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Biomedical subjects

P Prato

Publications and source records attributed to P Prato.

At least 19 recordsLinked to original sources

Mitochondria-rich cells in gills and skin of an African lungfish, Protopterus annectens.

We used scanning electron microscopy, the vital dye DASPEI and an antibody to the inner mitochondrial membrane to study the presence and localisation of mitochondria-rich cells in the gills and skin (opercular, dorsal and ventral) of the lungfish Protopterus annectens in its free-swimming conditions and at the beginning of aestivation. In the free-swimming period, the gills were short and thick and the pavement cells were extremely large (30-40 microns). The mitochondria-rich cells, which were distributed in the secondary and primary epithelium, occurred as two morphologically different types, i.e. elongated and oval, similar to the alpha and beta chloride cells of fresh water teleosts. In the skin, only one type of mitochondria-rich cells was found, resembling the alpha chloride cells. All the mitochondria-rich cells distributed in the gills and skin were labelled with anti Ca(2+)-ATPase serum indicating the possible uptake of Ca2+ at freshwater chloride cell level. At the start of aestivation, the skin and gills were covered by a thick layer of mucus and the epithelium of the gills was reduced. The mitochondria-rich cells were almost completely covered by the pavement cells.

Animals↗

Endothelial targeting with C1-inhibitor reduces complement activation in vitro and during ex vivo reperfusion of pig liver.

Tissue damage during cold storage and reperfusion remains a major obstacle to wider use of transplantation. Vascular endothelial cells and complement activation are thought to be involved in the inflammatory reactions following reperfusion, so endothelial targeting of complement inhibitors is of great interest. Using an in vitro model of human umbilical vein endothelial cells (HUVEC) cold storage and an animal model of ex vivo liver reperfusion after cold ischaemia, we assessed the effect of C1-INH on cell functions and liver damage. We found that in vitro C1-INH bound to HUVEC in a manner depending on the duration of cold storage. Cell-bound C1-INH was functionally active since retained the ability to inhibit exogenous C1s. To assess the ability of cell-bound C1-INH to prevent complement activation during organ reperfusion, we added C1-INH to the preservation solution in an animal model of extracorporeal liver reperfusion. Ex vivo liver reperfusion after 8 h of cold ischaemia resulted in plasma C3 activation and reduction of total serum haemolytic activity, and at tissue level deposition of C3 associated with variable level of inflammatory cell infiltration and tissue damage. These findings were reduced when livers were stored in preservation solution containing C1-INH. Immunohistochemical analysis of C1-INH-treated livers showed immunoreactivity localized on the sinusoidal pole of the liver trabeculae, linked to sinusoidal endothelium, so it is likely that the protective effect was due to C1-INH retained by the livers. These results suggest that adding C1-INH to the preservation solution may be useful to reduce complement activation and tissue injury during the reperfusion of an ischaemic liver.

Animals↗

Simulated microgravity induces alteration in the central nervous system.

To investigate whether the signs of neurophysiological impairment observed in flight may be traced back to cytomorphology, we undertook a ground-based study focusing upon the architecture of cultured glial cells under simulated microgravity obtained by three-dimensional clinorotation.

Actin Cytoskeleton↗

Efficacy of intraoperative heat administration by ventilation with warm humidified gases and an oesophageal warming system.

We measured changes in body temperature in 12 hypothermic (mean aural temperature 34.4 (SD 1.0) degrees C) pigs during general anaesthesia with an open abdominal cavity and the effect of two warming systems: heating of inspired gases to 39 degrees C (intratracheal temperature) and oesophageal warming to 39 degrees C by a water perfused oesophageal heat exchanger. Each animal underwent both treatments and the control period in random sequence. Each condition was studied over 1 h. No additional protection against heat loss (drapes, blankets, i.v. fluids warming, etc.) was used. Anaesthesia, room temperature and relative humidity, amount and temperature of infusions and extension of exposed visceral surfaces were standardized. Mean decrease in body temperature was 1.0 (0.7) degree C (P < 0.005) without warming and 0.6 (0.2) degree C (P < 0.005) with heated inspired gases: this difference was not statistically significant. Oesophageal warming was very efficient as mean body temperature did not change significantly (-0.1 (0.2) degree C; ns).

Anesthesia, General↗

Long-term stability of clinical attachment following guided tissue regeneration and conventional therapy.

UNLABELLED: 44 patients (34% smokers) presenting with severe periodontitis were treated with full mouth root planing (RPL). In each patient, 1 intrabony defect was treated with guided tissue regeneration (GTR). After 1 year of monthly prophylaxis, full mouth plaque (FMPS) and bleeding (FMBS) scores were 8.3 +/- 4.1% and 5.6 +/- 3.8%. At 1 year, the GTR treated sites were matched, in each patient, with 1 RPL site, in terms of probing attachment level (PAL 6.8 +/- 2.4 mm GTR, and 6.5 +/- 2.3 mm RPL). At this point, 24 patients took part in a supportive periodontal care program. 20 patients did not participate, and received only sporadic care by general dentists. At 5 years, all patients were reexamined. FMPS was 10.5 +/- 6.8% and FMBS 7.7 +/- 6.4%. A significant PAL loss was observed in both sites (1.2 +/- 1.4 mm GTR, 1.3 +/- 1.3 mm RPL, p < 0.0001) between 1 and 5 years. Differences in PAL loss between GTR and RPL sites were not statistically significant. Only a minority of sites (34%), however, lost PAL, while 66% remained stable. 75% of the matched sites (GTR and RPL) within the same patients were concordant in terms of PAL stability. The 23 patients in which both sites remained stable, had good oral hygiene, complied with the recall system, and did not smoke. The 10 patients in which both sites lost PAL showed deteriorating oral hygiene, did not comply with the recall system, and smoked. PAL loss in the GTR and/or RPL sites was consistently observed in patients (losers) showing PAL loss in other teeth. Losers had, in general, negative subjects characteristics, and showed a higher prevalence of tooth loss. IN CONCLUSION: (i) GTR and RPL sites showed comparable susceptibility to periodontal breakdown; (ii) stability of outcomes was consistently associated with good oral hygiene, compliance with a supportive periodontal care program, and no cigarette smoking.

Adult↗

Acute lung injury from mechanical ventilation at moderately high airway pressures.

We have explored adverse pulmonary effects of mechanical ventilation at a peak inspiratory pressure of 30 cmH2O in paralyzed and anesthetized healthy sheep. A control group of eight sheep (group A) was mechanically ventilated with 40% oxygen at a tidal volume of 10 ml/kg, a frequency of 15 breaths/min, a peak inspiratory pressure less than 18 cmH2O, and a positive end-expiratory pressure of 3-5 cmH2O. During the ensuing 48 h, there were no measurable deleterious changes in lung function or arterial blood gases. Another 19 sheep were ventilated with 40% oxygen at a peak inspiratory pressure of 30 cmH2O under a different set of conditions and were randomly assigned to two groups. In group B, the respiratory rate was kept near 4 breaths/min to keep arterial PCO2 in the normal range; in group C, the frequency was kept near 15 breaths/min by including a variable dead space in the ventilator circuit to keep arterial PCO2 near baseline values. There was a progressive deterioration in total static lung compliance, functional residual capacity, and arterial blood gases. After some hours, there were abnormal chest roentgenographic changes. At time of death we found severe pulmonary atelectasis, increased wet lung weight, and an increase in the minimum surface tension of saline lung lavage fluid.

Air Pressure↗

[Amino acid profile in patients with orthotopic liver transplant].

Plasma amino acids profile is assumed to be a good index of whole body amino acids balance and in particular to give information on the actual control of the transplanted liver on protein metabolism. Variations in plasma amino acids profile were studied in 12 patients undergoing orthotopic liver transplantation. Total parenteral nutrition (TPN) was maintained at 26.05 +/- 1.53 kcal/kg and 0.117 +/- 0.01 gN/kg until the 7th postoperative day. Following this, an enteral nutrition (EN) was added as to maintain a mixed metabolic therapy at 30.28 +/- 2.76 kcal/kg and 0.198 +/- 0.01 gN/kg. Such a treatment completely satisfied the caloric needs, while nitrogen input was prudently kept low in accordance to the lack of data on the metabolic effectiveness of the transplanted liver. Amino acids profiles showed an early metabolic recovery of the new liver. Therefore nitrogen input could be higher and more adequate to nitrogen needs.

Adult↗