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E Jimenez

Publications and source records attributed to E Jimenez.

At least 55 records · Page 3Linked to original sources
PubMed1998

Cross-reactivity between Candida albicans and human ovarian carcinoma as revealed by monoclonal antibodies PA10F and C6.

Summary Antibodies against Candida albicans antigenic determinants have been reported to cross-react with human tumour cells. We have found that two monoclonal antibodies, C6 and PA1OF, developed at our laboratory against C. albicans antigenic determinants, cross-react with human ovarian cancer on Western blots and immunohistochemistry. We have subsequently used one of them, PA10OF, to test by means of immunohistochemistry a series of 37 human ovarian carcinomas. Out of 37 tumours, 25 (67.6%) expressed the antigen recognized by PA1OF. The reactivity, however, was concentrated on the subgroup of particularly aggressive, invasive carcinomas in advanced stages of the disease (19 out of 24 positive), whereas the antigen was expressed significantly less (P=0.0007) in the subgroup of much less aggressive stage I tumours of low malignant potential, also called borderline carcinomas (2 out of 13 positive). This cross-reactivity between C. albicans and ovarian carcinoma seems to be attributable to a common antigenic determinant related to tumour aggressiveness.

Animals↗
PubMed1998

Pharmacokinetics of nevirapine in human immunodeficiency virus type 1-infected pregnant women and their neonates. Pediatric AIDS Clinical Trials Group Protocol 250 Team.

The safety, toxicity, and pharmacokinetics of intrapartum and early newborn nevirapine were evaluated in 17 human immunodeficiency virus type 1-infected women in labor and their newborns. No adverse effects of nevirapine were noted in any study mothers or infants. Following maternal dosing with 200 mg during labor, concentrations exceeding 100 ng/mL (10 times the in vitro IC50) were achieved in the newborns. Nevirapine elimination was prolonged in both mothers and infants, with median half-lives ranging from 36.8 to 65.7 h. Administration of 200 mg orally to the mothers in labor and of a single 2-mg/kg oral dose to the infants at 48-72 h after birth maintained serum concentrations in the infants > 100 ng/mL through 7 days of life.

Adult↗
PubMed1998

Ovulation induction with pulsatile GnRH in a patient with anovulation of hypothalamic origin and central diabetes insipidus.

Patients with diabetes insipidus (DI) are at high risk for dehydration, hypernatremia and hemodynamic instability. Ovarian hyperstimulation syndrome (OHSS) likewise has negative effects on electrolyte balance. If ovulation induction is required in a patient with DI, there is thus a strong argument for avoiding techniques that increase the risk of OHSS. This paper reports the results of ovulation induction in a patient with anovulation of hypothalamic origin and central (vasopressin deficit) DI. Ovulation was induced with pulsatile gonadotropin-releasing hormone (GnRH), which induces single-ovule cycles and which does not increase the risk of OHSS. The patient successfully achieved pregnancy after seven ovulatory cycles.

Adult↗
PubMed1997

Endothelin receptor-mediated Ca2+ mobilization and contraction in bovine oviductal arteries: comparison with noradrenaline and potassium.

1. The effects of endothelin-1 (ET-1) were studied in bovine oviductal arteries and compared to those of noradrenaline (NA) and high K+ (K+). The influence of endothelium, the receptor subtypes involved, and the mechanisms of Ca2+ mobilization were assessed. 2. ET-1 (0.1-300 nM) induced concentration-dependent contractions with a potency of 10(3) and 10(2) times higher than NA (0.1 microM-0.1 mM) and K+ (9.5-119 mM), respectively. Removal of endothelium or NG-nitro-L-arginine (L-NOARG, 0.1 mM) pretreatment did not affect responses to either ET-1 or K+, whereas the NA response was significantly increased. Indomethacin (1 microM) had no effect on either of these agonists. 3. The rank order of potency for the ET isopeptides was: ET-1 = ET-2 > ET-3. The ETA receptor-selective agonist, sarafotoxin 6c (S6c), had no effect. The ETA receptor-selective antagonist, BQ-123, showed a competitive antagonism on the ET-1 response (pA2 value of 6.58 +/- 0.01), whereas contractions to ET-3 were completely abolished by BQ-123 at 0.1 microM. 4. Concentration-response curves to both ET-1 and NA were shifted to the right and their maximum response reduced to approximately 56% and 65% of controls, respectively, under 30 min of incubation in Ca(2+)-free solution, whereas responses to K+ were almost abolished by this treatment. Contractions to both NA (30 microM) and ET-1 (30 nM) were maximally inhibited after 10 min of extracellular Ca2+ deprivation. 5. Contractions to ET-1 were more potently inhibited by nickel (Ni2+, 0.3 mM), whereas nifedipine (1 microM) and cadmium (Cd2+, 0.1 mM) induced only a slight effect. In contrast, opposite effects were found for both NA and K+. 6. Treatment with ryanodine (100 microM) and caffeine (10 mM) in Ca(2+)-free solution reduced the tension measured 5 min after NA (30 microM) and ET-1 (30 nM) addition, but the sustained response (tension at 25 min) remained unaffected. 7. Calphostin C (1 microM), a specific protein kinase C (PKC) inhibitor, reduced the maximum contractile response to ET-1 by about 50% without significantly affecting its pD2 value. 8. These results suggest that ET-1 acts in bovine oviductal arteries by directly activating a homogenous population of ETA receptors in smooth muscle, without endothelial modulation. Several Ca2+ activation mechanisms seem to be involved in the contractile action of the peptide, including: (1) extracellular Ca2+ entrance through Ni(2+)-sensitive and L-type Ca2+ channels; (2) intracellular Ca2+ release from a ryanodine-sensitive Ca2+ store; and (3) sensitization of the contractile machinery to Ca2+ via PKC.

Animals↗
PubMed1997

Insulin promotes the hydrolysis of a glycosyl phosphatidylinositol in cultured rat astroglial cells.

Glycosyl phosphatidylinositols have been implicated in insulin signaling through their action as precursors of second messenger molecules in peripheral tissues. In the present study, cultured rat astrocytes were used to investigate whether glycosyl phosphatidylinositol might be involved in the mechanism of insulin signal transduction in neural cells. A glycosyl phosphatidylinositol sensitive to hydrolysis by both phosphatidylinositol-specific phospholipase C and glycosyl phosphatidylinositol-specific phospholipase D and to nitrous acid deamination was purified. When astrocytes were exposed to 10 nM insulin, a rapid and significant reduction in the content of glycosyl phosphatidylinositol was observed within 1-2 min. In addition, an inverse concentration-dependent relationship between glycosyl phosphatidylinositol and diacylglycerol levels was found, suggesting a phospholipase C-mediated hydrolysis of glycosyl phosphatidylinositol in response to insulin. The effects of insulin were mediated through its own receptors and not through insulin-like growth factor (IGF)-I and/or IGF-II receptors, as demonstrated by affinity cross-linking studies. Also, the effects of 5 nM IGF-1 or 5 nM IGF-II on glycosyl phosphatidylinositol and diacylglycerol levels were different from those caused by insulin and were not essentially modified by pretreatment of the cells with either platelet-derived growth factor (PDGF) or epidermal growth factor (EGF). When cells were sequentially incubated with PDGF and EGF, a reduction in both glycosyl phosphatidylinositol and diacylglycerol contents was observed; the diacylglycerol but not the glycosyl phosphatidyl content was reversed after incubation with IGF-I, and especially with IGF-II, for 10 min. Despite the remarkable homology among insulin, IGF-I, and IGF-II, our results indicate that in astrocytes these compounds probably use different signal transduction pathways.

Animals↗
PubMed1997

Evaluation of pharmacokinetics, safety, tolerance, and activity of combination of zalcitabine and zidovudine in stable, zidovudine-treated pediatric patients with human immunodeficiency virus infection. AIDS Clinical Trials Group Protocol 190 Team.

A double-blind phase II trial compared zalcitabine (0.03 mg/kg/day) in combination with zidovudine (720 mg/m2/day) and zidovudine monotherapy in 250 clinically stable, previously zidovudine-treated, human immunodeficiency virus-infected children. The combination was well-tolerated except for an increased incidence of neutropenia (14%) compared with that in children receiving monotherapy (5%). No differences were noted for time to first AIDS-defining illness or death, neuropsychologic status, or weight Z scores. In patients in the combination arm, the CD4 cell count decline was slower (13% per year) than in patients receiving monotherapy (25% per year) (P = .03), and quantitative peripheral blood mononuclear cell virus load remained lower at all time points (P = .08). Deaths were fewer in patients receiving combination therapy (4) compared with those in patients receiving monotherapy (10) (P = .083). Thus, administration of zidovudine with zalcitabine to children with prior zidovudine treatment did not result in a significant increase in toxicity compared with that resulting from zidovudine monotherapy and demonstrated improvement in immunologic and virologic surrogate markers.

AIDS-Related Opportunistic Infections↗
PubMed1997

Safety and pharmacokinetics of hyperimmune anti-human immunodeficiency virus (HIV) immunoglobulin administered to HIV-infected pregnant women and their newborns. Pediatric AIDS Clinical Trials Group Protocol 185 Pharmacokinetic Study Group.

The pharmacokinetics and safety of hyperimmune anti-human immunodeficiency virus (HIV) intravenous immunoglobulin (HIVIG) were evaluated in the first 28 maternal-infant pairs enrolled in a randomized, intravenous immunoglobulin (IVIG)-controlled trial of HIVIG maternal-infant HIV transmission prophylaxis. Using 200 mg/kg, mean half-life and volume of distribution (Vd) in women were 15 days and 72 mL/kg, respectively, after one and 32 days and 154 mL/kg after three monthly infusions, with stable 4 mL/kg/day clearance. Transplacental passage occurred. Newborn single-dose half-life, Vd, and clearance were 30 days, 143 mL/kg, and 4 mL/kg/day, respectively. HIVIG rapidly cleared maternal serum immune complex-dissociated p24 antigen, and plasma HIV-1 RNA levels were stable. Mild to moderate adverse clinical effects occurred in 2 of 103 maternal and 2 of 25 infant infusions. No adverse hematologic, blood chemistry, or immunologic effects were seen. HIVIG is well-tolerated in HIV-infected pregnant women and their newborns, clears antigenemia, crosses the placenta, and exhibits pharmacokinetics similar to those of other immunoglobulin preparations.

Adolescent↗
PubMed1996

Maternal viral load, zidovudine treatment, and the risk of transmission of human immunodeficiency virus type 1 from mother to infant. Pediatric AIDS Clinical Trials Group Protocol 076 Study Group.

BACKGROUND AND METHODS: A placebo-controlled trial has shown that treatment with zidovudine reduces the rate at which human immunodeficiency virus type 1 (HIV-1) is transmitted from mother to infant. We present data from that trial showing the number of infected infants at 18 months of age and the relation between the maternal viral load, the risk of HIV-1 transmission, and the efficacy of zidovudine treatment. Viral cultures were obtained, and HIV-1 RNA was measured by two assays in samples of maternal blood obtained at study entry and at delivery. RESULTS: In 402 mother-infant pairs, the rate of transmission of HIV-1 was 7.6 percent (95 percent confidence interval, 4.3 to 12.3 percent) with zidovudine treatment and 22.6 percent (95 percent confidence interval, 17.0 to 29.0 percent) with placebo (P<0.001). In the placebo group, a large viral burden at entry or delivery or a positive culture was associated with an increased risk of transmission (the transmission rate was greater than 40 percent in the highest quartile of the RNA level). In both groups, transmission occurred at a wide range of maternal plasma HIV-1 RNA levels. Zidovudine reduced plasma RNA levels somewhat (median reduction, 0.24 log). Zidovudine was effective regardless of the HIV-1 RNA level or the CD4+ count at entry. In the zidovudine group, however, after we adjusted for the base-line HIV-1 RNA level and CD4+ count, the reduction in viral RNA from base line to delivery was not significantly associated with the risk of transmission of HIV-1. CONCLUSIONS: A high maternal plasma concentration of virus is a risk factor for the transmission of HIV-1 from an untreated mother to her infant. The reduction in such transmission after zidovudine treatment is only partly explained by the reduction in plasma levels of viral RNA. To prevent HIV-1 transmission, initiating maternal treatment with zidovudine is recommended regardless of the plasma level of HIV-1 RNA or the CD4+ count.

Anti-HIV Agents↗
PubMed1996

Iron-deficiency anemia and infant development: effects of extended oral iron therapy.

OBJECTIVE: To determine whether extended oral iron therapy corrects lower developmental test scores in infants with iron-deficiency anemia. STUDY DESIGN: Double-blind, controlled trial in Costa Rica involving 32 12- to 23-month-old infants with iron-deficiency anemia and 54 nonanemic control subjects. Anemic infants were treated with orally administered iron for 6 months; half the nonanemic children were treated with iron and half with placebo. Developmental test scores and hematologic status were evaluated before treatment, after 3 months, and after 6 months. RESULTS: Iron-deficient anemic infants received lower mental test scores than nonanemic infants at all three time points (p < 0.05 pretreatment and at 3 months, p = 0.07 at 6 months). There were no significant differences in motor test scores. More of the anemic infants were rated as unusually tearful and unhappy. Anemic infants came from families with lower maternal education and less support for child development and were less likely to be breast fed, were weaned earlier, and consumed more cow milk. CONCLUSIONS: Lower mental test scores persisted in infants with iron-deficiency anemia despite extended oral iron therapy and an excellent hematologic response. Iron-deficiency anemia may serve as a marker for a variety of nutritional and family disadvantages that may adversely affect infant development.

Administration, Oral↗
PubMed1996

Randomized study of the tolerance and efficacy of high- versus low-dose zidovudine in human immunodeficiency virus-infected children with mild to moderate symptoms (AIDS Clinical Trials Group 128). Pediatric AIDS Clinical Trials Group.

The current dosage of zidovudine for children is 180 mg/m2 every 6 h. To investigate whether a lower dosage was equally effective, human immunodeficiency virus (HIV)-infected children (3 months to 12 years) with mild to moderate symptoms were randomly assigned to receive either high-dose (180 mg/m2/dose) or low-dose (90 mg/m2/dose) zidovudine (double-blind). Treatments were compared with respect to neuropsychologic function, survival, clinical and laboratory evidence of disease progression, and safety and tolerance. Four hundred twenty-six HIV-infected children were enrolled; median time for receipt of study drug was 35 months. Zidovudine in either dose was well tolerated, with no difference in efficacy or tolerance by treatment group using any clinical or laboratory parameter. In children with mild to moderate disease, a reduction of zidovudine to 90 mg/m2/dose will result in substantial cost savings and should be the recommended dose.

AIDS Dementia Complex↗
PubMed1995

Serum prolactin levels and behavior in infants.

This study examined the relationship between serum prolactin levels and behavior in infants and toddlers who experienced two potentially stressful experiences (developmental testing and venipuncture). Serum prolactin levels showed considerable consistency over a 3-month period (r = 0.64 between study entry and three months, p < 0.001, n = 50). There was also stability in having either a normal or a high value (> or = 25 ng/ml). Among children who had a normal value on initial testing, 97% also has a normal value after 3 months; 55% of those with initial high values continued to have high values (chi 2 = 19.26, p < 0.001). Children with high serum prolactin levels were more likely to be rated as unusually hesitant and unhappy during developmental testing. Overall, 53% of the children with serum prolactin levels > or = 25 ng/ml were considered abnormal in affect, compared to 20% of those with lower serum prolactin values (total n = 138, chi 2 = 13.56, p < 0.001). These results suggest that, even in early life, serum prolactin levels may reflect characteristic individual behavioral and neuroendocrine responses to stress.

Female↗
PubMed1995

Biphasic response of complement to heparin: fluid-phase generation of neoantigens in human serum and in a reconstituted alternative pathway amplification cycle.

We describe a study of the effects of heparin on complement activation through the use of assays for fragment C4d, fragment Bb, and the S-C5b-9 complex (S-MAC). In sera from healthy volunteers, virtually no change was observed in C4d either as a function of time or of heparin concentration, whereas changes in Bb and S-MAC were biphasic. This observation was explored in greater detail in the heparin concentration range 0.001-5.0 u/ml (5 x 10(-3) to 25 micrograms/ml). For both Bb and S-MAC, a significant (P < 0.05) increase in production was noted in the heparin concentration range, 0.01-0.5 u/ml (5 x 10(-2) to 2.5 micrograms/ml). At higher heparin concentrations, Bb and S-MAC production decreased markedly (P < 0.05). We reconstituted the alternative pathway amplification cycle (C3, factor B, and factor D) and studied Bb generation. With reactants at concentrations one tenth those of normal serum, we observed a maximum generation of 13.2 micrograms/ml Bb. Control and heparin at 5 x 10(-4) micrograms/ml generated Bb concentrations of 6.8 and 6.1 micrograms/ml, respectively, for a 2-min incubation; at 5 x 10(-3) micrograms/ml heparin, Bb was increased to 9.8 micrograms/ml. Using isoelectric focusing to study anionic pI shifts in heparin-bound factors B and D, it was found that factor B bound heparin only at the highest heparin concentration studied, i.e., 50 micrograms/ml; factor D, however, bound heparin at a much lower concentration (0.05 micrograms/ml). We conclude that, at low concentrations, heparin activates complement due to potentiation of the alternative pathway amplification cycle in the fluid phase.

Adult↗
PubMed1995

Macrophage-lymphocyte cell clusters in the hypothalamic ventricle of some elasmobranch fish: ultrastructural analysis and possible functional significance.

BACKGROUND: Previous studies have demonstrated the existence of lympho-haemopoietic tissue in the meninges and choroid plexuses of various primitive vertebrates, including the stingray Dasyatis akajei and in early human embryos. In the present study, we extend these results analyzing macrophage-lymphocyte cell clusters found in the floor of the hypothalamic ventricle of several specimens of elasmobranchs. METHODS: After aseptical isolation of the brain from several specimens of smooth dogfish Triakis scyllia, cloudy dogfish Scyliorhinus torazame, gummy shark Mustelus manazo, and stingray Dasyatis akajei their hypothalamic regions were processed routinely by light, scanning, and transmission electron microscopy. RESULTS: The study of serial histological sections demonstrated that the macrophage-lymphocyte cell clusters proceeded from the meningeal lymphohaemopoietic tissue, reaching the ventricular lumen along large blood vessels. In this tissue, macrophages, different sized lymphocytes, lymphoblasts, granulocytes, monocytes, and developing and mature plasma cells were closely packed among a meshwork of fibroblastic reticular cell processes. It never invaded the brain parenchyma. A cell layer of glial elements and a continuous basement membrane interposed between the lymphoid tissue and the neural elements although some macrophages had migrated across the ependymal cell layer. In the ventricular lumen very irregular macrophages with long cell processes and containing abundant engulfed material of unknown origin formed big cell clusters with neighboring lymphocytes, lymphoblasts, and plasma cells, similar to those described during the immune response. Moreover, electron lucent cells which resembled the antigen-presenting cells of higher vertebrates established intimate surface cell contacts with the surrounding lymphocytes. In the third ventricle of several specimens of gummy shark, Mustelus manazo, morphologically similar cell clusters appeared but these were not connected to the meningeal lympho-haemopoietic tissue. No intraventricular cell aggregates were found in the stingray brain. CONCLUSIONS: Although we cannot rule out that these macrophage-lymphocyte cell clusters represent a permanent structure in the elasmobranch brain they rather seem to be only established after specific stimulation for preventing the entrance of noxious, foreign materials into the elasmobranch brain parenchyma.

Animals↗
PubMed1995

Endothelium-dependent relaxation to acetylcholine in bovine oviductal arteries: mediation by nitric oxide and changes in apamin-sensitive K+ conductance.

1. Mechanisms underlying the relaxant response to acetylcholine (ACh) were examined in bovine oviductal arteries (o.d. 300-500 microns and i.d. 150-300 microns) in vitro. Vascular rings were treated with indomethacin (10 microM) to prevent the effects of prostaglandins. 2. ACh elicited a concentration-related relaxation in ring segments precontracted with noradrenaline (NA), which was abolished by endothelium denudation. 3. The ACh-induced relaxation was attenuated but not abolished by NG-nitro-L-arginine (L-NOARG, 1 microM-1 mM), an inhibitor of nitric oxide (NO) formation. The inhibition caused by L-NOARG (10 microM) was reversed by addition of excess of L-arginine but not D-arginine (1 mM). 4. In high K+ (40-60 mM)-contracted rings, ACh was a much less effective vasodilator and its relaxant response was completely abolished by L-NOARG (100 microM). 5. In NA (10 microM)-contracted rings, ACh induced sustained and concentration-dependent increases in cyclic GMP, which were reduced below basal values by L-NOARG (100 microM), while potent relaxation persisted. Similar increases in cyclic GMP were evoked by ACh in high K+ (50 mM)-treated arteries and under these conditions, both cyclic GMP accumulation and relaxation were L-NOARG-sensitive. 6. S-nitroso-L-cysteine (NC), a proposed endogenous precursor of endothelial NO, also induced cyclic GMP accumulation in NA-contracted oviductal arteries. 7. Methylene blue (MB, 10 microM), a proposed inhibitor of soluble guanylate cyclase, inhibited both endothelium-dependent relaxation to ACh and endothelium-independent response to exogenous NO, whereas relaxation to NC remained unaffected. 8. The L-NOARG-resistant response to ACh was not affected by either ouabain (0.5 mM), glibenclamide (3 microM), tetraethylammonium (TEA, 1 mM) or charybdotoxin (50 nM), but was selectively blocked by apamin (0.1-1 microM). However, apamin did not inhibit either relaxation to ACh in high K(+)-contracted rings or endothelium-independent relaxation to either NO or NC. 9. Apamin and MB inhibited ACh-induced relaxation in an additive fashion, suggesting the involvement of two separate modulating mechanisms. 10. These results suggest that ACh relaxes bovine oviductal arteries by the release of two distinct endothelial factors: a NO-like substance derived from L-arginine, which induces cyclic GMP accumulation in smooth muscle, and another non-prostanoid factor acting by hyperpolarization mechanisms through alterations in apamin-sensitive K+ conductance.

Acetylcholine↗
PubMed1994

Vertical human immunodeficiency virus transmission: a study of placental pathology in relation to maternal risk factors.

We examined 48 placentas of human immunodeficiency virus (HIV)-exposed pregnancies morphologically for HIV-specific changes and immunohistologically for the presence of HIV antigen and RNA. Findings were correlated to infectious states of the children and maternal risk factors. Few HIV antigen-positive Hofbauer cells and HIV RNA positive syncytiotrophoblast and Hofbauer cells were detected. HIV-positive cells in the placenta did not correlate with intrauterine infection and maternal immunologic parameters. Light microscopically, we found two changes: immaturity of the terminal villi and allantois vasculopathy. These changes, however, are not HIV specific. Our results show that vertical HIV transmission cannot be diagnosed by morphological examination of the placenta.

Acquired Immunodeficiency Syndrome↗