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Biomedical subjects

A Foradori

Publications and source records attributed to A Foradori.

At least 19 recordsLinked to original sources
PubMed1991

Platelet 5-hydroxytryptamine increases with platelet age in dogs.

Thrombocytopenia was induced in mongrel dogs by two mechanisms: immunologically, by intravenous injection of heterologous antiplatelet antibody, and non-immunologically, by circulating the blood through glass beads in anesthetized animals. The platelet content of 5-HT was monitored before and during the recovery of the blood platelet counts. This period is associated with the normalization of the mean platelet survival time and with a progressive increase in the mean age of the circulating platelet population. A continuous increment in platelet 5-HT closely followed the increase in platelet counts in both models of thrombocytopenia, and a strong correlation was found between the platelet age and 5-HT content. These findings support the concept that platelets accumulate 5-HT during their physiological aging process, contradicting the notion that a negative balance in 5-HT content results at the end of their physiological lifespan in circulation. These results are not in conflict with the concept that circulating platelets release and re-uptake 5-HT.

Animals↗
PubMed1991

Effect of maternal administration of thyrotropin releasing hormone on the preterm fetal pituitary-thyroid axis.

We evaluated the response of preterm fetuses to maternal intravenous injection of 400 micrograms of thyrotropin releasing hormone (TRH) between 30 minutes and 5 hours before delivery (n = 12). An additional seven mothers received saline solution and served as control subjects. There were no statistically significant differences in gestational age, birth weight, or Apgar scores between groups. At delivery, concentrations of maternal thyrotropin were elevated in the TRH group compared with the control group (12.0 +/- 1.6 vs 5.6 +/- 0.5 mU/L; p less than 0.005); however, maternal triiodothyronine (T3) values remained unchanged. Significant elevations of fetal thyrotropin and T3 were observed after maternal administration of TRH compared with control subjects (45.8 +/- 7.7 vs 8.4 +/- 0.9 mU/L (p less than 0.002) and 1.3 +/- 0.07 vs 0.7 +/- 0.04 nmol/L or 87 +/- 5 vs 49 +/- 3 ng/dl (p less than 0.001), respectively). Fetal thyroxine (T4) and prolactin values were also elevated after exposure to TRH (135 +/- 5 vs 86 +/- 10 nmol/L or 10.5 +/- 0.4 vs 6.7 +/- 0.8 micrograms/dl (p less than 0.001) and 212 +/- 31 vs 105 +/- 28 micrograms/L (p less than 0.05), respectively). Two hours after birth, a significant increase in T3 but not T4 levels was observed in both groups of infants. These data indicate that fetal exposure to a single dose of TRH via maternal administration of this hormone results in marked stimulation of the preterm fetal pituitary-thyroid axis, as in the fetus at term, and that this treatment does not inhibit the early postnatal surge of T3.

Female↗
PubMed1991

A prepubertal surge of thyrotropin precedes an increase in thyroxine and 3,5,3'-triiodothyronine in normal children.

The variations in plasma levels of TSH, T4, T3, and rT3, during the pubertal period, were studied in 647 school students from the urban area of Santiago in Chile (47% males and 53% females) with ages ranging between 7.5 and 15 yr. The subjects were grouped by age in consecutive intervals of 6 months each, and pubertal development was determined in every subject. TSH showed a significant increase, reaching a peak in the 9- to 9.5-yr interval. The same was found for T3 and T4, which reached a peak by 10 and 11 yr. The T4/T3 ratio did not show any significant variation with age. After 9.5 yr, a decrease in rT3 and increase in the T4/rT3 ratio was found. The TSH peak preceded the onset of clinical pubertal development, while the T3 and T4 peaks coincided with this onset. The variations in rT3 suggest an increase of peripheral conversion of T4 to T3. These transient events, not described until now, could be termed thyroidarche and could have a significant effect on pubertal growth and development.

Adolescent↗
PubMed1990

[The effect of anti-insulin antibodies and of peptide C residual secretion on the metabolic control of diabetes type 1].

In 20 type I diabetic patients treated with conventional insulin preparations, we measured insulin antibodies and peptide C secretion. Peptide C levels 90 and 120 min after a standard breakfast correlated well with glucosylated Hb levels (r = -0.48 and -0.52, respectively). No correlation with free insulin levels was observed, in spite of a good correlation of the latter with blood glucose levels (r = -0.50 and -0.73, respectively). There was no relation between insulin antibody levels and peptide C or free insulin. Metabolic control was not affected by insulin antibodies. Insulin dose decreased in relation to the duration of the disease and reduction of body weight index and was not correlated to glycosylated Hb levels.

Adult↗
PubMed1989

[Clinical use of CA-125 in gynecology. Preliminary experience].

CA-125 levels were measured in 27 normal women, 11 with benign gynecologic pathology and 13 with ovarian cancer in different stages of evolution. The analysis of data was made retrospectively. Considering a level of 65 U/ml as normal, no false positives were found. Patients with benign gynecologic pathology behave as the normal ones with no significative differences in their levels. Levels higher that 65 U/ml were always found in women with ovarian cancer. There were 4 patients with negative levels and clinically or surgically verified disease. Positive levels correlated with histologic type and with surgical staging. In patients with serial levels, decrease in tumoral volume was correlated with decrease in levels. These data suggest that the behaviour of CA-125 in our local population is the same as reported in the literature. It is useful, when is positive, in follow-up, management and prognosis of patients with ovarian cancer. Its negativity is not guarantee of cure and positive levels make evident the presence of the disease. It is a poor diagnostic method because of its low sensitivity.

Antibodies, Monoclonal↗
PubMed1989

[Blood cell count in a reference chilean population].

Since the 1930's peripheral blood cell counts are among the most common clinical tests contributing to diagnosis of a wide variety of diseases. The original Schilling formula, based on findings in a European population at the beginning of this century are still used as reference in our country. We therefore report the values found in a population of both sexes without manifest disease and qualifying to be blood donors. Means, 5 and 95 percentiles for 212 males and 43 females obtained with the use of a Technicon H6000 are reported.

Adult↗
PubMed1989

[Serum lipids, HDL2 and HDL3 cholesterol and apolipoproteins A1 and B as predictors of coronary artery disease diagnosed by coronarography].

Serum levels of total, HDL2 and HDL3 cholesterol, triglycerides and apolipoproteins A1 and B were compared in 100 Chilean males with (n = 80) or without (n = 20) coronary artery disease (CAD). The presence and severity of CAD was determined by an angiographic score. Discriminating power, sensitivity, specificity and positive predictive value for CAD were calculated for all variables. As an isolated factor, total cholesterol had the greatest discriminating power (p less than 0.002): 21% of patients with CAD had cholesterol levels below 200 mg/dl while no patient with cholesterol over 275 mg/dl was free of disease. Even though all cases with HDL cholesterol below 25 mg/dl belonged in the CAD group, this factor had no overall discriminating power. Total cholesterol/HDL cholesterol ratio had the greatest discriminating power (p less than 0.001) while total/HDL2 cholesterol had the best positive predictive value.

Adult↗
PubMed1989

[Beta 2 microglobulin in some hematologic neoplasms].

Beta 2 microglobulin is a low molecular weight protein integrating the light chain HLA antigens. Its serum concentration is increased in different neoplasias and in renal failure. Using solid phase RIA we determined the concentration of beta 2 microglobulin in plasma and spinal fluid of 57 healthy individuals and patients with hematologic neoplasia. Serum levels were 1.34 +/- 0.34 mg/l and spinal fluid levels were 1.3 +/- 0.7 mg/l in healthy subjects. Serum levels in 29 patients with myeloma was 7.51 mg/l, significantly higher in those with renal failure (12.35 mg/l) compared to those without (4.54). In 30 patients with non-Hodgkin lymphoma the mean serum levels were 2.90 mg/l, significantly greater in those with active disease (3.18) than in those with remission (1.5). No difference was found according to the degree of malignancy. Patients with acute lymphatic leukemia had elevated values of beta 2 microglobulin while the disease was active (3.37 mg/l), decreasing to normal levels after remission (1.79 mg/l). Spinal fluid levels of beta 2 microglobulin were elevated only in patients with central nervous system involvement. Our results indicate that serum levels of beta 2 microglobulin are helpful in patients with hematologic neoplasia in assessing the activity of the disease and tumor mass, especially in multiple myeloma.

Adolescent↗
PubMed1989

[Deficiency of folates in pregnancy: effect of supplementary folic acid].

Higher folate needs are present during pregnancy, which may lead to tissular deficiency in the mother and to depleted newborn folate reserves. The aim of this work was to assess the prevalence of folate deficiency and to establish the rates of serum and red cell folate in two groups of mothers and newborn infants, one receiving only iron and the other iron and folate during pregnancy. The rates of serum and red cell folate found at the end of pregnancy were significantly higher in the group which received folate; however, the percentage of cases with tissular folate deficiency was low in both groups, with no significant difference (3.8% and 1.3%, respectively). These findings, along with the lack of effect of supplemental folate on erythropoiesis, pose some questions on the usefulness of supplemental folate during pregnancy in our country.

Adult↗
PubMed1986

Comparative study of size, total protein, fibrinogen and 5-HT content of human and canine platelet density subpopulations.

The size, total protein, fibrinogen and 5-HT content were evaluated in density subpopulations of human and canine platelets fractionated in linear arabinogalactan gradients. The methodology was assessed to ascertain that platelet separation was by density and to discard artifactual changes and platelet release during the procedure. EDTA or PGE1 increased the size of human PRP-platelets, but not of dog platelets. In humans, high density (HD) platelets were 1.26 times larger and contained 1.88 times more fibrinogen, 2.23 times more 5-HT and 1.37 times more protein than low density (LD) platelets; in dogs, these density cohorts did not differ in protein content, but LD platelets were 1.29 times larger and had 1.33 times more fibrinogen and 5-HT than HD platelets. These findings suggest that cell density is mostly dependent on the protein content per unit volume of platelets (and not on dense bodies). The differences in fibrinogen and 5-HT content between HD and LD cohorts in humans and dogs may be related to platelet age. The difference in volume between HD and LD platelets in dogs is of uncertain interpretation.

Aging↗
PubMed1986

Response of the maternal, fetal, and neonatal pituitary-thyroid axis to thyrotropin-releasing hormone.

Thyrotropin releasing hormone (TRH) readily crosses the placenta and stimulates the fetal pituitary. We studied the response of the maternal and fetal pituitary-thyroid axes to TRH and the influence of prenatal exposure to TRH on the physiological postnatal increase in thyrotropin (TSH) and triiodothyronine (T3) in the neonate. Twenty-six pregnant women received TRH (400 or 600 micrograms) intravenous or saline (controls) either 2 or 12 h before elective cesarean section at term. Administration of 400 micrograms of TRH resulted in significant elevations of maternal TSH (15.7 +/- 2.9 versus 3.2 +/- 0.4 microU/ml, p less than 0.01) and prolactin (416 +/- 94 versus 223 +/- 41 ng/ml, p less than 0.05) 2 h later. Maternal T3 remained unchanged. A higher dose of TRH (600 micrograms) produced comparable results. Maternal administration of TRH (400 micrograms) 2 h before delivery resulted in significant increases in fetal TSH and T3 over controls (21.1 +/- 3.7 versus 4.8 +/- 1.0 microU/ml, and 132 +/- 12 versus 64 +/- 9 ng/dl, p less than 0.01, respectively). Cord blood hormone levels 12 hours after TRH administration were similar to controls. Higher doses of TRH did not produce further increases in fetal TSH or T3. Control and treated neonates demonstrated similar physiological postnatal increases in TSH and T3, suggesting that prior exposure to TRH did not blunt this response. These data suggest that maternal administration of TRH is an effective way of increasing fetal T3 levels, and that this treatment does not inhibit the postnatal surge in TSH and T3.

Female↗