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Biomedical subjects

R Bustos

Publications and source records attributed to R Bustos.

10 recordsLinked to original sources
PubMed1992

Stimulation of glycolysis as an activation signal in rat peritoneal macrophages. Effect of glucocorticoids on this process.

1. Peritoneal macrophages were prepared from control, Escherichia coli-treated and triamcinolone acetonide-treated rats. Control and E. coli-treated rats produced resident and activated macrophages respectively. Glycolysis in these cells was studied by the fructose 2,6-bisphosphate (Fru-2,6-P2) content, lactate release and 6-phosphofructo-1-kinase (PFK-1) and 6-phosphofructo-2-kinase (PFK-2) activities. 2. In activated macrophages, lactate release and Fru-2,6-P2 content were increased several-fold compared with those in resident cells. Moreover, the response of these parameters to phorbol 12-myristate 13-acetate in activated macrophages was greater than for resident cells. 3. PFK-2 activity was moderately increased (about 3-fold), but PFK-1 activity was increased 5-fold in activated macrophages compared with resident cells. Partially purified preparations of PFK-1 were sensitive to Fru-2,6-P2, with K0.5 about 0.25 microM in both control and activated cells. However, the Vmax. of PFK-1 from activated cells was increased. In addition, AMP stimulated PFK-1, but the kinetic pattern was different from that described for Fru-2,6-P2. Moreover there was no difference in the stimulation by AMP of PFK-1 from resident and activated cells. 4. Fru-2,6-P2 content and lactate release in macrophages from triamcinolone acetonide-treated rats were decreased in both resident and activated cells. Also, the glucocorticoid inhibited PFK-1 and PFK-2 activities in both resident and activated macrophages. PFK-1 from triamcinolone acetonide-treated rats was not stimulated by Fru-2,6-P2, whereas the effect of AMP was unchanged. The effects of glucocorticoid seem to be specific for phagocytic cells, since the glucocorticoid treatment increased PFK-1 and PFK-2 activities in liver.

Animals↗
PubMed1989

Control of fructose 2,6-bisphosphate levels in rat macrophages by glucose and phorbol ester.

The presence of fructose 2,6-bisphosphate (Fru 2,6-P2) in elicited peritoneal macrophages of rat was examined. These cells possess an active phosphofructokinase-2 which is diminished by citrate and only slightly inhibited by glycerol 3-phosphate. Phosphofructokinase-1 submaximal activity was increased 26-fold by the addition of 1 microM Fru 2,6-P2. Incubation of cells without glucose decreased the amount of Fru 2,6-P2 to zero, but further addition of 5 mM glucose increased the levels of the sugar ester 20-fold. In addition, the presence of phorbol ester potentiated the synthesis of Fru 2,6-P2. By contrast phenylisopropyladenosine or prostaglandin F2 alpha inhibited the production of Fru 2,6-P2.

Animals↗
PubMed1979

Significance of phosphatidylglycerol in amniotic fluid in complicated pregnancies.

In normal pregnancy lecithin/sphingomyelin ratios correlate with gestational age. In complicated pregnancies biochemical maturation of fetal lung may be accelerated or delayed, depending upon maternal, fetal, or placental conditions. Surfactant contains other phospholipids besides lecithin, including phosphatidylglycerol (PG), the second major component of mature surfactant. Ninety phospholipid patterns in amniotic fluid were studied by two-dimensional thin-layer chromatography. In uncomplicated pregnancies PG was absent until 37 weeks' gestation, then increased there after. In complicated pregnancies (pre-eclampsia, diabetes Classes D, F, and R, premature rupture of membranes) PG was identified before 35 (as early as 29 weeks' gestation. These results verify accelerated lung maturation in certain complicated pregnancies. No newborn infant developed respiratory distress syndrome in the presence of PG.

Amniocentesis↗
PubMed1975

Heart rate in fetuses and neonates in normal conditions and with mild depression.

The continuous recording of fetal and neonatal heart rate gives reliable information on the condition of the fetus and neonate. In the present study the results obtained in vigorous and mildly depressed newborns, by the continuous recording of fetal heart rate during labor and of neonatal heart rate during 90 minutes after birth, are presented. Twenty three pregnant women were studied during labor, as well as their newborns. They fulfilled the following conditions: --Mothers without known complications and good prenatal care. --Term pregnancies with single fetuses in vertex presentation with birthweight normal for age. --All labors started, progressed and delivered spontanously withoug signs of fetal distress. No drugs were given to the mother during labor or to the neonate. The umbilical cord was clamped immediately after birth. Seventeen neonates were vigorous at 1 and 5 minutes (Apgar score 7 or higher). Six neonates were slightly depressed at the first minute but all of them recovered at 5 minutes. Both groups are studied separately. Figure 1 shows the average values of BFHR and NHR corresponding to 17 vigorous newborns (Apgar scores 7-10 at the first and fifth minutes of life). No major variations were found in the average values of BFHR in the time period studied. No statistically significant differences were found in the BFHR of the same fetus at 60, 30 and 8 minutes before delivery (Fig. 2). A decrease in BFHR occurred during the 6 minutes preceding birth (fig. 1). After birth the average values of NHR were higher than the fetal ones (Fig. 1). This post-natal increase in heart rate (32 beats/min) is statistically significant when BFHR values 30 minutes before delivery are compared with NHR values recorded 10 minutes after birth (Fig. 3). After this initial increase, NHR starts a gradual fall, lasting about 50 minutes and then becomes stable at a level similar to that of fetal heart rate (Fig. 1). Figure 1 shows that puncture of the heel causes an increase in NHR. The difference between NHR before and after the puncture is significant (Fig. 6). The heart rate of 6 newborns which were slightly depressed at the first minute of life (Apgar score 4-6) but vigorous at the fifth minute, are not significantly different from those of the vigorous group of 17 neonates (Fig.7). The cases chosen for this study have been carefully selected with the aim of establishing the "normal" pattern of fetal and neonatal heart rate. We concluded that in normal term labors BFHR remains stable from 90 until 10 minutes before delivery; there is a tendency to fall during the last 6 minutes preceeding birth. Immediately after birth, neonatal heart rate rises significantly, then falls gradually and becomes stabilized 50 minutes after delivery, at levels similar to those of BFHR.

Adolescent↗