Abdominal X-ray in Pediatric Acute Severe Colitis and Radiographic Predictors of Response to Intravenous Steroids.

BACKGROUND: Abdominal x-ray (AXR) can identify complications in acute severe colitis (ASC) and may assist in selecting high-risk children for early aggressive treatment. We aimed to describe AXR findings in pediatric ASC and to explore radiological predictors of response to intravenous corticosteroid (IVCS) therapy. METHODS: A total of 56 children with ASC were included in a multicenter, retrospective 1-year cohort study (41% boys, mean age 12.1 ±â€Š4.2). Radiographs of responders to IVCS and those requiring second-line salvage therapy by discharge were analyzed independently by 2 blinded radiologists. RESULTS: A total of 33 responders to IVCS were compared with 23 nonresponders. The day-3 Pediatric Ulcerative Colitis Activity Index (PUCAI) score was significantly higher in nonresponders (63 ±â€Š16 vs 46 ±â€Š21, P = 0.001). The mean transverse colon luminal diameter was 30 ±â€Š16 mm in responders and 38 ±â€Š16 mm in nonresponders (P = 0.94). The upper range of transverse colonic diameter in children <12 years was ∼40 mm, whereas in older children it was 60 mm as accepted in adults. Ulcerations and megacolon seen on AXR were associated with nonresponse to IVCS (P = 0.006 and 0.064, respectively). CONCLUSIONS: The presence of mucosal ulcerations and megacolon on AXR could be considered in the risk stratification of children with ASC for early aggressive treatment, together with the previously known day-3 and day-5 Pediatric Ulcerative Colitis Activity Index scores, albumin, and C-reactive protein.

Pituitary tumors in MEN1: do not be misled by borderline elevated prolactin levels.

PURPOSE: The objective of this case report is to demonstrate that the simple expedient of measuring periodic prolactin levels in patients with MEN1 who have modest hyperprolactinemia and normal pituitary MRI scans is insufficient to monitor for the development of pituitary adenomas. METHODS: Review of relevant literature and chart review. RESULTS: A 25 year old man with known MEN1 manifested by hyperparathyroidism and a gastrin-producing neuroendocrine tumor was found to have a prolactin [PRL] level of 20.0 ng/mL [1.6-16 ng/mL] but a normal pituitary MRI scan. The impression then was that he had prolactinoma too small to be visualized on the MRI. Over the next 3.5 years his PRL levels remained in this mildly elevated range but he then presented with severe headaches and visual field defects. An MRI showed a 3.1 × 1.7 × 1.9 cm pituitary adenoma with compression of the optic chiasm and invasion of the left cavernous sinus. Surgery revealed a gonadotroph adenoma and he subsequently required gamma knife radiotherapy for residual tumor. Postoperative PRL levels were normal. CONCLUSIONS: Small, intrasellar microadenomas may be associated with elevated PRL levels due to possible direct hormone production [prolactinoma] or possibly to interference with portal vessel blood flow. In monitoring hyperprolactinemic MEN1 patients for the development of pituitary adenomas, measurement of PRL levels is insufficient and periodic MRI scans are necessary at a more frequent interval than every 3-5 years. This may also pertain to patients with "idiopathic" hyperprolactinemia.

Novel 3-hydroxy vinylboronates influence sphingolipid metabolism, cause apoptosis in Jurkat cells and prevent tumor development in nude mice.

A series of novel 3-hydroxy vinylboronates which share structural similarities with sphingolipids were synthesized and tested in vitro and in vivo as anticancer agents. The molecules reduced cancer cell survival in vitro by influencing their sphingolipid metabolism. In a cancer model in nude mice the lead compound E7 prevented the development of tumor as long as the treatment period continued. Moreover, it delayed tumor growth after the treatment was finished.

Thiopurine pharmacogenomics: association of SNPs with clinical response and functional validation of candidate genes.

AIM: We investigated candidate genes associated with thiopurine metabolism and clinical response in childhood acute lymphoblastic leukemia. MATERIALS & METHODS: We performed genome-wide SNP association studies of 6-thioguanine and 6-mercaptopurine cytotoxicity using lymphoblastoid cell lines. We then genotyped the top SNPs associated with lymphoblastoid cell line cytotoxicity, together with tagSNPs for genes in the 'thiopurine pathway' (686 total SNPs), in DNA from 589 Caucasian UK ALL97 patients. Functional validation studies were performed by siRNA knockdown in cancer cell lines. RESULTS: SNPs in the thiopurine pathway genes ABCC4, ABCC5, IMPDH1, ITPA, SLC28A3 and XDH, and SNPs located within or near ATP6AP2, FRMD4B, GNG2, KCNMA1 and NME1, were associated with clinical response and measures of thiopurine metabolism. Functional validation showed shifts in cytotoxicity for these genes. CONCLUSION: The clinical response to thiopurines may be regulated by variation in known thiopurine pathway genes and additional novel genes outside of the thiopurine pathway.

Haptoglobin: basic and clinical aspects.

Haptoglobin is an abundant hemoglobin-binding protein present in the plasma. The function of haptoglobin is primarily to determine the fate of hemoglobin released from red blood cells after either intravascular or extravascular hemolysis. There are two common alleles at the Hp genetic locus denoted 1 and 2. There are functional differences between the Hp 1 and Hp 2 protein products in protecting against hemoglobin-driven oxidative stress that appear to have important clinical significance. In particular, individuals with the Hp 2-2 genotype and diabetes mellitus appear to be at significantly higher risk of microvascular and macrovascular complications. A pharmacogenomic strategy of administering high dose antioxidants specifically to Hp 2-2 DM individuals may be clinically effective.

Structural elucidation of a novel DNA-DNA cross-link of 1,2,3,4-diepoxybutane.

DNA-DNA cross-linking by 1,2,3,4-diepoxybutane (DEB) is considered the molecular basis for its potent cytotoxic and genotoxic effects. DEB reactions with DNA initially lead to N7-(2'-hydroxy-3',4'-epoxybut-1'-yl)-guanine monoadducts, which can then alkylate neighboring DNA bases to form bifunctional lesions. We recently reported the structures of four regioisomeric guanine-adenine adducts of DEB involving the N7 position of guanine and the N1, N3, N6, and N7 positions of adenine (Park, S., et al. (2004) Chemical Research in Toxicology 17, 1638-1651). In the present work, a novel bifunctional DNA lesion of DEB was identified as 1-(hypoxanth-1-yl)-4-(guan-7-yl)-2,3-butanediol (N1HX-N7G-BD). An authentic standard of N1HX-N7G-BD was prepared and structurally characterized by proton NMR, UV, and mass spectrometry. HPLC-ESI-MS/MS analyses of acid hydrolysates of DEB-treated calf thymus DNA revealed a peak that had the same retention time, MS/MS fragmentation, and UV spectrum as the authentic standard of N1HX-N7G-BD. We propose that N1HX-N7G-BD is formed by the hydrolytic deamination of previously reported 1-(aden-1-yl)-4-(guan-7-yl)-2,3-butanediol. Although N1HX-N7G-BD adducts are less abundant in DEB-treated DNA than the corresponding guanine-guanine cross-links, they may play a role in the induction of both AT and GC base pair mutations.