Terry Law

Late onset of renal and hepatic cysts in Pkd1 -targeted heterozygotes

disease (ADPKD) due to PKD1 mutations is characterized by the progressive appearance of renal, hepatic and pancreatic cysts in adults1. We previously reported that targeted deletion of exon 34 in Pkd1, the mouse homologue of PKD1, results in renal cysts and perinatal death in homozygotes2. Here we report that Pkd1+/– mice progressively develop scattered renal and hepatic cysts. Serial sections of 15 Pkd1+/– mice of 9–14 months of age revealed 1−7 renal cysts (of more than 5 times the normal tubule diameter) per animal in 12 mice (80%), of which 5 mice had bilateral cysts. After 16 months, 2−50 cysts were found in all 8 mice examined (100%, Table 1) and 6 of 8 mice had bilateral cysts. Renal excretory function (serum creatinine) was normal in all but one mouse with extensive disease. There were no cysts in five, agematched, control littermates. Cysts were seen from the cortex (Fig. 1a) to the inner medulla. Most cysts Late onset of renal and hepatic cysts in Pkd1-targeted heterozygotes correspondence

Vitamins A and E serum levels in children and young adults with inflammatory bowel disease : Effect of disease activity

BACKGROUNDnHypovitaminosis and fat-soluble vitamin deficiency have been reported in adults with inflammatory bowel disease (IBD). A prospective study was undertaken to determine the prevalence of low serum levels of vitamins A and E in children and young adults with IBD.nnnMETHODSnClinical information and serum for vitamin levels was gathered prospectively from 61 patients with Crohns disease, 36 patients with ulcerative colitis, and 23 control subjects. Disease activity and disease location were determined for IBD patients. Serum retinol and alpha-tocopherol levels were determined by high-performance liquid chromatography.nnnRESULTSnThe prevalence of hypovitaminosis A (defined as serum vitamin A < 20 micrograms/dl) or hypovitaminosis E (defined as serum vitamin E < 5 mg/l) was 16% in the pediatric IBD population studied. Low vitamin A levels were more common than low vitamin E levels. Serum retinol levels correlated significantly with alpha-tocopherol levels. Hypovitaminosis was significantly more prevalent in the Crohns disease patients who had active disease, an erythrocyte sedimentation rate of more than 25 mm/hour, or a serum albumin level less than 3 mg/dl.nnnCONCLUSIONSnChildren and young adults with active IBD frequently have low serum levels of vitamin A or vitamin E. The severity of disease activity is a better predictor of risk for hypovitaminosis than is nutritional status. Further work is necessary to determine whether the hypovitaminosis seen in children with IBD reflects true deficiency.

Elevated serum vascular endothelial growth factor in children and young adults with Crohn's disease.

Vascular endothelial growth factor (VEGF) is acytokine released by fibroblasts, epithelial cells, andleukocytes that potentiates vascular permeability andgrowth of new capillaries. Because of these multiple effects, VEGF has been postulated to play arole in the pathogenesis of autoimmune disease, as wellas in wound healing. We hypothesized that VEGF waspotentially important in mediating the vascularpermeability and angiogenesis seen in Crohns disease, andtherefore that VEGF would be increased in the serum ofchildren with Crohns disease. Serum was obtained from73 children and young adults with Crohns disease, 47 with ulcerative colitis, and 29 controls.VEGF levels were measured by enzyme-linked immunosorbentassay. Mean VEGF levels were significantly higher inpatients with Crohns disease (436.4 ± 37.2pg/ml) than in ulcerative colitis (306 ± 41.1pg/ml) or control (167.8 ± 29.6 pg/ml) patients.Serum VEGF also correlated significantly with diseaseactivity, being elevated in patients withmoderate/severe Crohns disease and ulcerative colitis. Weconclude that serum VEGF is released by inflamed tissuesin children with Crohns disease. This multifunctionalcytokine could promote inflammation by increasing vascular permeability or promote wound healingby mediating capillary growth.

Serum basic fibroblast growth factor in pediatric Crohn's disease : Implications for wound healing

Basic fibroblast growth factor is aheparin-binding protein known to stimulate angiogenesisand promote wound healing in tissues. Since Crohnsdisease is characterized in part by submucosal vascularproliferation, we sought to determine whether serum basicfibroblast growth factor is elevated in children withCrohns disease and whether serum levels reflect diseaseactivity. Sera were obtained from 64 children with Crohns disease, 44 children with ulcerativecolitis, 20 children with functional abdominal pain, and29 from children with documented inflammatory diseaseevaluated in our gastroenterology program. Disease activity indices and clinical data weregathered prospectively for the inflammatory boweldisease patients. Serum basic fibroblast growth factorlevels were measured by enzyme-linked immunosorbentassay. Although the mean basic fibroblast growthfactor level did not significantly differ betweenchildren with Crohns disease and other conditions,there was a strong (r = 0.53, P < 0.001) correlationbetween basic fibroblast growth factor level and diseaseactivity. The relationship of basic fibroblast growthfactor with disease activity persisted even afteradjusting for other covariates (including age, sex,hematocrit, albumin, and sedimentation rate) in amultivariate linear regression model. There was also astatistically significant, although less strongcorrelation (r = 0.33, P = 0.03) between basicfibroblast growth factor level and disease activity in ulcerativecolitis. While basic fibroblast growth factor is not aspecific marker for Crohns disease, serum levelsreflect disease activity. Therefore, basic fibroblast growth factor release may be important inmediating the angiogenesis and wound healing seen inCrohns disease.

Elevation of Serum Interleukin-6 but Not Serum-soluble Interleukin-2 Receptor in Children with Crohn's Disease

Previous studies have demonstrated elevated serum levels of interleukin-6 (IL-6) and the soluble interleukin-2 receptor (IL-2R, CD25) in individuals with inflammatory bowel disease (IBD). The aim of our study was to compare serum IL-6 and IL-2R levels to see if one marker better distinguished IBD from other intestinal disorders or better reflected disease activity. Blood samples were obtained from 41 pediatric patients with Crohns disease, 22 with ulcerative colitis, 19 with other gastrointestinal inflammatory disorders, and 13 with functional abdominal pain. Disease activity and disease location were determined for patients with Crohns disease and ulcerative colitis. Serum levels of IL-6 and IL-2R were determined by using an enzyme-linked immunosorbent assay. Mean serum levels of IL-6 were significantly elevated (p < 0.05) in patients with Crohns disease when compared with individuals with ulcerative colitis, other gastrointestinal inflammatory disorders, or functional abdominal pain. By comparison, there was no significant difference in mean serum levels of IL-2R in individuals with Crohns disease compared with these other groups. Patients with moderate/severe Crohns disease had elevated mean serum levels of IL-6 and IL-2R when compared with those with mild and inactive disease (p < 0.05); however, neither marker distinguished between inactive and mild disease. IL-6 correlated better with the erythrocyte sedimentation rate (ESR; r = 0.57, p < 0.001) than did IL-2R (r = 0.28, p < 0.01). Our results suggest that elevated IL-6 levels a.e more likely to be seen in patients with Crohns disease. Although IL-6 may be a better marker for Crohns disease and active disease than IL-2R, it does not appear to offer any advantage over the ESR.

Tandem mass spectrometry method for the quantification of serum busulfan

Busulfan, an alkylating agent, is most commonly used as a component of bone marrow transplantation preoperative regimens. Significant interpatient and intrapatient variations in pharmacokinetics require individualizing the dosage based on area under the time-versus-concentration curve. Timely result reporting is critical to dose adjustment to reduce morbidity and mortality associated with the regimen. The authors developed a rapid, accurate, and sensitive method for the quantification of serum busulfan using direct inject tandem mass spectrometry. Plasma samples (50 μL) are extracted in 1 mL of methanol containing 1,6-bis-(methanesulfonyloxy)hexane as an internal standard. The supernatant is dried under nitrogen (40°C, 30 minutes) and then dissolved in 200 μL methanol and transferred into a clean glass vial suitable for LC/MS/MS analysis. The sample is delivered using an HPLC pump that delivers 0.2 mL of methanol per minute, and 20 μL of sample is injected into a turbo ion spray-equipped tandem mass spectrometer. Total analysis time is 5 minutes. The Q1/Q3 transition for busulfan (BU) is monitored at 269/55 and 297.1/55.1 for the internal standard. The assay is linear to 10 μmol/L and sensitive to at least 0.5 μmol/L. The interassay reproducibility at 1, 2.2, and 4.4 μmol/L were 4.2%, 5.6%, and 6.3%, respectively. Within-run precision using 3 different control samples was 3.9%, 3.9%, and 6.9%. Mean recovery of 4 different BU concentrations spiked into 10 different BU free plasma samples was 98%. Correlation with an established HPLC-UV method revealed a slope of 0.98, an intercept of 0.1, and r2 = 0.95 (n = 48). No significant interfering substances or ion suppression was identified. This method is a significant improvement over the existing HPLC-UV method for BU determination. The method is highly accurate, reproducible, and requires less specimen, sample preparation, and analysis time.

A new liquid homogeneous assay for HDL cholesterol determination evaluated in seven laboratories in Europe and the United States.

Abstract We evaluated a new liquid homogeneous assay for the direct measurement of high density lipoprotein cholesterol (HDL-C Plus) in seven laboratories. The assay includes two reagents which can be readily used in most available clinical chemistry analyzers. The total CVs of the new method were below 4.6% and the bias in relation to the designated comparison method was below 3.9%. The total error ranged between 4 to 7%. HDL-C values determined by this method were in good agreement with those obtained by the old homogeneous assay using lyophilized reagents, and other homogeneous and precipitation assays (0.944 < r < 0.996). The assay was linear up to at least 3.89 mmol/l HDL-C. Hemoglobin did not interfere, whereas in icteric samples slight deviations were observed. Lipemia up to 11.3 to 22.6 mmol/l triglycerides did not interfere with this homogeneous HDL-C assay. In samples of patients with paraproteinemia, discrepant results were seen. This liquid homogeneous HDL-C assay was easy to handle and produced similar results in all laboratories participating in this study. This method will enable clinical laboratories to reliably measure HDL-C for risk assessment of coronary heart disease.