Study Objective-To investigate potential associations between the histamine Nmethyltransferase (HNMT) C314T (Thr105Ile) polymorphism and atopic dermatitis (AD) in a cohort of Caucasian children.Design-Prospective, multi-center (n=4) genotype/association study. Setting-Four academic, tertiary care, medical centers within the Pediatric Pharmacology Research Unit (PPRU) networkPatients or Participants-Caucasian children ages 6 months -5 years with (n=129) and without (n=127) AD. All subjects completed the study although data from 6 subjects (n=2 AD and n=4 control) were excluded due to violations in inclusion/exclusion criteria (n=5) and the informed consent process (n=1).Interventions-Information was collected regarding severity of AD, oral antihistamine treatment and treatment response via parental report. Buccal swabs (n=1 per cheek) were also performed to obtain epithelial cells for extraction of genomic DNA.Measurements and Main results-HMNT genotypes were successfully obtained in 116 and 122 control and AD subjects, respectively. Frequencies of the T314 variant allele (0.12, p=0.04) and combined CT/TT genotype (0.24, p=0.02) were significantly higher in children with AD compared with controls (allele and genotype frequencies = 0.06 and 0.12). Children with genotypes conferring reduced HNMT activity were two times more likely to have AD than those who were homozygous for the C314 reference allele.Conclusions-Increased histamine levels in patients with AD may result, at least in part, from reduced inactivation via HNMT. Genetically-associated reduction in histamine biotransformation may therefore contribute to the pathogenesis, persistence and progression of AD. If confirmed, these data indicate that HNMT might represent a common risk factor for development of AD, asthma and allergic rhinitis and may be useful in identifying individuals who are candidates for early preventative pharmacotherapeutic intervention. Additional longitudinal studies will be required in order to assess the relationship between genotype, disease severity and antihistamine response. NIH Public Access

Purpose: A genome-wide scan of 175 hereditary prostate cancer families from the University of Michigan Prostate Cancer Genetics Project provided evidence of prostate cancer linkage to 17q markers near the BRCA1 gene. To examine the possibility that germ-line BRCA1 mutations were associated with hereditary prostate cancer, individuals from 93 families with evidence of linkage to chromosome 17q were screened for germ-line BRCA1 mutations.Experimental Design: One individual from each of the 93 families, the majority with three or more cases of prostate cancer, were screened for BRCA1 mutations with denaturing high-performance liquid chromatography (HPLC). Fragments exhibiting denaturing HPLC variant patterns were additionally analyzed by direct sequencing.Results: Sixty-five of the individuals selected for sequencing from 65 unrelated families were determined to have wild-type BRCA1 sequence by denaturing HPLC. One individual from a family with both prostate and ovarian cancer was found to have a truncating BRCA1 mutation (3829delT). An additional 27 germ-line variants were identified, including 15 missense variants.Conclusions: These sequencing results suggest that BRCA1 truncating mutations do not account for the linkage evidence on chromosome 17 observed in University of Michigan Prostate Cancer Genetics Project families. A recently completed combined genome scan has also detected linkage to 17q22, and studies are ongoing to identify the relevant prostate cancer susceptibility gene in this region.

Urinary proteomic profiling has potential to identify candidate biomarkers of renal injury in infants provided an adequate urine sample can be obtained. Although diapers are used to obtain urine for clinical evaluation, their use for proteomic analysis has not been investigated. We therefore performed feasibility studies on the use of diaper-extracted urine for 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Pediatric waste urine (2-20 mL) was applied to gel-containing, non-gel and cotton-gauze diapers and then mechanically expressed. Urine volume and total protein were measured pre-and post-extraction. Proteins were separated via 2D-PAGE following application of urine (20-40 mL) to each matrix. 2D-PAGE was also performed on clinical specimens collected using each diaper type. Differences in the adsorption and retention of urine volume and protein were noted between matrices. Non-gel and cotton-gauze diapers provided the best protein/volume recovery and the lowest interference with the Bradford assay. 2D-PAGE was also successfully completed using urine samples from both cotton fiber matrices. Conversely, samples from low-gel diapers demonstrated poor protein separation and reproducibility. Diapers containing cotton-fiber matrices appear adequate for 2D-PAGE. Qualitative and quantitative analyses of resolved proteins using replicate, high resolution gels will be required, however, before diaper-extracted urine can be applied in proteomic profiling.