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Biomedical subjects

J Andrade

Publications and source records attributed to J Andrade.

At least 55 records · Page 3Linked to original sources
PubMed1995

Decreased expression of Ras GTPase activating protein in human trophoblastic tumors.

The normally developing placenta undergoes extensive but regulated noninvasive cellular proliferation. Various proto-oncogenes and growth factors have been associated with the regulation of trophoblastic placental growth. Activation of some oncogenes and altered expression of growth factors have been demonstrated in trophoblastic tumors (hydatidiform mole and choriocarcinoma). The ras proto-oncogene plays a key role in the signal transduction cascade of activated growth factors, and is known to be activated or overexpressed in multiple tumor types. Ras GTPase activating protein (RasGAP), a major down-regulator of ras activity, is present at high levels in placenta. To assess the role that Ras-GAP plays in the development of trophoblastic tumors, we performed immunohistochemical analyses with anti RasGAP antibodies of normal placentas, hydatidiform moles, invasive moles, and malignant choriocarcinomas. Normal placentas and noninvasive hydatidiform mole displayed intense positive staining confined to trophoblasts, whereas no staining was observed in the trophoblasts of invasive moles or choriocarcinomas. Thus, there was an inverse correlation between expression levels of RasGAP protein and the invasive potential and malignant phenotype in human trophoblastic tumors. The data indicate that RasGAP may play a regulatory role in trophoblast proliferation and that abolishing its activity may be associated with malignant transformation of these cells.

Cell Transformation, Neoplastic↗
PubMed1994

Inhibitory effect of interferon-alpha on respiratory burst and glucose metabolism in phagocytic cells.

Anion superoxide (O2-) production and glucose metabolism was studied in murine macrophages following in vivo or in vitro treatment with human recombinant interferon-alpha 2b (IFN-alpha 2b). The PMA-dependent O2- production was inhibited by IFN-alpha 2b in a concentration- and time-dependent manner. NO2- production by macrophages in culture was slightly inhibited (about 16%) at 30 nM IFN-alpha and a clear decrease (35%) was obtained with 150 nM IFN-alpha. Low doses (0.3 and 3 nM IFN-alpha) had no effect. Also, IFN-alpha 2b inhibited lactate release and 3H2O production from [2-3H] and [3-3H]glucose in macrophages isolated after in vivo treatment for 24 h. The data support an inhibitory role of IFN-alpha in the metabolic activation of macrophages and suggest a putative mechanism for the inhibition of some macrophage functions as previously reported.

Animals↗
PubMed1993

Activation of peritoneal macrophages during the prediabetic phase in low-dose streptozotocin-treated mice.

Glucose metabolism and the production of O2- and NO2- have been studied in peritoneal macrophages from mice injected with 5 subdiabetogenic doses of streptozotocin. On day 12 after beginning of the treatment, peritoneal macrophages produced significantly higher amounts of lactate than macrophages from control mice. In addition, NO2- release and phorbol ester-induced O2- production were significantly augmented in macrophages from streptozotocin-treated mice. gamma-Interferon induced in a dose-dependent manner the activity of NO synthase only in macrophages from streptozotocin-treated mice. These data show for the first time that peritoneal macrophages from streptozotocin-treated mice are activated and produce effector molecules such as O2- and .NO which could participate in the destruction of pancreatic islets.

Amino Acid Oxidoreductases↗
PubMed1993

Short report: is spatial information encoded automatically in memory?

A dual-task paradigm was used to test Hasher and Zacks' (1979) hypothesis that spatial memory is automatic. Subjects saw two sets of 16 words each, the words being presented singly in random corners of a monitor screen. They were asked to remember the words and the corner in which each word was shown. In addition, subjects were given a concurrent task to perform. This task was either "easy" (counting aloud by ones) or "difficult" (counting aloud by sevens). Attention was focused either on the memory task or on the counting task. Word recognition was better when subjects carried out the easier competing counting task and when subjects concentrated mainly upon remembering the words and their positions. Contingent spatial memory was unaffected by either manipulation, supporting the hypothesis that spatial memory is automatic.

Adult↗
PubMed1993

A measure of consciousness and memory during isoflurane administration: the coherent frequency.

The coherent frequency (CF) of the auditory evoked response (AER) is derived using auditory clicks presented at frequencies in the range 5-47 Hz. CF and psychological performance were measured while seven subjects breathed isoflurane in doses increasing from 0% to 0.2%, 0.4% and 0.8% end-tidal concentration and then decreasing to 0%. With increasing doses of isoflurane, CF decreased and there was a decrease in within-list recognition (WLR) and category recognition (CR) scores. There was a correlation between changes in CF and WLR (P < 0.05) and between CF and category recognition (CR) (P < 0.05). A painful stimulus given in conjunction with 0.4% isoflurane caused an increase in CF, WLR and CR in some subjects. This did not reach statistical significance for the group as a whole, apart from the short word interval scores in the WLR which indicated an increase in attention (P < 0.01). Subjects did not respond with 0.8% isoflurane, either before or after painful stimulation. Reduction of end-tidal isoflurane from 0.8% to 0% caused an increase in the CF and improved performance on the psychological tests. A category generation task on recovery showed no evidence of implicit learning of words presented in conjunction with 0.8% isoflurane.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1992

Comparison of azoles against aspergilli in vitro and in an experimental model of pulmonary aspergillosis.

Current treatment modalities for bronchopulmonary aspergillosis are not very satisfying. We determined the in vitro activity of recently available azoles against Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger. Subsequently, these agents were evaluated in an animal model of bronchopulmonary aspergillosis using A. fumigatus as test organism. In vitro, detectable activity was only found for itraconazole (all minimal inhibitory concentrations, MICs, less than or equal to 3.2 micrograms/ml). The MICs for SCH39304 were greater than or equal to 12.8 micrograms/ml and greater than or equal to 25.6 micrograms/ml for ketoconazole and fluconazole. In vivo, amphotericin B was the most active agent tested, and SCH39304 was the most active azole in terms of survival and reduction in lung weight, followed by itraconazole. Ketoconazole and fluconazole did not improve survival nor reduce the lung weight of infected animals. We conclude, (1) that in vitro activity of azoles against aspergilli does not always correlate with in vivo activity; (2) that in vivo, SCH39304 was the most active azole tested, followed by itraconazole; (3) that for those agents for which data about effectiveness in human pulmonary aspergillosis are available (amphotericin B, ketoconazole, itraconazole) antifungal activity in our model corresponds to activity as seen in human beings, and (4) that SCH39304 and itraconazole are rational choices for clinical trials in human pulmonary aspergillosis.

Amphotericin B↗
PubMed1991

Urinary excretion of digoxin-like immunoreactive factor and arginine-vasopressin in hyper- and hypo-thyroid rats.

1. Urinary excretion of digoxin-like immunoreactive factor and arginine-vasopressin and other parameters related to salt and water metabolism were studied in hyper- and hypo-thyroid rats after different tests. 2. Urinary excretion of arginine-vasopressin was increased in hyperthyroid and reduced in hypothyroid rats with respect to controls, in response to water deprivation or a hypertonic saline load. 3. Control and hypothyroid rats showed the highest urinary excretion of digoxin-like immunoreactive factor after a hypertonic saline load. However, hyperthyroid rats had the highest urinary levels of digoxin-like immunoreactive factor under normal conditions. 4. From these results it is suggested that: (a) hyper- and hypo-thyroid rats exhibit hyper- and hypo-responsiveness of arginine-vasopressin secretion to osmotic stimuli, respectively; (b) an unidentified digoxin-like immunoreactive factor measured in unextracted rat urine may be related to diuresis and natriuresis in control and hypothyroid rats; however, dissociation between this factor and natriuresis is observed in hyperthyroid rats.

Animals↗
PubMed1991

Radiation-induced surface IgG modulation: protein kinase C involvement.

Although radiation-induced loss of surface IgG (s-IgG) expression on murine B cells is known to be dependent on intact energy metabolism and integrity of the cytoskeleton, the exact mechanism of this radiation effect is not known. Evidence reported here shows that inhibition of protein kinase C (PKC) by H-7 impairs the radiation-induced s-IgG modulation, whereas addition of HA-1004, which preferently inhibits c-AMP-dependent protein kinase, shows only minor effects. On the other hand PMA, a PKC activator, mimics the radiation effect, and H-7 but not HA-1004 inhibits the PMA-induced loss of s-IgG expression. Therefore it is suggested that PKC is involved in the modulation of s-IgG induced by irradiation on B cells. The possibility of membrane participation in this event is discussed.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

[Prevalence of smoking in young people and their parents. Important associations with education and occupation].

Rosario, with a million inhabitants, is the second major urban concentration in Argentina and serves as the commercial and industrial center for a large area. In view of the lack of information on the present prevalence of smoking in this area as for the country as a whole, a study was performed on random samples of young people and university students of medicine and economics, as well as on their parents. Information was obtained on their life smoking habits, education and occupation. The prevalence of the habit was higher: a) in men, both in the youngsters and their parents; b) in medical students than in those of the economic sciences; c) in parents with university education. The smoking habit of these subjects and parents was highly associated (p less than 0.001) in the sample of young people, although no association was found between the prevalence of smoking among university students and their parents. Peer smoking was the main factor influencing the onset of cigarette smoking given by 69% of the subjects. Knowledge of specific adverse health effects of smoking was poor. Attitudes toward restrictive measures were highly associated (p less than 0.001) with the non-smoker category. Based on these findings, we conclude that while there is a need for educational programs for the population in general, the university as a whole and specifically the school of medicine should implement a program to increase knowledge and awareness on this public health problem.

Adolescent↗
PubMed1990

Vascular reactivity in chronic Goldblatt two kidney-one clip hypertensive rats.

We studied the possible contribution of increased vascular reactivity in the chronic phase of Goldblatt two kidney-one clip hypertension. Vascular reactivity was evaluated in aortic strips from hypertensive rats (16 weeks after inducing hypertension) and age-matched control rats. The findings were: a) increased sensitivity to vasopressin in the aortic tissue of hypertensive rats, b) a similar response to angiotensin II, noradrenaline and KCl in hypertensive and control rats, and c) reduced maximal response to angiotensin II compared with other vasoconstrictors in both groups of rats. These results suggest a possible role for vasopressin in the chronic phase of this model of hypertension.

Angiotensin II↗
PubMed1990

Inactivity of terbinafine in a rat model of pulmonary aspergillosis.

In a model of bronchopulmonary aspergillosis terbinafine did not improve survival of experimental animals in doses up to 80 mg/kg/day despite adequate lung concentrations. Pretreatment and aerosolization of the compound were also ineffective. Terbinafine was markedly less active in vitro when serum was used instead of Yeast-Nitrogen-Glucose-broth. It is concluded that a lack of bioavailability in the presence of serum may explain the lack of activity of terbinafine in experimental aspergillosis.

Aerosols↗
PubMed1989

Influence of nutritional state on the disposal of orally and intramuscularly administered iodized oil to iodine repleted older children and adult women.

Iodinated oil (Ethiodol, 1 or 2 ml) was administered po or by im administration to adult women and older children in rural highland Ecuador who were either well nourished or malnourished to determine the effect of nutritional status on the disposal rate of iodine. These subjects resides in a region previously severely deficient in iodine, but this had been corrected in these subjects by prior administration of iodinated oil or by use of iodized salt or both. Malnutrition as determined by the conventional standards of height for age was associated with a significantly shortened retention time of the administered iodine, whether given po or im. The half life of retention was approximately half in the malourished of that in the well nourished. If these findings can be extrapolated to chronically iodine deficient subjects, then malnourished populations in need of iodine supplementation should either receive higher dosages than those conventionally employed or more frequent dosage.

Adolescent↗
PubMed1988

Epidemiological aspects of leptospirosis in a slum area in the city of Rio de Janeiro, Brazil. Search for leptospires and specific antibodies in rodents.

101 Rattus norvegicus and 3 Mus musculus were captured in an urban slum of Rio de Janeiro city and examined for leptospiral infection. Direct examination of urine, serology (microagglutination) and culture together gave a positivity rate of 39%. Separately direct examination and serology gave positivity rates of 13% and 36% respectively. Serogroup Icterohaemorrhagiae predominated in the serological tests. Leptospires were isolated from 24 of the 104 rodents (23%), but 4 cultures died. The remaining 20 were identified as members of the Icterohaemorrhagiae serogroup, and 5 were further identified as serovar copenhageni. Human leptospiral infection, mainly caused by Icterohaemorrhagiae, is endemic in Rio de Janeiro city, and rodents are a major source of the disease.

Agglutination Tests↗
PubMed1988

MIC and fungicidal activity of terbinafine against clinical isolates of Aspergillus spp.

Terbinafine and amphotericin B MICs for 90% of strains tested were 1.6 and 0.4 micrograms/ml against Aspergillus fumigatus (16 strains), 0.8 and 3.2 micrograms/ml against Aspergillus flavus (10 strains), and 0.4 and 1.6 micrograms/ml against Aspergillus niger (10 strains), respectively. For all species tested, the minimal inhibitory and fungicidal concentrations for 90% of strains of both drugs were identical and the inoculum size did not have a major effect on the results.

Amphotericin B↗