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Biomedical subjects

E Avila

Publications and source records attributed to E Avila.

At least 19 recordsLinked to original sources
PubMed2001

Calcitonin gene- and parathyroid hormone-related peptides in preeclampsia: effects of magnesium sulfate.

OBJECTIVE: To determine whether circulating levels of calcitonin gene-related peptide (CGRP) and parathyroid hormone-related peptide (PTHrP) are altered in preeclampsia, and to assess the effects of magnesium sulfate therapy on circulating levels of these two peptides. METHODS: The study population included 25 women with preeclampsia and 25 normotensive controls of similar gestational age. The effects of magnesium sulfate therapy were evaluated in 17 of the 25 preeclamptic women. Circulating levels of immunoreactive CGRP and PTHrP, including calcium, magnesium, and phosphate in the maternal and umbilical cord serum were measured. RESULTS: The frequency of preeclampsia subjects with nondetectable PTHrP (under 3 pg/mL) was significantly higher (92% versus 48%, P <.001), whereas maternal serum CGRP levels were significantly lower (50 +/- 19 versus 90 +/- 23 pg/mL, P <.001). Similarly, the frequency of newborns with nondetectable PTHrP levels in umbilical serum was significantly higher (68% versus 36%, P <.05), whereas the levels of CGRP were significantly lower (67 +/- 17 versus 79 +/- 16 pg/mL, P <.05). Magnesium sulfate treatment resulted in a significant increase in maternal circulating CGRP levels (64 +/- 17 versus 47 +/- 18 pg/mL, P <.05) with no changes in PTHrP. CONCLUSION: Maternal circulating PTHrP and CGRP concentrations were significantly lower in women with preeclampsia, which may contribute to the development and maintenance of hypertension during pregnancy. Furthermore, magnesium sulfate therapy increased the levels of CGRP in the maternal circulation.

Adult↗
PubMed2000

Endoscopic plastic surgery.

This article discusses three of the most popular endoscopic procedures in plastic surgery. Brow lift, transaxillary breast augmentation, and abdominoplasty are all cosmetic procedures with a high demand on inconspicuous scars; however, many investigators are working on reconstructive endoscopically assisted procedures. The treatment of many facial fractures involving the upper third of the facial skeleton usually requires long bicoronal incisions similar to the incisions used in the traditional brow lift. Attempts are under way to use endoscopically assisted minimal-access techniques to reduce and fixate these fractures. Many flaps used in plastic surgery require long scars for harvest, as in the case of the latissimus dorsi muscle flap. A relatively long incision on the back is needed to gain access to the muscle so that it can be elevated from structures superficial and deep to it. Although it is unpopular, investigators have reported harvesting latissimus dorsi muscle flaps through fairly small incisions with the assistance of balloon dissectors and endoscopes. In the field of hand surgery, carpal tunnel release surgery has had more than one method proposed to transect the carpal ligament using endoscopes and special instrumentation. Although some reported series claim excellent results, many hand surgeons are reluctant to use endoscopes because of associated complications and a high recurrence rate of carpal tunnel syndrome. Plastic surgery has special demands that emphasize aesthetics in cosmetic and reconstructive procedures. Although the lack of natural optical cavities has slowed the incorporation of endoscopic surgery in the specialty, surgically created cavities are used to allow for minimal access incisions. The future of plastic surgery will include an ever-increasing number of endoscopically assisted procedures. Cosmetic and reconstructive procedures will benefit from this new technology.

Abdomen↗
PubMed2000

Characterization of methylaminoisobutyric acid transport by system A in rat mammary gland.

During lactation, the mammary gland has a large demand for amino acids for the synthesis of milk proteins and fatty acids. Arteriovenous differences in amino acids across the mammary gland show an elevated uptake of small neutral amino acids that are mainly transported via system A. The purpose of this study was to characterize the transport of methylaminoisobutyric acid (MeAIB), an amino acid analog used to model transport by system A in lactating rat mammary gland explants. MeAIB accumulation in mammary gland cells increased steadily, and after 3 hours of incubation, the intracellular concentration of the analog was 8-fold higher than the concentration in the medium. MeAIB transport into mammary gland explants showed a Km of 3.3 +/- 0.4 mmol/L and a maximal velocity (Vmax) of 555 +/- 23 pmol/microL intracellular fluid (ICF) x min, indicating a system with high capacity but low affinity for its substrate. MeAIB transport into mammary tissue depended highly on Na+, and the uptake was inhibited by addition of natural and analog small neutral amino acids. Cationic, anionic, and large neutral amino acids did not reduce MeAIB transport into mammary gland explants. Preincubation of mammary gland explants in an amino acid-free medium stimulated MeAIB transport, suggesting an adaptive regulation. The addition of an equimolar mixture of alanine, glycine, and serine to the preincubation medium inhibited stimulation of MeAIB transport. Furthermore, stimulation of MeAIB uptake by amino acid starvation was also prevented by the addition of actinomycin D, cycloheximide, tunicamycin, and colchicine. Dibutyryl cyclic adenosine monophosphate (cAMP) increased MeAIB uptake, whereas phorbol 12-myristate 13-acetate (PMA) did not stimulate MeAIB transport. During the first postweaning days, kinetic analyses showed a decrease of 27% in the Vmax. Injection of rat lactating mammary gland mRNA into Xenopus laevis oocytes induced expression of the MeAIB transport system; however, the induction was only 83% above background MeAIB uptake. The results of this study provide a partial explanation for the formation of the metabolic pool of small neutral amino acids in the lactating mammary gland.

Amino Acid Transport Systems↗
PubMed2000

Immunocytochemical, ultrastructural and neurochemical evidences on synaptogenesis and dopamine release of rat chromaffin cells co-cultured with striatal neurons.

The results reported herein address the question of synaptogenesis between adrenal chromaffin cells and striatal neurons. The release of dopamine from chromaffin cells in the presence of striatal neurons was also examined. Co-culture of newborn rat chromaffin cells and striatal neurons at 1:1 ratio was made. Cultures were examined morphologically using immunocytochemistry and ultrastructural techniques (transmission electron microscopy), while quantitation of dopamine in the culture media by HPLC-ECD was also determined. Neurite outgrowth from chromaffin cells was enhanced in the presence of striatal neurons and numerous synaptic-like contacts between these two cell types were observed. Higher concentration of dopamine was also present in the co-culture medium as compared with those containing only chromaffin cells. The development of synapses between these two types of cells may give support to the functionality of transplants in human cases of Parkinson disease (PD).

Animals↗
PubMed2000

Identification of a 25-hydroxyvitamin D3 1alpha-hydroxylase gene transcription product in cultures of human syncytiotrophoblast cells.

Although accumulating data show that placenta is able to synthesize 1,25-dihydroxyvitamin D3, the presence of cytochrome P(450) enzyme capable of converting 25-hydroxyvitamin D3 (250HD(3)) to the biologically active form of vitamin D in this tissue, has not been yet clearly established. In this study, we have investigated the presence of 25-hydroxyvitamin D3 1alpha-hydroxylase (1alpha-(OH)ase) gene expression products in cultured human syncytiotrophoblast. Total RNA was isolated from cultured placental cells and subjected to Northern blots or RT-PCR by using 1alpha-(OH)ase-specific primers. The amplified complementary DNA fragments were analyzed by gel electrophoresis and nucleotide sequencing. Total RNA from kidney HEK 293 cells was subjected to reverse transcriptase reaction, and a 298-bp complementary DNA 1alpha-(OH)ase probe was generated by PCR. Primary cultures of human syncytiotrophoblasts exhibited 1alpha-(OH)ase activity, and a transcript for this gene could be demonstrated in these cells. Northern blot analysis revealed the presence of a 2.5-kb product, similar in size to that previously reported in kidney. RT-PCR analysis demonstrated the presence of a single transcript with nucleotide sequence identical to that previously reported for human 1alpha-(OH)ase complementary DNA clones. In addition, data are presented which suggest that differentiation of cytotrophoblast to the syncytial state was not necessary for this gene to be expressed, which may indicate a role of this enzyme all through pregnancy. The overall results of this study provide evidence for the presence of 1alpha-(OH)ase in the human placenta, suggesting that conversion of 25OHD(3) to 1,25-dihydroxyvitamin D3 in the trophoblast is most probably attributed to an enzymatic 1alpha-hydroxylation reaction.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed2000

[Chromosomal abnormalities in malignant hematologic diseases].

The inclusion of cytogenetic studies in the protocol study of patients with hematological malignant diseases is a very important contribution because these results contribute to establish better precision of diagnosis, prognostic and suggest adequate therapeutic management precociously. The Karyotypes of 200 patients between ages of 2 and 84 years, 56/200 acute lymphoblastic leukemia (ALL), 55/200 acute myeloid leukemia (AML), 63/200 chronic myeloid leukemia (CML), 20/200 myelodysplastic syndrome (MDS), and 6/200 chronic lymphocytic leukemia, (CLL), are analyzed. Certain differences were noted. In ALL, hyperdiploidy was the chromosomal abnormality more frequently observed and no cases of Ph+ chromosome were reported; with respect to AML, the autosomal monosomy and trisomy were the most frequent findings. MDS reports only one case with 5q deletion, 10% of patients presented trisomy 14, rarely reported. CML do no report any case with double Ph+ and only one case with i(17q); nevertheless, one case with 21q deletion was found, which is an unreported anomaly. CLL did not present any case with trisomy 12. These findings are discussed in the context of geographical heterogeneity of chromosomal abnormalities in leukemia, and emphasize the importance of continued epidemiological studies.

Acute Disease↗
PubMed1998

Use of low doses of clenbuterol to reduce incidence of ascites syndrome in broilers.

Beta-adrenergic agonists have been shown to be capable of improving growth performance in poultry when added to the feed at 1.0 ppm. However, no reference has been made concerning the cardiovascular responses when one of these agents is added to the feed at a lower concentration during the whole production cycle. The aim of this paper was to assess the effects on the ascites syndrome of 0.25 ppm clenbuterol in the feed, throughout 52 d, in broiler chicks. Results showed a lack of difference in growth and feed conversion rate between the untreated control groups and the experimental group. There were differences in mortality due to the ascites syndrome, abdominal fat:body weight ratio, and ventricular index. A statistically significant positive correlation was also found between ventricular index and mortality rate (r = 0.98). If adequate withdrawal times are ensured, the use of clenbuterol at 0.25 ppm is suggested to reduce mortality due to the ascites syndrome in broilers.

Adrenergic beta-Agonists↗
PubMed1997

Therapeutic efficacy of interferon alfa-2b in infants with life-threatening giant hemangiomas.

BACKGROUND: Because of their size and the possibility of complications, giant hemangiomas represent a therapeutic challenge. Various forms of treatment have been used, with variable results, including surgery, embolization, lasers, pentoxifylline, and corticosteroids. Interferon alfa has been used successfully to treat life-threatening hemangiomas, possibly by means of its antiangiogenic activity. OBSERVATIONS: We treated 7 infants with organ-interfering and/or life-threatening giant hemangiomas with subcutaneous injections of 3 million U/m2 per day of interferon alfa-2b during the first month and subsequently every 48 to 72 hours, depending on the evolution in each case. The treatment lasted from 3 to 12 months. In 2 patients, interferon alfa-2b was administered while prednisone therapy was being tapered. In all 7 patients, there was considerable reduction of the volume of the hemangiomas and remission of their complications. All patients presented with fever, neutropenia, and an increase in serum aminotransferase levels. The patients who received interferon alfa-2b and prednisone seemed to improve at a faster rate. CONCLUSIONS: Interferon alfa-2b is a good option for the treatment of patients with steroid-resistant, organ-interfering and/or life-threatening giant hemangiomas. In our experience, the adverse effects were transient and minor and did not require the interruption of the treatment.

Antineoplastic Agents↗
PubMed1995

Footshock facilitates the expression of aversively motivated memory in rats given post-training amygdala basolateral complex lesions.

We previously reported that increased training in an escape task partially attenuates the memory impairment produced by large amygdala lesions induced 1 week following training. The present study examined the effect of amount of preoperative training on the retention of rats with lesions restricted to the amygdala basolateral complex. Rats received 1 or 10 training trials in a footshock-motivated escape task and 1 week later sham lesions or neurotoxic lesions of the basolateral complex. Four days after recovery from the surgery they were tested for inhibitory avoidance retention and then 2 days later given continuous multiple trial inhibitory avoidance training (CMIA) in the same apparatus. The basolateral complex lesions significantly decreased the retention latencies of rats given 1 or 10 trials. However, following administration of footshock on the CMIA task, the performance of the lesioned rats reflected the degree of preoperative escape training. The basolateral complex lesions also increased open field locomotor activity, an effect that may have contributed to the shorter retention latencies in lesioned animals. These findings indicate that an intact amygdala basolateral complex is not critical for the retention of the escape training.

Amygdala↗
PubMed1995

Double-blind, randomized trial of one versus three prophylactic doses of synthetic surfactant in 826 neonates weighing 700 to 1100 grams: effects on mortality rate. American Exosurf Neonatal Study Groups I and IIa.

At 33 hospitals in the United States, a double-blind, randomized clinical trial was performed to compare one versus three prophylactic doses of synthetic surfactant in 700 to 1100 gm inborn infants. All 826 infants received an initial prophylactic dose of surfactant within 30 minutes of birth. Subsequently 410 infants received two doses of placebo (air) 12 and 24 hours later, and 416 infants received two additional doses of surfactant. By the age of 28 days, 70 infants who received one dose of surfactant and 40 infants who received three doses were dead, a 43% relative reduction in the mortality rate (30 fewer deaths; p = 0.002). By the age of 1 year after term, 87 infants who received one dose and 62 infants who received three doses were dead: a 29% relative reduction in the mortality rate (25 fewer deaths; p = 0.027). Infants who received three doses of surfactant required significantly less oxygen and less mean airway pressure for the first week of life. Necrotizing enterocolitis (9 vs 25 infants; p = 0.005), and use of high-frequency ventilation (13 vs 26 infants; p = 0.037); pancuronium (43 vs 62 infants; p = 0.045); and leukocyte transfusions (0 vs 4 infants; p = 0.042) were less frequent in the three-dose group, but air leak, bronchopulmonary dysplasia, intraventricular hemorrhage, patent ductus arteriosus, pulmonary hemorrhage, and infections were not different. These results indicate that physiologic findings, mortality rates, and probably morbidity rates are improved by two additional prophylactic doses of synthetic surfactant.

Bronchopulmonary Dysplasia↗
PubMed1991

The influence of environment and parasitism on the prevalence of asthma in two Venezuelan regions.

The point prevalence of bronchial asthma and the influence of environmental conditions among 100 individuals chosen from two Venezuelan regions, i.e., rural and urban, were investigated by history, routine laboratory tests, determination of total and specific IgE antibody to common allergens and spirometric tests. The point prevalence of bronchial asthma was 3.0% in rural subjects who were also highly parasitized by helminths and 3.6% in subjects from the urban region. A significative difference in skin responses to Dermatophagoides pteronnysinus was observed in urban asthmatics when compared with rural asthmatics. A similar response to selected allergens was found among both populations. The prevalence of infestation by Ascaris in rural asthmatics was high compared with that of rural controls. Total IgE levels were elevated for both populations, but significatively higher (p less than 0.05) for rural individuals. Results suggest a significative point prevalence of bronchial asthma in both regions, despite the helminth infestation of rural subjects. The effects of environmental factors, their concentration and time of exposure are considered as main factors responsible for allergic reactivity observed in the Venezuelan regions studied.

Asthma↗
PubMed1984

Should chronic transfusions be matched for antigens other than ABO and Rho(D)?

It has been recommended that red blood cell transfusions to patients with hemoglobinopathy or aplastic anemia be matched for antigens other than ABO and Rho(D). We studied 1,010 patients with disorders that often lead to repetitive transfusion. The frequency of transfused patients with clinically important antibodies was not significantly different among the disease groups except for those with lymphocytic leukemia. The frequency of multiple red cell antibodies was about 3% overall. Most antibodies (71%) developed early in the transfusion course, before the 15th transfusion. From the standpoints of frequency of alloimmunization, multiplicity of antibodies, and time course of antibody development, patients with hemoglobinopathy and aplastic anemia were not significantly different from other transfused patients. Matching for antigens other than ABO or Rho(D) might increase costs in our hospital by 40,000-370,000 dollars per year for these patients. Because morbidity or mortality due to these antibodies is rare, antigen matching for other than ABO and Rho(D) is not cost-effective.

ABO Blood-Group System↗
PubMed1983

Immune response to chronic red blood cell transfusion.

Patients receiving chronic transfusion for aplastic anemia or hemoglobinopathy are believed to be at high risk for developing red blood cell alloantibodies, while those undergoing chemotherapy for leukemia are believed to be at low risk. To test this hypothesis, we studied the acquisition of new alloantibodies in 703 transfused patients. While none of 99 patients with lymphocytic leukemia made new antibodies, patients with myelogenous leukemia (16%), hemoglobinopathy (29%), aplastic anemia (11%), gastrointestinal bleeding (11%) or renal failure (14%) made antibodies at statistically similar rates. Lymphocytic leukemia or its treatment is characterized by a lack of immunologic response to transfusion. Patients with hemoglobinopathy or aplastic anemia do not appear at statistically significant greater risk of alloimmunization than many other patients requiring chronic transfusion. Neither intensive chemotherapy for myelogenous leukemia nor the uremia of renal failure significantly suppress the formation of blood group antibodies.

Anemia, Aplastic↗
PubMed1980

[Broad beans (Vicia fava, L.) as an alternative source of protein in chick diets].

Three experiments were conducted to study the possibility of improving the nutritive value of broad beans (Vicia faba, L.) in poultry diets. In the first experiment, raw and autoclaved (1.0 kg/cm2/15 min) beans, with and without antibiotic supplementation, were studied. The results after 21 days showed no significant differences among treatments in regard to body weight. In feed conversion, however, a significant difference was observed when diets prepared with raw beans were supplemented with 20 ppm of flavomycin. In the second experiment raw and autoclaved beans were supplemented with 0, 10, and 20 ppm of virginiamycin and 200 and 400 ppm of flavomycin to study the effect of these two antibiotics. After 28 days, the results indicated no significant differences with antibiotic supplementation in either raw or autoclaved beans. However, a significant difference (P < 0.05) in body weight was found when beans were autoclaved. In the third experiment, two levels, 31 and 76% of raw and autoclaved beans, were included in the chick diets. The results in body weight, after 28 days, did not show any significant differences between raw and autoclaved beans fed at a 31% level. With the 76% level the autoclaved treatment, however, induced a significantly higher body weight than the diets containing raw beans.

Animal Feed↗