PubMed Health⌕ Search

Biomedical subjects

M A López-Boado

Publications and source records attributed to M A López-Boado.

29 records · Page 2Linked to original sources
PubMed1992

[Beneficial effect of oxygen-free radical blockers in experimental kidney transplantation in rats].

UNLABELLED: The clinical potential of free radical (OFR) ablative therapy is dependent upon the proportion of the total injury caused by the reperfusion mechanism compared with the proportion resulting from ischemic injury itself. Prostaglandin cascade can both activate and be activated by OFR. AIM: to investigate the influence of different periods of cold ischemis in renal tissue (cortex and medulla) -regarding superoxide dismutase (S.O.D.) activity, the amount of erythrocyte trapping and prostaglandin synthesis. Also, to evaluate the effect of exogenous S.O.D. in the prevention of reperfusion injury. MATERIAL AND METHODS: 48 Lewis male rats (200-250 g) received renal isografts (RTx) preserved in Collins solution at 4 C for different periods: control group (8) non operated; group I (8) immediate RTx; group II (8) 12 hrs; group III (8) 18 hrs; group IV (8) 12 hrs+S.O.D. (13 mg/kg e.v.); group V (8) 18 hrs+S.O.D. (13 mg/kg e.v.). Before reperfusion all recipients received 1 ml of 51-Cr labelled erythrocytes. After 15 min. reperfusion grafts were removed and samples (cortex and medulla) obtained for measuring trapping of erythrocytes. S.O.D. activity and prostaglandins (PGe2, TxB2, 6-Keto-PGF1). RESULTS: A strong correlation was found between the duration of cold ischemia and the amount of trapping both in cortex and in medulla. S.O.D. administration induced a significant drop of trapping. In non-operated rats S.O.D. activity in cortex was two fold medulla content. However, after reperfusion, a significant decrease in cortex was found in all groups. S.O.D. administration raised S.O.D. activity in cortex similar to control values.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Metabolic characteristics in patients with long-term pancreas graft with systemic or portal venous drainage.

Between January 1983 and June 1990, 32 simultaneous pancreas and kidney transplantations were performed at the University of Barcelona. Insulin-secretion was assessed by intravenous glucose tolerance test performed 24h after transplantation and oral glucose tolerance test during the follow-up. Insulin secretion was also studied in seven non-diabetic patients with kidney transplants. Insulin levels in patients with pancreas and kidney transplantations both at the basal level and after glucose stimulation were higher than normal but not different than those observed in patients with kidney transplantation only. Patients with both pancreas and kidney transplantations and kidney transplantation only presented a mild insulin resistance, measured by the glucose/insulin ratio. Insulin levels during the follow-up of a patient with portal venous drainage were similar to those observed in patients with systemic venous drainage. In conclusion, pancreas transplantation allows a long-term maintenance of glucose homeostasis, although coexisting with an insulin resistance, probably related of the immunosuppressive therapy.

Adult↗
PubMed1991

Tissular prostanoid release, phospholipase A2 activity, and lipid peroxidation in pancreas transplantation.

Free radical species have been implicated as important agents in ischemia-reperfusion injury associated to transplantation procedures. This study was carried out to investigate the possible relationship between phospholipase A2 activity (PLA2), lipoperoxidation, and the changes in arachidonic acid metabolism during ischemia reperfusion injury in pancreas transplantation, as well as the effect of a free radical scavenger such as superoxide dismutase on these changes. For this purpose male Lewis rat groups (n = 7) were classified as follows: group I--control; group II--syngenic pancreas transplantation after 15 min preservation in Collins solution at 4 degrees C; group III--syngenic pancreas transplantation after 18 hr preservation in the same conditions; group IV--same as III but with administration of SOD (i.v.) immediately before revascularization in the recipient rat. The results indicate that significant increases in PLA2 activity and lipoperoxide levels occur concomitantly with an increase of thromboxane B2 (TXB2) and 6-keto prostaglandin F1 alpha (6-keto PGF1 alpha) in pancreatic tissue after pancreas transplantation. The counteracting effect of a free radical scavenger such as SOD supports the role of oxygen free radicals (OFR) mediating activation of PLA2 and subsequent formation of eicosanoids in pancreas transplantation.

Animals↗
PubMedDate not supplied

Histopathology of ventilator-associated pneumonia (VAP) and its clinical implications.

Ventilator-associated pneumonia (VAP) is a diffuse polymicrobial and dynamic process, with heterogeneous distribution of lesions, showing different degrees of histological evolution predominating in the dependent lung zones, in which microbiology and histology can be dissociated. This might explain why blind endobronchial techniques to collect respiratory secretions have similar accuracy compared to visually guided samples, explaining the difficulties in validating any methods for its diagnosis. In the clinical setting the association of acute lung injury (ALI) and pneumonia is controversial. However, it is rare to detect diffuse alveolar damage (DAD) in absence of histological signs of pneumonia, probably evidencing that ALI favors the development of pneumonia. Histopathologically, it is difficult to distinguish initial and resolution phases of DAD from pneumonia and vice versa. On the other hand, there is a clear relationship between antimicrobial treatment and the decreased lung bacterial burden which strengthens the importance of distal airway sampling before starting antibiotic therapy.

Animals↗