Magnetic characterisation of rat muscle tissues after subcutaneous iron dextran injection

Ex vivo freeze-dried rat muscle tissues, collected at different times t after a single dose of subcutaneously injected iron dextran, have been magnetically characterised. The AC susceptibility of the tissues shows an overall superparamagnetic behaviour and the dependence on t of, especially, the out-of-phase component is remarkably systematic despite the fact that each tissue originates in a different rat individual. The experiments show that the akaganéite (beta-FeOOH) nanoparticles contained in the injected drug are progressively degraded in the living tissue and, at times of the order of 1 month and for all the analysed rat individuals, converge to a magnetically well-defined species with much narrower magnetic activation energy distribution than iron dextran. Thorough transmission electron microscopy experiments of the same tissues indicate the presence of oxyhydroxide particles, whose size decreases for increasing t in agreement with the interpretation of the magnetic susceptibility. The conclusions drawn from the magnetic study do well correspond to the properties of the whole tissue since no biochemical extraction work has been done. The AC susceptibility appears to be a valuable and complementary tool in pharmacological studies of iron-containing drugs.

[Effects of levofolinic acid on plasma homocysteine concentrations in healthy and young women in preconceptional care]

BACKGROUND

Increases in total plasmatic homocysteine (tHcy) represents a risk factor for neural tube defects. We studied the effects of levofolinic acid (l,5-formyl-tetrahydrofolic) on the plasmatic tHcylevels in women of child-bearing age.

MATERIALS AND METHOD

Healthy women aged 18-35 years (n = 30) received levofolinic acid, 5 mg/day,orally for 30 days. Both tHcy and intraerythrocytic folate levels were measured before treatment (day 0), on days 2, 5, 10 and 30 within the treatment period and on days 30 (day 60) and 60 (day 90) after the treatment was finished. Plasmatic tHcy was measured by fluorescence polarisation immunoassay and intraerythrocyticfolates by chemiluminescent immunoassay.

RESULTS

Plasmatic tHcy decreased from the second day of treatment onwards (day 0 vs. 2: mean of difference: -1.24 micromol/l; CI 95% = -0.84 to -1.63; p < 0.001). The maximum decline (32.3%) was observed after 30 days (mean of difference = -2.72 micromol/l; CI 95% = -2.20 to -3.24; p < 0.001).After finishing the treatment, the hypohomocysteinic effect persisted up to days 60 (mean of difference = -2.67 micromol/l; CI 95% = -2.07 to -3.26; p < 0.001)and 90 (mean of difference = -1.49 micromol/l; CI 95% = -0.94 to -2.03; p < 0.001). The response was greater when the plasmatic tHcy concentration was >= 9 micromol/l.

CONCLUSIONS

Levofolinic acid leads to a earlier, intense and persistent drop of the plasmatictHcy levels.

[Fibrinolytic system in patients with myocardial infarction and other coronary disease risk factors]

PURPOSE

To evaluate the fibrinolytic system function in survivors of acute myocardial infarction (AMI) and to appreciate the differences between patients with history of diabetes and/or dyslipaemia and those without such history.

PATIENTS AND METHODS

A series comprised of 101 patients (83 men and 18 women) surviving six months after AMI and with mean age of 61.7 +/- 8.5 years was studied. Previous history of type II diabetes mellitus was present in 22 cases, while 42 others had some type of dyslipaemia (16, hypertriglyceridaemia; 15, hypercholesterolaemia; 11 both). Of the patients with diabetes mellitus, 14 had also dyslipaemia (5, hypertriglyceridaemia; 6, hypercholesterolaemia; 3, both conditions). The rates of plasminogen-activator inhibitor (PAI-1), fibrinogen, plasminogen, and alpha-2-antiplasmin, along with the venous occlusion test to determine tissular plasminogen activator (t-PA), both functional and antigenic, before and after venous occlusion, were tested in all cases. The studies were performed at the moment of AMI and 6 months later.

RESULTS

PAI-1 concentration during AMI in the patients with some concurrent lipid anomaly showed significant differences with respect to the patients without any such associated disease (p < 0.001). The patients with history of dyslipaemia had significant increase of PAI-1 (p < 0.001) with respect to those without such history. Those patients with associated diabetes showed significantly increased PAI-1 concentration with regard to those without it, both in the acute phase and 6 months later (p < 0.05); significant increase was also found when comparing the patients with diabetes and dyslipaemia with those ones with only diabetes or dyslipaemia (p < 0.05). A significant increase of PAI-1 level (p < 0.001) was found in the 6-month study in the dyslipaemia patients with respect to non-dyslipaemic, and similar findings appeared with respect to diabetics and non-diabetics (p < 0.05). The 14 patients with both disorders showed increased values when compared with those having only one associated impairment (p < 0.05). When comparing the PAI-1 rates at AMI and 6 months later in the patients with dyslipaemia or diabetes, statistically significant decrease could be noted (p < 0.05 and p < 0.01, respectively). Before venous occlusion, t-PA was significantly increased in diabetic or dyslipaemic patients (p < 0.05) and in the patients with both conditions (p < 0.01).

CONCLUSIONS

Patients with AMI and abnormalities of the lipidic or glycaemic metabolism have fibrinolytic dysfunction on the basis of an increase of the main inhibitor of the fibrinolytic system and a decreased release of tissular plasminogen activator. Those patients with both metabolic abnormalities have a deeper fibrinolytic hypofunction, with higher PAI-1 concentration.

The increase in erythrocyte deformability in patients treated with nicardipine or nimodipine

A study was made of a total of 50 patients, 36 females and 14 males, with an average age of 51.3 +/- 11.71 years (range 19-71). The group consisted of outpatients who came to the neurology clinic suffering from vascular headache or other symptomatic complaint of vascular type. In all cases, the existence of an organic neurological pathology had been considered and rejected. All patients who were smokers or suffering from hypertension were excluded, as well as those who had abnormal lipid or glucose values or who were on drug treatment for other reasons. The basal erythrocyte deformability value was determined and the patients divided into two random homogeneous groups. One of the groups was treated with nimodipine (90 mg/d) and the other with nicardipine (60 mg/d) for a period of two months. After this treatment period a further determination of the erythrocyte deformability was carried out. In the group treated with nimodipine, the erythrocyte deformability varied from 45.5 +/- 7.4 mcl/s to 50.35 +/- 12.02 mcl/s (p = 0.07123). In the group treated with nicardipine, these values varied from 45.96 +/- 7.35 mcl/s to 56.21 +/- 12.72 mcl/s (p = 0.00079). It was concluded that in both groups of patients, after two months treatment with these calcium antagonists, there was an improvement in erythrocyte deformability and, therefore, in blood fluidity, although only the nicardipine-treated group reached statistically significant levels.

[Reduction of iron deposits after physical exercise of short-duration]

PURPOSE

To study iron metabolism in young people subjected to short-term physical exertion.

MATERIAL AND METHODS

Haemoglobin rate, plasma iron, total iron binding capacity and haptoglobin were assessed before, during and fifteen days after seven-day intensive exertions (military drill) in 38 cadets of the General Military Academy at Zaragoza, at sea-level altitude. The type and intensity of the exercises and the diet were similar for all the subjects. Mean and standard deviation of all values were calculated; the differences were studied by paired t test and p < 0.005 was fixed to allow statistical differences.

RESULTS

Decreased serum ferritin, which probably means diminished iron deposits, was found after exertions. Haemolysis is not likely involved since the haptoglobin rates were not decreased below the security limits which avoid haemoglobinuria.

CONCLUSIONS

Physical exercise, although of short duration, may lessen iron deposits, although not to the extent of iron-lack erythropoiesis.

[Incidence of iron deficiency in a group of 922 candidates for volunteer blood donation]

Serum ferritin and haemoglobin rate were assessed in 637 men and 285 women, all of them seemingly healthy, who were about to donate blood for the first time. Serum ferritin rates suggesting iron deficiency were found in 1.88% of the men and in 9.47% of the women, anaemia being present in 7.69% of the iron deficiencies. Serum ferritin can be a useful parameter for the detection of latent iron deficiency in blood donors, and it may disclose the group of donors who should receive iron therapy, or should be recommended not to donate blood, without any significant increase on the cost per unit of blood.