest risk. Information about long-term exposure (> or =1year) of individuals to metals is absent. To address this information gap, we examined year-to-year correlations among individual White-Winged Scoters and King Eiders in levels of blood cadmium, lead, mercury and selenium. Positive correlations (r> or =0.43), were found in six, five, five and two of seven correlations for cadmium, selenium, lead and mercury. Thus, certain individuals of these species may be exposed over two or more years to higher levels of cadmium, selenium and lead (but apparently not mercury) than other individuals. Single blood samples are appropriate metrics of exposure for studies that examine long-term effects of certain metals on these birds.

Positron emission tomography: a first-hand experience.

In July 1999, the University of Kansas Hospital installed a positron emission tomography (PET) scanner and added PET to the imaging technologies it offers patients and physicians. The new service is managed by the nuclear medicine section in the department of radiology. Plans are being implemented now to install a cyclotron in March 2000. Prior to installation of the scanner, a radiation area survey was performed in the space being considered for the PET unit. We also needed to address other critical considerations, including the manufacturer's requirements for construction of the scanner room, special electrical needs, and how the system would connect to our existing information network. It is important to work closely with your chief financial officer and chief operations officer from the beginning of the purchasing process so that these administrators have up-to-date, supportive information about PET and the progress of the installation. We made use of a variety of promotional techniques to market the new service, including broadcast e-mail, an open house for potential referring physicians, postings on the nuclear medicine Web site and communication through the local media. We also worked with the major insurance providers that utilize our hospital to educate them about PET and its benefits. In addition, we trained our own billing staff about procedures that optimize reimbursement for PET. In March 2000, University of Kansas Hospital will install the first cyclotron in the state, enabling us to generate the drugs used for PET scanning and potentially to add targets for research PET radiopharmaceuticals.

Data-gathering tools for "real world" clinical settings: a multisite feasibility study.

OBJECTIVE: To determine the mental health needs and optimal treatments for children and families in "real world" settings, data-gathering strategies are needed that can be easily implemented across a variety of clinical settings. To address this need, the authors developed and piloted a "clinician-friendly" questionnaire that includes demographic, psychosocial, medical, and family history variables, such as those routinely gathered in standard clinical evaluations. METHOD: Optical scanning technology was used to encode data from more than 1,900 children, including 1,458 consecutive referrals in four military child psychiatry clinics, 285 consecutive admissions to a civilian psychiatric state hospital, 71 pediatric patients, and a community sample of 113 children. RESULTS: Despite geographic and logistic obstacles, clinical data were reliably obtained across multiple settings. Data analyses revealed meaningful differences across samples in subjects' presenting complaints, and a range of psychosocial, demographic, and background variables. Data were characterized by an apparently high degree of accuracy and completeness. CONCLUSIONS: Findings illustrate the importance and feasibility of standardized data-gathering approaches in routine clinical settings and clarify the hazards as well as the opportunities afforded by these research approaches. Such data-gathering tools appear to have significant merit and deserve further implementation and testing across a range of clinical and research settings.

Assessing the influence of maternal depression on the validity of the Child Behavior Checklist.

The relative effects of maternal depression, child gender, and child psychiatric status on mothers' ratings of their children were assessed in a study of the validity of the Child Behavior Checklist (CBCL). Both maternal depression and gender were found to be significantly associated with mothers' ratings of their children on the CBCL. Nevertheless, mothers' ratings continued to differentiate groups of children with and without psychiatric problems even after the variance accounted for by maternal depression and child gender was removed. These findings support the criterion validity of the CBCL, and point also to the importance of assessing parents as part of the clinical evaluation of children.

Gastrointestinal response to oral versus gastric feeding of defined formula diets.

The gastrointestinal response in rats nourished by continuous intragastric infusion of a variety of defined formula diets was compared with animals consuming the same diets orally. Two groups of rats were fed isocaloric amounts of DFD (73 kcal/day); group 1: sham-operated, orally-fed; group 2: operated, intragastrically-fed. Diets included; Vivonex (V), Flexical (F), Vital, Vivonex high nitrogen, and a control casein rat liquid formula diet (C). After 2 wk rats were killed and the liver, pancreas, and small bowel removed. The bowel was divided into eight equal segments. Mucosal weight, DNA, and protein concentration per cm segment were measured Pancreatic amylase activity (units/g), and liver weight and lipid content were measured. Weight gain was comparable in all oral-fed groups, but was decreased in all gastric-fed animals compared to the oral-fed group. Nitrogen retention was not influenced by route of feeding but was significantly lower for Vivonex and Flexical animals (p less than 0.01) in both oral-fed and gastric-fed groups. There was significant accumulation of lipid in the liver of both oral-fed and gastric-fed animals sustained on Vivonex and Vivonex high nitrogen (p less than 0.01). Most proximal intestinal segment weight and mucosal weight, protein and DNA were decreased compared to the control diet in both oral-fed and gastric-fed animals. These studies demonstrate that while the gastrointestinal response to isocaloric defined formula diets was significantly influenced by the specific diet, fewer responses were modified by feeding defined formula diets orally versus gastrically.

Gastrointestinal response to nutrient variation of defined formula diets.

The gastrointestinal response to oral alimentation of low residue commercial defined formula diets or a rat liquid formula was studied. Male Sprague-Dawley rats (220-250 g) were fed isocaloric amounts (73 kcal/day) of Vivonex (V), Vivonex HN (VHN), Flexical (F), Vital (Vit), or a control Casein diet 116EC (C). Nitrogen (N) retention was calculated from N intake minus N excretion/day. After 2 weeks, rats were killed and the liver, pancreas, and small bowel removed and weighed. Pancreatic amylase activity (U g) and liver lipid were measured. The bowel was divided into eight equal segments, and mucosal weight, DNA, and protein concentration per centimeter were measured. Despite isocaloric feeding, body weight gain was lower in V and VHN groups, and higher in F and Vit groups compared to the C. Amylase specific activity was increased in V, VHN, and F groups, while the liver lipid was increased in the V and VHN groups when compared to C animals. The most proximal intestinal segment weight, mucosal weight, protein and DNA of V, VHN, and Vit groups were less than C animals, while distal segments were similar. F animals showed greater intestinal mass than C rats. These studies indicate statistically significant differences in gastrointestinal response as a result of nutrient variation of defined formula diets.

Stimulation of mucosal growth by gastric and ileal infusion of single amino acids in parenterally nourished rats.

The effect on the intestinal mucosa of continuously infusing single amino acids, glycine, valine and histidine into the stomach and ileum was compared with saline and an amino acid mixture (AA) in rats fed to parenteral nutrition. After gastric infusion, glycine did not differ from saline, valine increased mucosa in the proximal segments and histidine alone increased mucosa in the proximal bowel equal to AA. After ileal infusion, all amino acids increased mucosa in the ileum. Valine and histidine, but not glycine, increased mucosa in the remote proximal small bowel. Therefore, regional differences occur in mucosal growth response to single amino acids.

Comparative study of nutritional adaptation to defined formula diets in rats.

Little is known about the specific effects of defined formula diets (DFD) on mucosal growth of the small intestine, pancreas, or liver. In the present study male Sprague Dawley rats weighing 220 to 250 g were fed isocaloric amounts of DFD (61 kcal/day) by continuous intragastric infusion. The diets fed were Vivonex, Vivonex-HN, Flexical, and Ensure. Oral chow-fed rats with intragastric water infusions served as reference. All groups gained weight: chow 50.50 g, Vivonex 21.17 g (P < 0.005), Vivonex-HN 25.40 g (P < 0.005), Flexical 30.5 g (P < 0.01), Ensure 39.29 g (NS). After 2 weeks rats were killed, the small bowel excised, rinsed, and divided into eight equal segments. Mucosal weight, DNA, and protein concentration per centimeter segment were measured. The pancreas was also removed, homogenized, and amylase activity assayed (units/g). Livers were excised, weighed, lipid content measured, and liver histology was examined by light microscopy. Mucosal weight, DNA, and protein concentrations per segment were decreased significantly in most bowel segments of DFD fed rats. Amylase activity per gram pancreas was significantly reduced in rats fed Vivonex, Flexical, and Ensure, Serum amylase activity was also lowered in animals on DFD. There was significant accumulation of lipid in the liver of Vivonex and Flexical animals (P < 0.01). Liver histology confirmed the striking increase in fat in the Vivonex and Flexical groups. These effects may result from differences in DFD absorption, mucosal metabolism, stimulation of enteric hormone release, and/or bile and pancreatic secretions.