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Biomedical subjects

A Olmos

Publications and source records attributed to A Olmos.

67 records · Page 4Linked to original sources

[Porphyrin excretion in normal (author's transl)].

Porphyrin excretion in normal subjects was studied by solvent extraction procedures and by thin-layer chromatography of their methyl-esters. The mean value of the urinary coproporphyrin fraction was significantly higher in males than in females. Taking age also into account this difference was not significant in subjects under 20 years of age. Within the same sex, age did not have any influence on this coproporphyrin fraction. Neither of these two factors, i.e. sex and age modified the mean values of uroporphyrin fraction. Males and females showed similar amounts of fecal copro and protoporphyrin fractions. The thin-layer chromatographic urinary pattern revealed a minor porcentual value of octo-carboxylic-porphyrin in males, due mainly to a lower amount of porphyrin in the 20-40 year, period, when males also showed a decreased value of heptacarboxylic-porphyrin. Neither sex nor age modified the fecal chromatographic porphyrin pattern. Di-carboxylic porphyrins were always predominant, but theri appraisal was very frequently interfered by the presence in feces of fluorescent substances with a Rf similar to tri-carboxylic-porphyrin but with a pheophytinlike spectra.

Adolescent↗

[Study of the causes of death in a hemodialysis unit (author's transl)].

A review is made of the deaths which occurred in a hemodialysis unit between 1969 and 1977. Sixty-two patients were treated during this period, 18 of whom died. The actuarial percentages of survival are also established. The mortality rate was 15.5 percent during the initial period and 31.5 percent after the fourth year. Deaths in the first monts were caused by cardiac and infectious complications. Those occurring at a later period resulted from the lack of good vascular access which is necessary to maintain a good quality of dialysis.

Adolescent↗

Differentiation of Pasteurella haemolytica biotypes A and T with growth inhibitors.

Differentiation of type A and type T cultures of Pasteurella haemolytica was accomplished by paper disks containing 0.3 microgram of penicillin G, which produced zones of inhibition larger than 10 mm with type A but not with type T strains. Basic fuchsin (0.2 microgram/ml), brilliant green (0.005 microgram/ml), methylene blue (3.1 micrograms/ml) in brain heart infusion broth permitted the growth of type T but that of type A isolates.

Animals↗

[Core and cutaneous thermal changes in the upper limb after anesthesia induction].

OBJECTIVES: To describe and compare the core-cutaneous thermal and photoplethysmographic time-course effects after induction of general anesthesia with propofol, fentanyl and vecuronium. PATIENTS AND METHODS: We measured digital blood flow, core temperature and skin temperature in the upper limb (fingertip, forearm and upper arm) in 20 patients (10 men and 10 women, ASA-I) before anesthetic induction and 5, 10, 15 and 20 min after induction. Skin temperature changes were recorded with disposable thermocouples. Blood flow was recorded by digital photoplethysmography (PhPl) in the thumb. Anesthesia was provided without premedication, using propofol (3 mg.kg-1), fentanyl (0.1 mg) and vecuronium (0.1 mg.kg-1). After endotracheal intubation, anesthesia was maintained with oxygen-nitrous oxide and 0.1 mg of intravenous fentanyl at the tenth minute, without inhaled anesthetics. RESULTS: All patients showed intense, abrupt vasodilatation in the thumb with marked increases in PhPl (PhPl = 10.4 +/- 5.0 mV/V, at 5 min, p < 0.001) and fingertip temperature (TFingertip = 6.2 +/- 2.0 C, at 10 min, p < 0.001). However, skin temperature changes in the upper arm and forearm were moderate and slower (TForearm = 2.1 +/- 1.4 C, p < 0.01 and TUpper arm = 1.1 +/- 1.2 C, p < 0.01; at 20 min in both cases). A significant correlation was found only between PhPl and TFingertip (r = 0.55, p < 0.001). CONCLUSIONS: Anesthetic induction with propofol, fentanyl and vecuronium produces cutaneous vasodilatation in the upper limb unequally: the greatest increase in skin temperature occurs at the fingertip, while forearm and upper arm temperatures increase less. We think that skin vasodilatation in peripheral distal areas may play an important role in redistributing core heat during anesthesia.

Anesthesia, Intravenous↗

[Analysis of the survival of permanent vascular access ports].

Complications arising from vascular access are major causes of morbidity in patients on renal replacement therapy. They contribute to frustration of health care providers and to high medical cost. To prevent failures in the future it will be helpful to identify the factors that are related to vascular access, malfunction. In a retrospective analysis we analysed the types, duration and primary patency rate of 1,033 permanent vascular access in 544 consecutive patients established during a 13-year period in a tertiary care hospital. Patient characteristics, incidence and risk factors related to vascular access failure were registered. In addition vascular access outcomes in patients who started haemodialysis with a catheter and in whom initial vascular access failure occurred were analysed separately. Forty-five per cent of patients required a central catheter at the start of HD, but 92% of them were being dialysed with an a-v fistula at the last observation. The total number of complications was 0.24 episodes per patient per year at risk, and the rate of thrombosis 0.1. A total of 52% of patients were dialysed throughout the observation period with their initial a-v fistula; 9.3% had more than three episodes of vascular access failure. The radiocephalic a-v fistula was the access with the best median duration, exceeding 7 years, but also the type that had the highest initial failure rate, i.e. 25% of patients and 13% of events. The brachiocephalic a-v fistula was the second most frequent type of vascular access, with a median duration of function of 3.6 years, in contrast the humerobasilar a-v fistula, lasted on average over 5 years. Average patency of the different types of grafts did not exceed 1 year, with the exception of the autologous saphenous graft with a median duration of function of 1.4 years. Patients with glomerulonephritis had the best function rates for their access, the median duration exceeding the duration of the study, whereas in half of diabetic patients it was less than 1 year. The duration of patency of the vascular access was twice as long in patients below age 65 years and in elderly males compared to elderly females. Patients who start HD with a catheter, as well as those with initial vascular access failure, have a higher rate of access failure in the subsequent course on renal replacement therapy. In conclusion, the radiocephalic and the brachiocephalic a-v fistula are the two types of vascular access with the longest duration of function, although a high rate of initial failure is seen with the radiocephalic a-v fistula. Age, female gender, presence of diabetic nephropathy, start of dialysis with a catheter, and failure to wait for initial maturation of vascular access are risk factors, and account for the majority of vascular access failure during renal replacement therapy.

Adolescent↗