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Biomedical subjects

R Ottaviano

Publications and source records attributed to R Ottaviano.

10 recordsLinked to original sources
PubMed1985

[Microbiological study of 386 strains of Pseudomonas aeruginosa isolated in a 30-month span in the Isernia area with special reference to an antimicrobial assay carried out with the ABAC system on 214 of them].

386 strains of Pseudomonas aeruginosa isolated in the "F. Veneziale" Hospital Laboratory and Public Health Laboratory in Isernia (Italy) from April 1982 to September 1984 were examined by serological typing according to Habs scheme. Susceptibility to 16 antibiotics was evaluated for 214 of them with the ABAC system. Strains from hospitalized patients were also considered for isolation site and hospital service. Among the 14 different serotypes isolated the O12 serotype ranked first accounting for 31.6% of all isolates. Only 25 strains were untypable (6.5%). Tobramycin resulted the most effective antibiotic in inhibiting Ps. aeruginosa in vitro. No clear relationship was found between serotypes and antibiotic susceptibility patterns. Hospital strains showed marked antibiotic resistance compared to community strains from both patients and healthy carriers. Temporal analysis of antibiograms revealed an increasing incidence of resistant Ps. aeruginosa over time. The spread of antibiotic resistance, however, involved mainly hospital strains and was confined to aminoglycosides and anti-Pseudomonas beta-lactam agents.

Anti-Bacterial Agents↗
PubMed1982

alpha-Naphthylthiourea produces dose-dependent lung vascular injury in sheep.

We tested the effects of alpha-naphthylthiourea (ANTU) on lung fluid balance and prostanoid concentrations in anesthetized sheep acutely prepared for collection of pulmonary lymph. Sheep were given 20, 50, 75, or 100 mg/kg ANTU or the vehicle dimethylsulfoxide (DMSO) intravenously. The first phase of the response consisted of transient increases in pulmonary artery pressure and plasma and lymph thromboxane B2 concentrations. Lymph flow increased with no change in the lymph-to-plasma protein concentration ratio (L/P). These changes occurred in sheep given DMSO alone or DMSO with ANTU; they were not dependent on the dose of ANTU given. Two to 4 h after drug administration, pulmonary artery pressure and thromboxane concentrations were normal or near normal. Lymph flow rate reached steady-state levels averaging 1.5 (DMSO alone) to 5.3 (100 mg/kg ANTU) times base line with L/P ratios unchanged from base line. ANTU/DMSO produces transient, severe pulmonary hypertension that may be prostaglandin mediated. The sustained response consists of increased flow rate of protein-rich lymph.

Animals↗
PubMed1979

Fibrinogen clearance from the pulmonary interstitium.

Previous experiments demonstrated that 125I-human fibrinogen (125-RIF) instilled into the distal airway of the right lower lobe in intact dogs passed through the microairway into the interstitium. This report analyzed the subsequent interstitial clearance of this fibrinogen by analyzing plasma and lymph samples for 125I activity. This activity was separated into clottable, and trichloroacetic acid (TCA) insoluble and soluble components. Clottable and TCA-insoluble 125-RIF in the same ratio appeared in lymph from the right lymphatic duct (RD) and thoracic duct (TD). From standard mixing equations we calculate that 1.4 times as much lymph from the right lower lobe flows into the TD as into the RD. With one exception, clottable 125-RIF appeared in plasma only in the absence of an RD; this suggested the presence of accessory lymphatico-venous communications rather than back flux of 125-RIF at the capillary wall. By injecting 131I-human fibrinogen intravenously, we observed a small reduction in clottability (maximum of 10%) in lymph both from the RD and TD. Equilibration in RD lymph was only 1/5 as fast as albumin, and from the measured equilibration rate constant, and the assumption that interstitial fibrinogen clearance is entirely convective, we estimate that the pulmonary interstitial distribution volume for fibrinogen is 70% that for albumin. Non dialyzable 125-RIF products generated in the distal airway adhered to intracapillary, circulating erythrocytes. These products retained fibrinogen antigenicity, and appeared to be further degraded in the vascular compartment.

Animals↗
PubMed1978

Fibrinogen clearance from alveoli.

In experiments lasting 311 +/- 8 (SE) min, we studied the clearance of 125I-fibrinogen ([125I])RIF) from distal lung units of anesthetized, ventilated dogs. We instilled varying concentrations of isosmolar, citrated [125I]RIF ranging from 0.75 to 4 mg/ml into alveoli of individual dogs, and we monitored clearance by the use of external detectors and blood and lymph sampling. Approximately 9% [125I]RIF passed into proximal airways according to detector signal analysis. Excluding airway flow, whole lung clearance of [125I]RIF occurred by degradation to small molecules that rapidly became evenly distributed in body extracellular water. The degradation appeared to take place within the distal airway and not within the lung interstitium because 131I-fibrinogen, injected intravenously, was degraded less in passing from plasma to right duct lymph. The intra-alveolar kinetics of [125I]RIF had 1.5 reaction order with a specific rate of 1.27 X 10(-5) ml(3/2)-mg(-1/2)-min(-1). The data indicate that fibrinogen clearance from alveoli occurs by both transbronchial bulk flow and intraalveolar degradation.

Animals↗
PubMed1977

Albumin clearance from alveoli: tissue permeation vs. airway displacement.

In anesthetized, ventilated dogs, clearance of 2 +/- 0.2 ml alveolar-instilled 1% isosmolar [125I]albumin ([125I]RISA) was separated into bulk airway displacement and transalveolar tissue permeation by the use of collimated external detectors and by sampling of blood and lymph. The detectors were positioned perpendicular to the plane of bronchial drainage, and collimator resolution was characterized by a 50% decrease in count rate for a 5-mm lateral (transbronchial) instillate shift. Detector signals demonstrated no airway shift in 10 dogs studied, the signal decay equaling [125I]RISA absorption determined by lung homogenates. The mean rate constants of [125I]RISA lung clearance and epithelial permeation were 4.08 X 10(-4)-min-1 and 5.48 X 10(-4)-min-1, respectively. The diffusional permeability coefficient of alveolar epithelium for albumin was 4.06 X 10(-9) CM-S-1. Absorbed [125I]RISA was separated into blood and lymph components by collecting lymph from the right lymphatic duct (RLD) and thoracic duct. Mean blood/lymph removal ratio was 6.3/1, and correlated with plasma/RLD lymph steady-state albumin concentration ratios in individual animals. Over a mean observation period of 5.4 h, an average of 12.3% [125I]RISA was cleared from the instilled region. The data suggest that this amount was cleared by permeation; there was little evidence of airway clearance.

Animals↗