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Biomedical subjects

A Celada

Publications and source records attributed to A Celada.

At least 91 records · Page 5Linked to original sources
PubMed1982

Iron overload in a non-transfused patient with thalassaemia intermedia.

A patient with thalassemia intermedia and haemosiderosis is reported. This patient did not receive transfusions or iron therapy. The iron absorption and the plasma iron turnover (PIT) were increased. Transfusions were carried out in order to decrease the amount of abnormal erythropoiesis. After that, the erythropoietin and PIT were decreased to normal levels and the iron absorption also returned to normal. The data presented suggest that increased erythropoiesis was responsible for the abnormally high iron absorption and subsequently for the haemosiderosis of the patient presented.

Blood Transfusion↗
PubMed1982

Basis of plasma iron exchange in the rabbit.

Rabbit transferrin in vitro is shown to load ferrous iron at random on its specific binding sites. The release of iron to reticulocytes is shown to be an all-or-none phenomenon. The two monoferric transferrins have similar in vivo plasma iron clearance rates and tissue distribution. Diferric transferrin, while giving a similar tissue distribution of radioiron, has a plasma iron clearance rate approximately twice that of the monoferric transferrins at low plasma iron concentrations. This difference diminishes as the plasma iron concentration increases. These results are consistent with a progressively greater in vivo conversion of mono- to diferric transferrin as transferrin saturation increases. The in vivo plasma iron turnover in the rabbit increases progressively as the plasma iron increases, from a mean value of approximately 0.8 mg/dl whole blood per d at a plasma iron concentration of 50 mug/dl to 2.0 at a plasma iron concentration of 300. The molecular behavior of transferrin and its iron over this range was investigated using (125)I-transferrin, [(55)Fe]monoferric transferrin, and [(59)Fe]diferric transferrin. The equilibrium distribution of transferrin between its apo-, mono-, and diferric moieties was similar to that predicted on the basis of the percent saturation and random distribution. Rate constants of iron loading and unloading calculated from the percent saturation and from the clearance rates of [(55)Fe]monoferric and [(59)Fe]diferric transferrin were similar to those derived from changes in injected (125)I-apotransferrin. On the basis of these data, it is concluded that the plasma transferrin pool is nonhomogeneous and that the relative size of the mono- and diferric cycles depends on transferrin saturation. A formula is proposed for correcting the plasma iron turnover, thereby eliminating the effect of plasma iron concentration, so as to reflect directly the number of tissue transferrin receptors.

Animals↗
PubMed1982

Ferritin levels and circulating immune complexes in patients with solid tumors.

The level of ferritin and circulating immune complexes (IC) were measured in 53 patients with solid tumors and metastasis using C1q binding assay and the conglutinin binding assay. The level of circulating IC was increased in patients (p less than 0.001) as compared to the controls. Ferritin level was increased in both male and female patients (p less than 0.001), even when the ferritin value was corrected by the aspartic transaminase value, to take for hepatic damage in account. Ferritin was not found to be an important component of immune complexes as IC ferritin did not exceed 2 per cent of total serum ferritin in the 10 patients that were investigated. These results suggest that ferritin levels and circulating IC were increased in patients with solid tumors and metastasis, but that these two parameters are not correlated.

Aged↗
PubMed1982

Opsonic activity of human immune serum on in vitro phagocytosis of Plasmodium falciparum infected red blood cells by monocytes.

In vitro human monocytes from normal blood donors ingest red blood cells infected with Plasmodium falciparum more efficiently than normal red blood cells (NRBC). The phagocytic activity of human monocytes for infected red blood cells (IRBC) is greatly enhanced by the addition of immune sera obtained from individuals living in areas with endemic malaria. In contrast, the addition of sera obtained from individuals recovering from a first infection, or pooled normal sera, does not result in increased phagocytosis of IRBC. The phagocytosis enhancing activity of immune sera is associated with the IgG fraction and IgG depleted sera do not stimulate phagocytosis. Enhanced immune serum mediated phagocytosis occurs as a result of opsonization of IRBC. This was demonstrated by experiments in which monocytes or IRBC were preincubated with immune serum prior to the phagocytic assay. The opsonic activity could be absorbed by IRBC but not by NRBC. The opsonization of IRBC and subsequent phagocytosis were also dependent on the stage of development of the intracellular parasite. IRBC containing schizonts and trophozoites were preferentially phagocytosed as compared with ring forms. The role of malaria induced surface alterations and/or malaria surface antigens in the opsonization of IRBC by immune sera is discussed. These experiments suggest that phagocytosis of P. falciparum IRBC by monocytes may play a role in the immune elimination of malaria infection in humans.

Erythrocytes↗
PubMed1982

No correlation between iron concentration in breast milk and maternal iron stores.

The relation between the iron transmitted to infants by breast milk and the maternal iron stores was investigated in a group of 46 women. Total milk iron concentration was not correlated with the levels of serum ferritin or transferrin saturation. These results suggest that the iron transport from mother to the milk is irrespective to the maternal iron stores.

Adult↗
PubMed1982

Maternal and cord blood ferritin.

The levels of plasma iron, transferrin saturation and ferritin in cord blood of 64 newborns were found to be elevated relative to the corresponding maternal blood. There was no correlation between the levels of plasma iron, transferrin saturation or ferritin in cord and maternal blood. No correlation was found in cord blood between the hemoglobin levels or red cell indices (MCV, MCH and MCHC) with the levels of ferritin. These results suggest that there is an active process of transfer for iron from mother to the fetus, and this transport is independent of fetal erythropoiesis.

Female↗
PubMed1981

[Evaluation of 2 methods for detecting anti-DNA antibodies in collagen disease].

An immunofluorescent technique using Crithidia luciliae (CL) has been developed to detect antibodies against native DNA, type them and determine their complement-fixing capacity. CL possess a kinetoplast containing double-stranded DNA that is not bound to histones: they are therefore a substrate well suited to the determination of antibodies against native DNA. When compared with a radioimmunoassay the technique displayed the same specificity and sensitivity. However, the correlation between clinical symptoms of SLE and anti-DNA antibody titer was better with the CL method than with radioimmunoassay. Determination of complement-fixing capacity and the type of immunoglobulins did not provide useful information. The CL method proved to be reliable, rapid and cheap.

Adult↗
PubMed1981

Clinical evaluation of simultaneously administered 58Co labelled vitamin B12 and 57Co labelled vitamin B12 bound to intrinsic factor in patients with pernicious anaemia.

The clinical and laboratory data from 75 patients with altered vitamin B 12 absorption were reviewed. In 36 cases the diagnosis of pernicious anaemia had been established. Of these, 14 patients showed malabsorption of radiolabelled vitamin B 12, but the absorption of vitamin B 12 bound to the intrinsic factor (IF) was normal (Group A). The other 22 patients with pernicious anaemia showed altered free and IF-bound vitamin B 12 absorption (Group B). Laboratory and clinical data and the absorption tests (xylose and fat excretion) were more abnormal in group B than in group A. Finally, 39 patients (Group C) with general malabsorption showed alternation of the absorption of free and IF-bound vitamin B 12 (Group C). The clinical nd biological data were different in these patients from that found in groups A and B. It is possible that in patients with pernicious anaemia who are untreated an alteration of the intestinal mucosa may produce a malabsorption of vitamin B 12 even in the presence of intrinsic factor.

Anemia, Pernicious↗
PubMed1981

Levels of serum ferritin, folate, and vitamin B12 in pregnant women at term who had been supplemented with iron and folate.

The levels of serum ferritin, folates, and vitamin B12 in relation to the hematologic values were measured in 66 pregnant women at term who had been supplemented with iron (100 mg/day) and folate (350 microgram/day). The levels of hemoglobin in pregnant women were similar to the controls;' however, levels of ferritin and transferrin saturation were decreased and showed a correlation with the hemoglobin. The MCV increased, whereas folate and vitamin B12 decreased, but no correlation was found between these values. These results suggest that in pregnant women (a) serum ferritin and transferrin saturation reflect the iron available for erythropoiesis, (b) the iron supplementation of 100 mg/day in the population studied is not sufficient, and (c) the macrocytosis is independent of the folate and vitamin B12 levels.

Adolescent↗
PubMed1980

Biological variation in free serum hydroxyproline concentration.

Improvements in the accuracy of single estimations of biochemical constituents such as the serum free hydroxyproline (FSHP) concentration can only result from control of biological variation as well as analytical variation. In this context two experiments were carried out to determine whether a significant diurnal rhythm in FSHP concentration exists in man, and whether a worthwhile reduction in intra-individual variance can be achieved by eliminating dietary sources of hydroxyproline. A significant (p < 0.001) diurnal variation in FSHP concentration was detected in a group of normal subjects, with a range of about 20% of the mean. In a second group of eight normal subjects, there was a substantial reduction in the within-subject variation after the start of dietary control. For the most precise determination of FSHP concentration therefore, dietary hydroxyproline sources must be controlled, preferably eliminated, and blood should be sampled at a standardised time of day.

Adult↗
PubMed1980

Separation of granulocytes from peripheral blood in a single step using discontinuous density gradients of Ficoll-Urografin. A comparative study with separation by dextran.

A single-step method for separating granulocytes from peripheral blood using two different gradients of Ficoll-Urografin (F-U) density 1.075 and 1.097 g/ml) is described. The morphological, cytochemical and ultrastructural properties of neutrophils isolated by this method were compared to those isolated by dextran-enhanced sedimentation and neutrophils from the peripheral blood. These studies indicated fewer alterations in neutrophils separated by F-U centrifugation than in neutrophils concentrated by dextran. Finally, the granulocyte layer recovered by F-U fractionation was 98% pure (dextran 71%) and yielded 64% (dextran 79%) of total granulocytes.

Adult↗
PubMed1980

Liver iron storage in Spanish aging population.

Liver samples were collected at autopsy from 70 aged (33 males and 37 females) and 22 young (13 males and nine females) individuals. The liver iron stores of young males (327.00 +/- 50.57 micrograms/g) (mean +/- SEM) are higher than young females (143.48 +/- 32.94 micrograms/g; P < 0.02). There is no difference between the values found for old males (301.72 +/- 31.70 microgram/g) and old females (258.61 +/- 24.14 micrograms/g) or between young and old males. The incidence of low iron stores (less than 50 microgram/g) in males and females of the aged group is similar to that found in the group of young males. It is concluded that in the aged Spanish population studied iron stores are not diminished.

Adult↗