Biomedical subjects

D Magliano

Publications and source records attributed to D Magliano.

3 recordsLinked to original sources

PubMed1998

Rubella virus replication complexes are virus-modified lysosomes.

Replication complexes are membrane-bound cytoplasmic vacuoles involved in rubella virus (RV) replication. These structures can be identified by their characteristic morphology at the electron microscopy (EM) level and by their association with double-stranded (ds) RNA in immunogold labeling EM studies. Although these virus-induced structures bear some resemblance to lysosomes, their exact nature and origin are unknown. In this study, the localization of two lysosomal markers, lysosomal-associated membrane protein (Lamp-1) and acid phosphatase, relative to the replication complexes was examined by light and electron microscopy. Confocal microscopy using antibodies to dsRNA and Lamp-1 showed colocalization of these two markers in the cytoplasm of RV-infected cells. Immunogold labeling EM studies using antibodies to Lamp-1 confirmed that Lamp-1 was associated with RV replication complexes. EM histochemical studies demonstrated the presence of acid phosphatase in the vacuoles of RV replication complexes. Taken together, these studies show that RV replication complexes are virus-modified lysosomes.

Acid Phosphatase↗

PubMed1996

Effects of U-74389G, a novel 21-aminosteroid, on small intestinal ischemia and reperfusion injury in horses.

OBJECTIVE: To determine the effects of the 21-aminosteroid, U-74389G, on reperfusion of the equine jejunum, using total (TVO) and partial (PVO) vascular occlusion during the ischemic period. DESIGN: TVO: 16 healthy horses were randomly allotted to 3 groups-4 horses received the vehicle alone, 6 horses received a low dosage (3 mg/kg o body weight), and 6 horses a high dosage (10 mg/kg) of U-7438G. PVO: 10 healthy horses were randomly allotted to 2 groups--5 horses received the vehicle alone, and 5 horses received the low dosage (3 mg/kg) of U-74389G. PROCEDURES: TVO was induced for 1 hour followed by 2 hours of reperfusion. During PVO, blood flow was reduced to 20% of baseline for 2 hours, followed by 2 hours of reperfusion. For both models, either the vehicle alone or the drug was given 15 minutes prior to reperfusion. Samples were obtained before, during, and after ischemia for determination of myeloperoxidase (MPO) activity, malondealdehyde (MDA) concentration, concentration of conjugated dienes (PVO experiment only), and morphometric analysis. RESULTS: TVO: tissue concentration of MDA and MPO activity were not altered in any group by ischemia or reperfusion. During ischemia, mucosal volume and surface area were reduced. After reperfusion, no further reduction occurred. After initial decrease in submucosal volume during ischemia, there was a significant increase after reperfusion in the vehicle-only group (P < 0.05). PVO: there were no alterations in the concentration of either MDA or conjugated dienes. There was significant increase in the activity of MPO during ischemia and reperfusion (P < 0.05). These effects were similar for the vehicle-only and drug groups. During ischemia, there was a significant decrease in mucosal surface area and volume (P < 0.05), that was continued during reperfusion for the vehicle-only (P < 0.05). Submucosal volume increased during ischemia and reperfusion. CONCLUSIONS AND CLINICAL RELEVANCE: Reduced blood flow during ischemia (PVO group) caused continued loss in mucosal volume and surface area during reperfusion. At the dosage given, the 21-aminosteroid, U-74389G, was not effective in preventing continued reduction in mucosal volume and surface area after restoration of blood supply in the horses subjected to reduced blood flow.

Animals↗

PubMed1993

Effects of the 21-aminosteroid U-74389G on ischemia and reperfusion injury of the ascending colon in horses.

Sixteen horses were allotted at random to 3 groups: vehicle only; low dosage (vehicle and 3 mg of U-74389G/kg of body weight); high dosage (vehicle and 10 mg of U-74389G/kg). These solutions were given prior to reperfusion. The ascending colon was subjected to 2 hours of ischemia followed by 2 hours of reperfusion. Before, during, and after ischemia, full-thickness colonic tissue biopsy specimens were obtained for measurement of malondealdehyde (MDA) concentration and myeloperoxidase activity and for morphologic evaluation. Although increases were not significant, MDA concentration and myeloperoxidase activity increased during ischemia and reperfusion. Administration of U-74389G did not have significant effects on MDA concentration and myeloperoxidase activity. However, the lower dosage tended (P = 0.08) to reduce myeloperoxidase activity at 30 and 60 minutes of reperfusion. In horses of the vehicle-only group, ischemia induced a decrease in mucosal surface area that was continued into the reperfusion period (P < or = 0.05). Administration of U-74389G at both dosages (3 and 10 mg/kg) prevented the reperfusion-induced reduction in mucosal surface area, which was significant at 60 minutes (high dosage; P = 0.05) and 90 minutes (low and high dosages; P = 0.02). After initial reduction in horses of all groups, mucosal volume increased for the initial 60 minutes of reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗