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Biomedical subjects

F Roman

Publications and source records attributed to F Roman.

64 records · Page 4Linked to original sources
PubMed1980

Iron mobilization from ferritin by chelating agents.

The release of iron from horse spleen ferritin by the chelating agents desferrioxamine B, rhodotorulic acid, 2,3-dihydroxybenzoate, 2,2'-bipyridyl and pyridine-2-aldehyde-2-pyridyl hydrazone (Paphy) has been studied in vitro. Ferritin prepared by classical procedures involving thermal denaturation releases its iron less effectively than ferritin isolated by a modified procedure that avoids this step. Desferrioxamine B and rhodotorulic acid are the most effective in releasing iron from both preparations of ferritin. When FMN is added, iron release by desferrioxamine B, rhodotorulic acid, and 2,3-dihydroxybenzoate was effectively blocked, whereas both bipyridyl and Paphy showed a marked simulation. A substantial increase in iron release was also observed for bipyridyl and Paphy with ascorbate; a less important increase was noted for rhodotorulic acid. EDTA exerted a marked inhibition of iron release from ferritin with rhodotorulic acid, 2,3-dihydroxybenzoate, bipyridyl, and Paphy. The effects of citrate and oxalate on iron release by the chelators was small. The effect of the concentration of flavin on iron release from ferritin by bipyridyl and desferrioxamine B have been studied. Desferrioxamine is unable to mobilize FeII from ferritin following reduction by reduced FMN, whereas bipyridyl can rapidly complex the ferrous iron. The results are discussed in the context of our current concepts of storage iron mobilization in the treatment of iron overload.

Animals↗
PubMed1979

[Aneurysmectomy and aortocoronary bypass. Immediate and long-term results of 56 patients].

56 pts. who underwent left ventricular aneurismectomy were studied. Clinical improvement and lat post-operatory mortality rate have been evaluated. 39 pts. (II group) also had aortocoronary bypass and other surgical procedures performed at the time of the aneurismectomy. Group I (no other surgery beside the aneurismectomy) and group II did not significant differences in the pre-operatory period and were, therefore, comparable. The total operatory mortality has been of 14% (17.6% in group I and 12.8% in group II). By using myocardial protection the mortality dropped to 5.8%. A significant difference between deceased and survived pts. was noted in the following parameters: cardiac index, A-V oxygen difference, extracorporeal circulation time and the number of diseased coronary arteries (P < 0.001-0.005). Only 2 pts., both in group II, had a late death. After the operation 32 pts. became asymptomatic. Five pts. remained symptomatic: 3 continued to complain of angina and 2 to show signs of left ventricular failure; ventricular arrhythmias were still present in 6 pts. post-operatively (compared to 16 pts. pre-op.). The data suggested that aneurismectomy, associated with aorto-coronary bypass and myocardial protection, has an acceptable operatory risk, particulary in pts. with a good residual ventricular function. Except for ventricular arrhythmias clinical results are very good and late mortality rate is low

Adult↗
PubMedDate not supplied

Sex differences, activation level, and bilateral electrodermal activity.

The effects of the activation level and subject's sex on bilateral skin conductance measures were studied. Thirty right-handed subjects (15 males and 15 females) were exposed to three types of stimulus conditions: rest-period, verbal task and spatial task. Results showed that no relationship was observed between EDA asymmetry and the increase in the activation level induced by the verbal and the spatial tasks. Males showed both higher SCRs and greater frequency of responses on the left than on the right hand. The direction of electrodermal asymmetry remained constant regardless of the stimulus conditions. It was concluded that sex differences are important in the study of EDA asymmetry and that this asymmetry appeared to depend on peripheral variations.

Adult↗
PubMedDate not supplied

Effects of two ACTH analogs on successive odor discrimination learning in rats.

Olfactory discrimination learning has been shown to provide a powerful tool to investigate the mechanisms involved in the formation, storage and retrieval of information in rodent CNS. In the present study we tested the effects of two ACTH analogs, which were previously reported to influence the processes of learning and memory, on various olfactory learning tasks. The ACTH(4-9) analog HOE 427 produced an apparent increase in storage of olfactory information as shown by the difficulty experienced by the animals to rapidly reverse their behavioral responses to previously learned odors. Similarly, the ACTH (4-9) analog ORG 2766 appears to enhance the storage of olfactory information when administered either before or after the learning trials. These data are consistent with the notion that ACTH and related analogs facilitate performance in a variety of learning tasks. In addition, our results suggest possible mechanisms by which some neuroactive peptides might modulate learning and memory processes in the CNS.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Risk factors for loss of lean body mass after liver transplantation.

BACKGROUND: After liver transplantation there is a fall in lean body mass. AIMS: To determine the risk factors for this fall in lean body mass using univariate and subgroup analyses. PATIENTS AND METHODS: Dual energy X-ray absorptiometry was performed in 36 patients (12 with Child-Pugh Class A, 20 with Class B and 4 with Class C disease) before and up to 24 months after liver transplantation. Univariate and sub-group comparative analyses were performed to assess possible risk factors for the fall in lean body mass post-transplantation. RESULTS: The pre-transplantation serum albumin inversely correlated with the fall lean body mass at 1 month (r = 0.55; p < 0.009) and at 6-9 months (r = 0.51; p < 0.05) post-transplantation. A positive correlation between the fall in lean body mass and: (i) cumulative dose of steroids administered at 2-5 months (r = 0.57; p < 0.05) and (ii) length of hospital stay after transplantation (r = 0.52; p < 0.05) were also observed. Neither the severity or presence of cholestatic liver disease pre-transplant, nor acute cellular rejection post-transplant were risk factors for a fall in lean mass. DISCUSSION: A hypercatabolic state post-transplant (represented by low albumin pre-transplantation), immobility, lack of exercise and steroid induced catabolism of muscle may cause the observed fall in lean mass after liver transplantation. Earlier transplantation of patients with better nutritional status and the use of low dose steroid immunosuppressive regimens may prevent the observed fall in lean body mass after transplantation.

Adult↗
PubMedDate not supplied

[Meningococcal meningitis in Spain (1878-1987). VI. Evolution of the proteic subtypes within the serotypes 2 and 15 of Neisseria meningitidis during the epidemic wave].

We have serotyped 620 strains of Neisseria meningitidis, isolated from patients between 1978-1987. These strains, belonging to serotypes 2 and 15, were the most prevalent ones detected during the last epidemic outbreak in Spain. These strains were analyzed by means of polyacrylamide gel electro-phoresis and monoclonal antibody coagglutination, to differentiate subtypes into type 15 and type 2 complex (2a, 2b and 2c types). The proportion of type 2b strains is quite high in group B, and the proportion of subtypes P1.15 and P1.16 is very similar in the same serogroup. We compared the results with those obtained in other countries in our geographical area.

Bacterial Proteins↗