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Biomedical subjects

James E Heubi

Publications and source records attributed to James E Heubi.

25 records · Page 2Linked to original sources
PubMed2003

Prevalence of reduced bone mass in children and adults with spastic quadriplegia.

This study was designed to test the hypothesis that non-ambulatory patients with spastic quadriplegia will have reduced bone mass which worsens with increasing age. Forty-eight patients (age 5 to 48 years, median age 15 years; 19 females and 29 males) were studied. Anticonvulsants were used in 29 patients (60.4%). Lumbar spine bone mineral density (LS-BMD) was markedly reduced compared with age-and sex-matched control individuals with a z score of -2.37 +/- 0.21. Twenty-eight (58%) had z scores of less than -2. A history of documented previous fracture was present in 19 patients (39%). Patients with a history of fracture had significantly lower (p = 0.05) LS-BMD z scores (-2.81 +/- 0.29) compared with those without a history of fracture (-2.11 +/- 0.26). Mean serum 25-OH vitamin D was 29.6 +/- 1.9ng/mL (normal 9 to 37.6ng/mL) with three patients having serum 25-OH vitamin D levels less than 15ng/mL. These findings indicate that BMD is markedly reduced in non-ambulatory children and adults with neuromuscular disease. Reductions in bone mass put them at greater risk for non-traumatic fractures.

Absorptiometry, Photon↗
PubMed2002

Monozygotic twins with a severe form of Alagille syndrome and phenotypic discordance.

Alagille syndrome is an autosomal dominant disorder affecting multiple organ systems, predominantly the liver, heart, skeleton, eye, face, and kidney. The phenotype in Alagille syndrome is highly variable both within and between families. We report monozygotic twins with Alagille syndrome concordant for a mutation in Jagged1 but discordant for clinical phenotype. The twins' monozygosity was confirmed by molecular testing. A de novo splice site mutation was identified in exon 6 (1329 + 2T --> G) in both children. Both twins display a severe form of Alagille syndrome; however, one twin has a severe pulmonary atresia with mild liver involvement, while the other has tetralogy of Fallot and severe hepatic involvement, which has required liver transplantation. Potential mechanisms for phenotypic variability among monozygotic twins are discussed. This is the first reported case of discordance in phenotype in monozygotic twins with Alagille syndrome. This case implies that genotypic variations alone do not explain the clinical variability seen in Alagille syndrome and supports the contributory role of nongenetic factors in phenotype determination.

Alagille Syndrome↗
PubMed2002

Tauroursodeoxycholic acid (TUDCA) in the prevention of total parenteral nutrition-associated liver disease.

OBJECTIVE: To determine whether tauroursodeoxycholic acid (TUDCA) would prevent or ameliorate the liver injury in neonates treated with total parenteral nutrition (TPN). STUDY DESIGN: Eligible infants were enrolled after surgery when serum direct bilirubin (DB) was <2 mg/dL. TUDCA (30 mg/kg/day) was given enterally to 22 subjects. A concurrent untreated/placebo group was evaluated for comparison (n = 30). Blood chemistries including alanine aminotransferase (ALT), alkaline phosphatase (AP), conjugated bilirubin (CB), and bile acids (BA) were obtained weekly. RESULTS: There was no difference in peak serum CB, ALT, AP, or BA levels between the TUDCA-treated and control infants. When stratified for birth weight (<1500 g and >1500 g), no differences in peak CB, ALT, AP, or BA were noted. Serum CB levels were similar between TUDCA-treated and control infants after 14, 40, 60, 70, and 120 days of TPN. CONCLUSION: TUDCA appears ineffective in preventing the development or treatment of TPN-associated cholestasis in neonates. Erratic biliary enrichment and prolonged inability to initiate treatment may compromise the utility of enterically administered TUDCA for TPN-treated infants.

Alanine Transaminase↗
PubMed2002

Evidence for lack of absorption of soy isoflavone glycosides in humans, supporting the crucial role of intestinal metabolism for bioavailability.

BACKGROUND: The isoflavones daidzein and genistein occur naturally in most soyfoods, conjugated almost exclusively to sugars. Controversy exists regarding the extent of bioavailability of isoflavone glycosides, and the mechanism of intestinal absorption of isoflavones in humans is unclear. Evidence from intestinal perfusion and in vitro cell culture studies indicates that isoflavone glycosides are poorly absorbed, yet isoflavones are bioavailable and appear in high concentrations in plasma, irrespective of whether they are ingested as aglycones or glycoside conjugates. OBJECTIVE: The objective was to determine whether isoflavone glycosides are absorbed from the intestine intact and reach the peripheral circulation unchanged. DESIGN: Plasma was collected at timed intervals before and after healthy adults ingested 50 mg of one of the isoflavone beta-glycosides (daidzin or genistin) or 250 mL soymilk containing mainly isoflavone glycosides. Electrospray ionization mass spectrometry was used to detect daidzin and genistin after solid-phase extraction of these conjugates from plasma. Bioavailability of isoflavones was confirmed by gas chromatography-mass spectrometry analysis. RESULTS: Specific and sensitive electrospray mass spectrometry failed to detect even traces of daidzin or genistin in plasma collected 1, 2, and 8 h after their ingestion as pure compounds or in a soyfood matrix. However, plasma was enriched in isoflavones that were hydrolyzable with a combined beta-glucuronidase and sulfatase enzyme preparation. CONCLUSION: Isoflavone glycosides are not absorbed intact across the enterocyte of healthy adults, and their bioavailability requires initial hydrolysis of the sugar moiety by intestinal beta-glucosidases for uptake to the peripheral circulation.

Adult↗
PubMed2002

Separation of micelles and vesicles within lumenal aspirates from healthy humans: solubilization of cholesterol after a meal.

Understanding the physico-chemical relationship of lumenal lipids to one another is critical when elucidating the mechanism of components known to impact cholesterol absorption. Presently, there are no studies that describe the proportion of cholesterol carried as micelles or vesicles within human lumenal contents. Part of the reason for the scarceness of data is because of the lack of appropriate methodology required for reproducible sample collection and analysis. Thus, the object of the present studies was to develop a method to measure the amount of cholesterol carried as micelles or vesicles in human lumenal samples. The method includes the collection of lumenal samples from the ligament of Trietz through a Fredrick Miller tube, separation of the aqueous subphase from the nondigested lipids, separation of micelles and vesicles on Sepharose 4B columns within 48 h of collection using elution buffers consisting of the intermicellar bile acid composition, and finally quantitation of cholesterol eluted off of the columns. The distribution of cholesterol between micelles and vesicles obtained under different concentrations of bile acids and various lipids was comparable to results obtained from phase diagrams using the lumenal molar percentages of lipids obtained from the same samples.

Adult↗