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Biomedical subjects

E Cano

Publications and source records attributed to E Cano.

At least 55 records · Page 3Linked to original sources
PubMed1990

Phenanthrylalkanoic acids, IV: Syntheses and antiinflammatory activity of 2-, 3-, and 9-phenanthryl- and 9-chloro-3-phenanthryl derivatives of propanoic acid.

The phenanthrylethanols 2a-d were obtained by reduction of the acetyl derivatives 1a-d and converted, through the phenanthrylethyl halides 3a-d and 4b, into the nitriles 5a-d, whose acid hydrolysis afforded the acids of the title, 6a-d. The antiinflammatory activity of these acids was measured on the carrageenin-induced edema and found as 1/3 (6a), 1/43 (6b), 1/5 (6c), and 1/7 (6d) of that of fenbufen.

Animals↗
PubMed1990

Induction of T cell activation by monoclonal antibodies specific for the transferrin receptor.

The effect of the monoclonal antibodies (mAb), FG 1/5, FG 1/6 and FG 2/12, specific for different epitopes of the transferrin receptor (TfR) on T cell activation was studied. mAb FG 1/6 but not FG 2/12 or FG 1/5 was able to induce T cell proliferation in presence of submitogenic doses of phorbol esters. The costimulatory effect of FG 1/6 was seen only with phorbol esters known to be activators of protein kinase C. This proliferation occurred at low concentration (0.5 micrograms/ml) of antibody, required the simultaneous presence of both stimuli, phorbol esters and FG 1/6, and was independent of the presence of accessory cells. Furthermore, FG 1/6 mAb was able to increase the rate of modulation of CD3 surface expression induced by phorbol esters. FG 1/6 induced interleukin (IL) 2 synthesis by normal and transformed T lymphocytes. In addition, anti-IL2 receptor antibodies inhibited FG 1/6 plus phorbol ester-induced proliferation. Our results indicate that FG 1/6 mAb may provide to the T cells complementary signals to protein kinase C and that this activation is mediated by the IL2/IL 2R pathway.

Animals↗
PubMed1990

Pharmacological effects of three phenylpropanoid glycosides from Mussatia.

The phenylpropanoid glycosides 1 (4-cinamoylmussatioside), 2 (4-dimethylcaffeoylmussatioside), and 3 (4-p-methoxycinnamoylmussatioside) isolated from the methanolic extract of Mussatia sp. showed inhibitory action on ADP-induced rat platelet aggregation. The order of activity was 1 greater than 2 greater than 3. This antiplatelet effect is likely to be related to the reported inhibition of cAMP-phosphodiesterase. On the other hand, compounds 1-3 had no effect on blood pressure and heart rate, on microbial growth, or on prostaglandin biosynthesis.

Animals↗
PubMed1990

[Uncinariasis in younger infants].

In order to determine the main clinical and laboratory manifestations associated with the infestation by an uncinaria during the first year of life, 42 children were studied from a group hospitalized between the years 1980 and 1985 in whom the main diagnosis at their time of leave from the hospital was parasitosis. Over 31 patients (74%) showed some degree of malnutrition, and severe in 24 of them (57% of the total). Clinical manifestations were mainly related to anemia (paleness, lack of air) and active intestinal bleeding (enterorrhagia, melena). Among the laboratory findings, 80% of the patients were shown to have anemia and in 24% of them, their hemoglobin levels were less than 5 g/dL, in more than half the anemia was normocytic normochromic. Also included are particularities concerning uncinariasis in the breast-feeding infant and some differences with the infection in the adult.

Ancylostomiasis↗
PubMed1989

Phenanthrylalkanoic acids, III: Syntheses and biological activities of 4-phenanthryl derivatives.

Reformatsky reactions between 2,3-dihydro-4(1H)-phenanthrenone (5) and ethyl alpha-bromoacetate or propanoate yield several unsaturated esters which, upon aromatization followed by saponification, lead to the 4-phenanthrylacetic (1) and 2-(4-phenanthryl)propanoic (2) acids. The analgesic and anti-inflammatory properties of 1 and 2 were measured and compared with those of Fenbufen.

Animals↗
PubMed1988

Biosynthesis of platelet-activating factor in glandular gastric mucosa. Evidence for the involvement of the 'de novo' pathway and modulation by fatty acids.

The biosynthesis of platelet-activating factor (PAF), a phospholipid autocoid with potent ulcerogenic properties that is produced in secretory exocrine glands by physiological secretagogues, was assessed in microsomal preparations of glandular gastric mucosa. For this purpose, 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (lyso-PAF):acetyl-CoA acetyltransferase (EC 2.3.1.67); the enzymes of the 'de novo' pathway: 1-O-alkyl-2-lyso-sn-glycero-3-phosphate (alkyl-lyso-GP):acetyl-CoA acetyltransferase and 1-O-alkyl-2-acetyl-sn-glycerol (alkylacetyl-G):CDP-choline cholinephosphotransferase (EC 2.7.8.16); and some enzymes involved in the catabolism of PAF and lyso-PAF were assayed. Only the enzymes of the 'de novo' pathway and small amounts of PAF acetylhydrolase, phospholipase A2 and a lysophospholipase D acting on either lipids could be detected in the gastric preparations, whereas lyso-PAF:acetyl-CoA acetyltransferase activity was undetectable. The specific activity of alkyl-lyso-GP:acetyl-CoA acetyltransferase in the gastric mucosa was about one-tenth of that found in spleen microsomes and its apparent Km for acetyl-CoA was 454 microM compared with 277 microM in spleen microsomes. Glandular mucosa homogenates contained preformed PAF at a concentration of 2.7 +/- 0.7 ng equivalents of PAF (hexadecyl)/mg of protein. When gastric microsomes were incubated with micromolar concentrations of fatty acids (arachidonic, palmitic and oleic) prior to the assay of dithiothreitol (DTT)-insensitive cholinephosphotransferase, a dose-dependent reduction in the formation of PAF was observed, arachidonic acid being the most potent inhibitor, followed by linoleic acid (only tested on spleen microsomes) and oleic acid. By contrast, 1,2-diolein and phosphatidylcholine (dipalmitoyl) showed no or little effect. These results indicate that glandular gastric mucosa can produce PAF through the 'de novo' pathway, and that fatty acids, especially unsaturated, can reduce that synthesis by modulating the expression of DTT-insensitive cholinephosphotransferase.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1988

Intracellular localization of platelet-activating factor synthesis in human neutrophils.

Human neutrophils were homogenized and fractionated on a continuous sucrose gradient to assess the subcellular location of acetyl-CoA: lyso-PAF acetyltransferase and of newly synthesized PAF (1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine). Acetyltransferase activity showed two subcellular locations in resting neutrophils. One of them cofractionated with plasma membrane and endoplasmic reticulum markers, whereas another major location corresponded to a region of the gradient enriched in tertiary granules. No PAF was detected in resting neutrophils, but PAF synthesis was induced by cell stimulation with ionophore A23187. Most of the newly synthesized PAF was found cell-associated, showing a bimodal subcellular distribution similar to that found for acetyltransferase activity in activated cells. PAF and acetyltransferase were located in a light membrane fraction, enriched in plasma membrane and endoplasmic reticulum, and in an ill-defined region of the gradient between the specific and azurophilic granules in A23187-stimulated cells. These data support the involvement of the acetyltransferase pathway in the synthesis of PAF induced by ionophore A23187, and demonstrate the synthesis and accumulation of newly synthesized PAF in a light membrane fraction as well as in an intracellular dense organelle upon neutrophil activation.

Acetyltransferases↗
PubMed1988

Role of paf-acether in the mediation of pathophysiological responses to aggregated immunoglobulins. Studies with the platelet-activating factor receptor antagonist BN 52021.

Sprague-Dawley rats were challenged with an intravenous (i.v.) infusion of soluble aggregates of immunoglobulin G. Animals receiving a dose of aggregates of 40 mg/kg showed a significantly reduced time of lysis of diluted blood clot, which paralleled the appearance in plasma of tissue-type plasminogen activator. These changes occurred about 5-10 min after the challenge, which is a more protracted time-course than that observed in response to paf-acether. A significant increase in serum levels of N-acetylglucosaminidase was also observed in the animals several minutes after challenge. Blood neutrophil count showed a 50% reduction that reached its maximum at 10 min and was followed by an overshoot after 30 min. In experiments in rats previously depleted of circulating PMN by treatment with vinblastine, no significant differences were observed in N-acetylglucosaminidase release as compared to non-treated animals. Since prior evidence indicated that endogenously generated paf-acether could be a mediator responsible for these changes, at least to some extent, the compound BN 52021, a specific antagonist of the paf-acether receptor was given to these animals prior to the challenge with the complexes. All the above mentioned responses were significantly reduced by BN 52021, which is in keeping with the hypothesis involving endogenous paf-acether release in the mediation of these changes. By contrast, BN 52021 did not interfere with the clearance of the aggregates from the circulation, which seems to be a beneficial mechanism to reduce immune-mediated tissue injury. These data extend the number of paf-acether mediated pathophysiological changes that can be observed in response to immune aggregates.

Acetylglucosaminidase↗
PubMedDate not supplied

Multivariate analysis results of radiotherapy for laryngeal cancer.

We assess the impact of radiotherapy in the treatment of laryngeal cancer and evaluate the value of the standard dose (linear quadratic plus time model) and other variables to predict tumor control and survival. Between 1972 and 1989, 80 patients with laryngeal cancer received comprehensive radiotherapy. Patients with stage I laryngeal glottic cancer (T1-N0-M0) were excluded from this study. Mean follow-up was 15 months (range 4 to 181). The mean age was 64.8 years (range 40 to 92). Standard dose varied from 32.65 to 81.81 Gy (mean 66.78). The 5-year overall survival and tumor-specific survival rates were 44.9 +/- 5.8% and 51.4 +/- 5.9%, respectively. Five-year local control and locoregional control rates were 66.4 +/- 5.7% and 61.9 +/- 5.8%, respectively. Multivariate analysis showed that local control was significantly predicted by T stage (p = .032), but not by standard dose (p = .906). Independently significant factors predicting tumor-specific survival included stage (p = .006), site (p = .019), and age (p = .001). Local control and survival were significantly predicted by the TNM-staging classification. The standard dose did not predict local recurrence or survival.

Adult↗
PubMedDate not supplied

[Endoscopic resection in early gastric cancer].

Development of therapeutic endoscopy has permitted the treatment of early gastric cancer (EGC) in its different macroscopic forms. In this paper we present 9 cases of EGC treated endoscopically in our Institution. We describe the criteria we follow to perform this procedure. The patients selected were of advanced age and high surgical risk. Seven cases were macroscopically Type I and two were Type IIa. According to localization six were proximal tumors (body and fundus) and three were located in the antrum. Six of the nine patients are alive after resection, one more than 6 years and 3 more than 3 years. Three patients died of ailments no related to cancer.

Aged↗
PubMedDate not supplied

[Histologic study of Helicobacter pylori in 265 consecutive gastric biopsies].

We evaluated 265 consecutive endoscopic gastric biopsies of subjects attending the gastric cancer mass survey that is taken place in the State of Tachira, Venezuela. They were 152 males and 113 females between 18 and 70 years of age. We established the prevalence of Helicobacter pylori in relation with histologic diagnosis and location of the lesions in the stomach. We performed hematoxylin eosin, Giemsa and Gimenez stains. The bacteria was identified in chronic non atrophic gastritis in 81% of the cases, in 76% of erosive gastritis, in 72% of gastric ulcers, in 36% of chronic atrophic gastritis and in 16% of neoplastic tissues. Helicobacter pylori was found in 82% of antral biopsies, and in 9% of the body, 7% of the fundus and 2% of the cardiac biopsies. From the total of 265 biopsies HP was positive in 172. The prevalence of this bacteria was 69.9% in this investigation.

Adolescent↗
PubMedDate not supplied

[Gastric cancer in hyperplasia polyps].

We present 3 cases of Early Gastric Cancer in 82 Hyperplastic Polyps (HP) resected endoscopically (3.6%) during the years 1985 to 1989, at the GI Cancer Center "Dr. Luis E. Anderson", San Cristobal, Venezuela. The diagnosis criteria followed were those of Nakamura, T and Nagayo T. This paper shows the possibility of malignant changes of these lesions, advising endoscopic resection of HP as a mean of treatment and in order to make a complete study of the polyps. We compare our data with existing bibliography, finding similitude in results.

Aged↗
PubMedDate not supplied

[Metastasis to lymph nodes in early gastric cancer].

The presence of metastasis in lymph nodes is one of the most important aspects to be evaluated in Early Gastric Cancer (EGC). In this paper we analyze the presence of that kind of metastasis in 70 EGC, in 66 patients studied in our Institute and surgically treated at the Central Hospital of San Cristobal. We found 3 cases with metastasis to perigastric (regional) lymph nodes (N1) and one case with extra perigastric lymph nodes metastasis (N3), that signify 5.7% of the total of all cases. We established the relationship of these metastasis and the following variables: macroscopic type, localization, size, depth of invasion within the gastric wall and the histological variety of the lesions. We found that the type IIa + IIc, the lesions located in the fundus, bigger that 3 cm, with invasion reaching the submucosa and histological differentiated (intestinal type), were the most important characteristics related with the presence of metastasis to the lymph nodes in our EGC.

Humans↗