Biomedical subjects

Antonio Pusceddu

Publications and source records attributed to Antonio Pusceddu.

3 recordsLinked to original sources

PubMed2005

Sediment resuspension effects on the benthic microbial loop in experimental microcosms.

Sediment resuspension induced by anthropogenic disturbance is becoming a major threat of marine coastal ecosystems worldwide. The effects of sediment resuspension on the pelagic domain and on macro- and meiobenthos are well documented in the literature, whereas the effects on the benthic microbial components are nearly neglected. We have investigated the effects of sediment resuspension at two different disturbance levels on benthic bacterial abundance, biomass, and activities and on heterotrophic nanobenthos abundance in experimental microcosms. The results of our experiments pointed out that, independently from the amount of involved energy, sediment resuspension determined a general decrease of all benthic microbial components. The main effects consisted of a decreased abundance of the metabolically active bacterial fraction and of heterotrophic nanobenthos abundance. However, the amount of energy involved in sediment resuspension had differential effects on the structure and functioning of the benthic microbial loop, but only in the short term (i.e., within 36 h). Sediment resuspension had a stimulatory effect on activities of surviving bacterial cells, which, in turn, resulted in increased sediment organic C turnover rates. We hypothesize that such an effect, enhancing nutrient availability, might have relevant consequences on the trophic state of coastal marine ecosystem.

Aminopeptidases↗

PubMed2005

Response of benthic protozoa and thraustochytrid protists to fish farm impact in seagrass (Posidonia oceanica) and soft-bottom sediments.

We investigated the impact of fish farm biodeposition on benthic bacteria, thraustochytrid protists, and heterotrophic protozoa (nanoflagellates and ciliates) in an oligotrophic area of the Mediterranean Sea. The fish farm impact was investigated both on a seagrass (Posidonia oceanica) bed and on soft bottom sediments. In both systems, sediment samples were collected with a multicontrol sampling strategy (i.e., beneath the fish farm and at three control sites per system). The uneaten food pellets supplied to the fish determined the accumulation of sediment organic matter and the enhancement of protein content in impacted sediments (both seagrass bed and soft sediments). In both systems, the abundance and biomass of heterotrophic protists increased significantly beneath the fish farm, but the structure of the protist assemblages responded differently in vegetated and unvegetated sediments. Thraustochytrid abundance increased significantly in impacted seagrass. These results provide evidence that the structure of protist assemblages respond significantly to fish farm biodeposition and indicate that the monitoring of these benthic components provides complementary information for the assessment of the fish farm impact on the benthic systems.

Alismatales↗

PubMed2002

Frequency of hypotension and bradycardia during general anesthesia, epidural anesthesia, or integrated epidural-general anesthesia for total hip replacement.

STUDY OBJECTIVE: To evaluate the frequency of hypotension and bradycardia during integrated epidural-general anesthesia as compared with general anesthesia or epidural anesthesia alone. DESIGN: Prospective, randomized, open, multicenter study. SETTING: Inpatient anesthesia at 7 University or Hospital Departments of anesthesia. PATIENTS: 210 ASA physical status I, II, and III patients undergoing elective total hip replacement. INTERVENTIONS: Using a balanced randomization method, each hospital enrolled 30 consecutive patients who received integrated epidural-general anesthesia, epidural anesthesia, or general anesthesia. MEASUREMENTS AND MAIN RESULTS: Occurrence of clinically relevant hypotension (systolic arterial blood pressure (BP) decrease >30% from baseline), or bradycardia (heart rate (HR) <45 bpm) requiring pharmacologic treatment were recorded, as well as routine cardiovascular parameters. Clinically relevant hypotension during induction of nerve block was reported in 13 patients receiving epidural block (18%) and 16 patients receiving epidural-general anesthesia (22%) (p = 0.67). Subsequently, 22 of the remaining 54 patients in the epidural-general anesthesia group (41%) developed hypotension after the induction of general anesthesia, as compared with 16 patients of the general anesthesia group (23%) (p = 0.049). No differences in HR or in frequency of bradycardia were observed in the three groups. CONCLUSIONS: The induction of general anesthesia in patients with an epidural block up to T10 increased the odds of developing clinically relevant hypotension as compared with those patients who received no epidural block, and was associated with a twofold increase of the odds of hypotension as compared with the use of epidural anesthesia alone.

Aged↗