Biomedical subjects

T M Rossi

Publications and source records attributed to T M Rossi.

40 records · Page 3Linked to original sources

PubMedDate not supplied

Reversed-phase liquid chromatography of the opioid peptides. 3. Development of a microanalytical system for opioid peptides involving microbore liquid chromatography, post-column derivatization and laser-induced fluorescence detection.

A microanalytical system has been developed for the determination of peptides in small samples. Naphthalene-2,3-dicarboxaldehyde-beta-mercaptoethanol (NDA-BME) was used as the labelling reagent system as an alternative to NDA-cyanide (NDA-CN) because of the faster labelling when CN was replaced by a thiol. The fluorescence characteristics of the NDA-thiol adducts, N-substituted 1-alkylthiobenz[f]isoindoles (TBIs), were found to be different from the previously described cyanobenz[f]isoindole (CBIs) adducts formed by the reaction of primary amines with NDA-CN. The excitation maximum of the TBI adducts was at 460 nm, which was closer to the 457.9 nm argon-ion laser line, than the 440-nm maximum of the CBI adduct. The limit of detection for leucine enkephalin was 36 fmol (S/N = 3) and linearity was proven for greater than 2 orders of magnitude, from 45 fmol to 9 pmol for an injection volume of 60 nl. The detectability was limited by the high background noise produced by the post-column derivatization system. The utility of the system was demonstrated for the analysis of methionine enkephalin and its potential oxidation products, using leucine enkephalin as a suitable internal standard.

Chromatography, Liquid↗

PubMedDate not supplied

Relationship of endomysial antibodies to jejunal mucosal pathology: specificity towards both symptomatic and asymptomatic celiacs.

Serum immunoglobulin A class antibodies reactive to the endomysial lining of the smooth muscle bundles of the gastrointestinal tract have recently been reported to be specific and sensitive indicators of celiac disease (CD). A total of 203 subjects were examined for serum endomysial antibodies (EmA) and in 103 small bowel biopsies were obtained. EmA were detected in 43 cases including 26 CD patients evaluated during the gluten challenge phase of diagnosis by European Society for Pediatric Gastroenterology and Nutrition criteria, 11 of 53 symptomatic patients, and 6 asymptomatic family members. All patients with detectable antibody at the time of biopsy exhibited grade III-IV villous atrophy. Disaccharidase activities performed in 19 cases revealed severe deficiencies. EmA were not detected in 160 subjects including 42 infants and children with chronic nonspecific diarrhea. Eighteen of these possessed grade II-III villous atrophy with moderate disaccharidase deficiency and 24 were found to have normal histology and enzymes. The EmA were also not detected in 3 CD patients who were well maintained on a gluten-free diet for greater than 1 year and 25 asymptomatic family members exhibiting normal histology and enzymes. An additional 90 infants and children with other gastrointestinal and liver diseases were also negative for the serum EmA. Fourteen of these patients underwent biopsies and were demonstrated to have normal histology.

Adolescent↗

PubMedDate not supplied

Effects of parenteral nutrition on whole body and extremity composition in children and adolescents with active inflammatory bowel disease.

The effect of parenteral nutrition (PN), combined with corticosteroid therapy, on body composition was evaluated in 22 pediatric patients with active and complicated inflammatory bowel disease (IBD). The patients were divided into two groups according to the duration of PN. Group A consisted of 14 patients who received PN for an average of 43 days (short term) whereas eight patients received PN for an average of 104 days (long term); group B. Nutritional assessments were performed before and following the PN periods. In addition, a follow-up assessment was performed 50 days after the cessation of PN for group A. Serial evaluations included; weight, height, disease activity score, arm anthropometry, subscapular skinfold (SSSF) thickness, 24-hr urinary creatinine, and computed tomography (CT) scan of the thigh. Following PN with a glucose-fat mixture used as a nonprotein energy source, there were significant (p less than 0.05) increases in weight, SSSF, and muscle mass (MM) in both groups. Disease activity declined in both groups and height increased in group B and at the follow-up assessment for group A. Considering extremity composition, both groups exhibited increases in midarm muscle area, midarm fat area, thigh muscle area, and thigh fat area. However, a differential distribution of incremental change was observed depending on the duration of PN. Fat deposition predominated in both the upper and lower extremities for group A. Group B patients, however, although showing a predominance of fat accumulation in the upper extremities, gained muscle and fat components equally in the lower extremities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Catheter-related complications in 35 children and adolescents with gastrointestinal disease on home parenteral nutrition.

A 7-year experience with home parenteral nutrition (HPN) in 35 children and adolescents suffering from severe gastrointestinal diseases is reported. The average duration of HPN was 577 days with a mean of 2.9 catheters per patients. There was a total of 82 episodes of proven catheter-related sepsis, an average of 1.5 septic episodes per patient year. In about half of these instances, the catheter had to be removed. Coagulase-negative and -positive staphylococci were the most common organisms isolated. All four Candida infections led to removal of the catheter. Children requiring HPN from early infancy had a higher frequency of catheter-related infections than those started on HPN after the first year of life. In four cases, clinically significant thrombotic complications occurred. The results suggest that even under optimal conditions of catheter placement and with extensive education in aseptic catheter handling, infection is still relatively common in children receiving HPN. However, there was no mortality related to this complication.

Adolescent↗