RESUMEN
We examined the effects of ascorbic acid supplementation on myosin-V, calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) immunoractivities in the myenteric neurons in aging rats. Male rats were divided into groups: young 90-day-old rats (E90), 345-day-old control rats (E345), 428-day-old control rats (E428), 90- to 345-day-old rats treated with ascorbic acid (1 g/L) (EA345), and 90- to 428-day-old rats treated with ascorbic acid (1g/L) (EA428). The quantitative results showed that aging reduced the number of myosin-V-immunoreactive neurons compared with young animals (E90). Ascorbic acid supplementation in the EA345 and EA428 groups increased the average area of myosin-V neurons by 24.6% and 24.1% compared with the E345 and E428 groups, respectively. When all groups were compared, we observed significant differences for the CGRP- and VIP-immunoractive varicosities of nerve fibers from myenteric neurons. Ascorbic acid supplementation had a neurotrophic effect on all neurons studied, suggesting a neuroprotective role.
Asunto(s)
Ácido Ascórbico/administración & dosificación , Péptido Relacionado con Gen de Calcitonina/metabolismo , Suplementos Dietéticos , Íleon/inervación , Inmunohistoquímica , Plexo Mientérico/efectos de los fármacos , Miosina Tipo V/metabolismo , Fibras Nerviosas/efectos de los fármacos , Fármacos Neuroprotectores/administración & dosificación , Péptido Intestinal Vasoactivo/metabolismo , Factores de Edad , Animales , Masculino , Plexo Mientérico/citología , Plexo Mientérico/metabolismo , Fibras Nerviosas/metabolismo , Ratas , Ratas WistarRESUMEN
The granular cell tumor is most often a benign neoplasm of uncertain origin. Four uterine granular cell tumors in control and treated female B6C3F1 mice were identified in chronic studies at the National Toxicology Program. Two tumors occurred in untreated control animals and 2 in treated animals receiving different compounds. Tissue sections were evaluated histologically and stained with hematoxylin and eosin, periodic acid-Schiff with diastase resistance, Masson's trichrome, toluidine blue, phosphotungstic acid-hematoxylin, and stained immunohistochemically with a panel of antibodies to muscle (desmin, alpha smooth muscle actin), neural (S-100, neuron specific enolase), epithelial (wide-spectrum cytokeratin), and macrophage (F4/80) markers. The main histomorphologic feature of tumor cells was the presence of abundant cytoplasmic eosinophilic granules that stained positive for periodic acid-Schiff with diastase resistance. Tumors varied in appearance and were comprised of sheets and nests of round to polygonal cells with distinct borders. Nuclei were hyperchromatic, pleomorphic, and centrally to eccentrically located and often contained single nucleoli. Occasional multinucleated giant cells were observed. Tumors were pale pink and homogeneous with trichrome stain and negative with toluidine blue. Three tumors had positive to weakly positive immunoreactivity for desmin, and 1 was positive for alpha smooth muscle actin. Expression of S-100, wide-spectrum cytokeratin, and neuron-specific enolase was negative for all tumors. Ultrastructurally, prominent electron-dense cytoplasmic granules were abundant and contained secondary lysosomes with heterogeneous lysosomal contents. The characteristics of these uterine granular cell tumors were suggestive of a myogenic origin.
Asunto(s)
Tumor de Células Granulares/veterinaria , Neoplasias Uterinas/veterinaria , Animales , Animales de Laboratorio , Cruzamientos Genéticos , Femenino , Tumor de Células Granulares/metabolismo , Tumor de Células Granulares/patología , Tumor de Células Granulares/ultraestructura , Inmunohistoquímica/veterinaria , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Microscopía Electrónica/veterinaria , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patología , Neoplasias Uterinas/ultraestructuraRESUMEN
When young people start a career in nursing, they have certain expectations about the profession. The intrinsic motivation of wanting to help plays the most important role. Does the nursing profession actually fulfill these expectations or will the everyday-routine of the profession soon disappoint the students? In the study presented, 166 nursing students were tested twice, once at the beginning of their education (Veit, 1996) and after having completed their second year of training. The comparison of the results of both surveys enables us to determine to which extent the expectations connected with the choice of a career were actually fulfilled. On the whole, the students participating in the survey were satisfied with their career choice. The degree to which their expectations were fulfilled, however, vary according to the different groups of students.
Asunto(s)
Actitud del Personal de Salud , Selección de Profesión , Satisfacción Personal , Estudiantes de Enfermería/psicología , Humanos , Estudios LongitudinalesRESUMEN
Phospholipid analogues were studied with regard to their cytostatic activity on different tumour cell lines and on murine bone marrow cells. Compounds compared for their activity were alkylglycero- and alkyl-phosphocholines with the corresponding serines and the alkylphosphocholines and -serines with the corresponding phosphono derivatives. Moreover, compounds containing cytidine 5'-diphosphate instead of the phospho (or phosphono-) choline or serine moiety were studied. rac-2-Chloro-2-deoxy-2-deoxy-1-0-hexadecyl-glycero-3-phosphocholine (cpd. Id), hexadecylphosphocholine (cpd. Ia) as well as hexadecylphosphonocholine (cpd. Ib) inhibited growth of tumour cells in suspension and monolayer culture and their colony and cluster formation in agar culture but not that of bone marrow cells. The exchange of choline for serine in these compounds results in the loss of this type of antitumour specificity. However, dodecylphospho-L-serine (cpd. IIc) is as specific as the choline derivatives Ia, b, d mentioned. Thus, for serine compounds the specificity for tumour cells might depend in a critical way on the length of the alkyl chain. The phosphono compounds Ib, IIb show almost the same activity as the corresponding compounds hexadecylphosphocholine (cpd. Ia) or hexadecylphosphoserine (cpd. IIa). The CDP-derivatives (IIIa, d, e, f) inhibited growth of tumour cells in suspension or monolayer cultures but not the colony and cluster formation in agar (i.e. they do not decrease the plating efficiency) from either tumour or bone marrow cells.
Asunto(s)
Antineoplásicos/farmacología , División Celular/efectos de los fármacos , Fosfolípidos/farmacología , Alquilación , Animales , Benzo(a)pireno/farmacología , Carcinoma de Ehrlich , Línea Celular Transformada , Ensayo de Unidades Formadoras de Colonias , Ensayos de Selección de Medicamentos Antitumorales , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/efectos de los fármacos , Humanos , Células KB , Leucemia Promielocítica Aguda , Ratones , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
The evidence that free oxygen radicals produced by polymorphonuclear neutrophils (PMN) participate in generation of reperfusion arrhythmias is well documented. The in vitro effect of selected antiarrhythmic drugs on PMN free radicals production was evaluated by luminol- (LuCL) and lucigenin- (LgCL) amplified chemiluminescence stimulated with opsonized zymosan (o.z.) and phorbol myristate acetate (PMA). Fast sodium channel inhibitors varied in the influence on PMN chemiluminescence: from an inhibition in all models studied by procainamide, to lack of an effect by mexiletine. Propafenone, similarly to ajmaline and verapamil, inhibited LuCL stimulated with PMA, as well as LgCL after stimulation with both PMA and o.z. Bretylium tosylate decreased LuCL stimulated with both inducers, with no effect on LgCL. Amiodarone in high concentrations inhibited both LuCL and LgCL. beta-blockers propranolol and practolol impaired LuCL stimulated with o.z., as well as LgCL induced with PMA, whereas alpha-blocker phentolamine inhibited LuCL and LgCL stimulated with both inducers. The drugs' effect on PMN free oxygen radicals production may constitute an additional mechanism of their activity.
Asunto(s)
Antiarrítmicos/farmacología , Neutrófilos/efectos de los fármacos , Oxígeno/metabolismo , Acridinas , Ajmalina/farmacología , Amiodarona/farmacología , Radicales Libres , Humanos , Lidocaína/farmacología , Mediciones Luminiscentes , Luminol , Neutrófilos/metabolismo , Propafenona/farmacología , Verapamilo/farmacologíaRESUMEN
All-trans-retinoic acid, hexamethylene bisacetamide and 5-azacytidine are inducers of granulocytic differentiation of HL-60 human myeloid leukaemic cells, which eventually leads to inhibition of cell proliferation. The effect of graded concentrations of all-trans-retinoic acid (RA) (1 nM-1 microM), hexamethylene bisacetamide (HMBA) (0.5-4 mM) and/or 5-azacytidine (5azaC) (1 nM-1 mM), alone and in combination with each other on colony formation and growth of HL-60 cells was studied in agar capillary clonogenic micro assays in order to identify new potential therapeutic regimens for elderly patients with acute myeloid leukaemia. ED90 concentrations, inducing 90% inhibition of colony formation for RA, HMBA and 5azaC, were 128 nM, 2.7 mM and 40 microM, respectively. The drug interactions between these differentiating agents were analysed by Berenbaum's general algebraic solution. The combinations: RA + HMBA, 5azaC + HMBA and RA + 5azaC were significantly synergistic in inhibiting HL-60 colony formation. Their interaction indices were 0.62, 0.83, and 0.97, respectively, at a specific effect level of 15%. The addition of 1 mM HMBA to 100 nM 5azaC- and 1 nM RA-treated cultures significantly increased the colony-formation inhibition from only 2.6% and 7.0% to 46.4%, and 43.1%, respectively. Also, HMBA showed marked synergism with RA and 5azaC in inhibiting colony growth. The interaction indices (I) of HMBA + RA and HMBA + 5azaC were 0.013 and 0.009, respectively, at the same specific level of 15%. Moreover, the triple combination of RA + HMBA + 5azaC showed synergism in inhibiting both the colony formation (I = 0.7) and colony growth (I = 0.4) at the same specific level of 15%. Since RA, HMBA and 5azaC were effective when administered alone in phase I clinical trials of myeloid leukaemic patients, their synergistic combinations could provide shorter and less toxic courses of treatment in elderly myeloid leukaemic patients. I is less than 1, = 1 or greater than 1 in synergistic, additive or antagonistic interactions, respectively.
Asunto(s)
Acetamidas/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Azacitidina/farmacología , Tretinoina/farmacología , Ensayo de Tumor de Célula Madre , Anciano , Diferenciación Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Sinergismo Farmacológico , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/patología , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
The effect of recombinant human GM-CSF on the cytostatic activity of the two cell cycle specific antileukaemic drugs, hydroxyurea and cytarabine, in HL-60 human myeloid leukaemic cells was studied in an agar capillary clonogenic micro assay. The ED90 concentrations which are the concentrations of hydroxyurea and cytarabine inducing a 90% maximum inhibition of colony formation and colony growth on day 7 in HL-60 cells were calculated from the logarithmic regression analysis of each dose response curve using the cricket graph version 1.3 program on an Apple Macintosh computer. Recombinant human GM-CSF significantly enhanced the cytostatic effect of hydroxyurea and cytarabine, and consequently reduced their ED90 concentrations. The present in vitro results provide a rationale for investigating the efficacy of combined recombinant human GM-CSF and hydroxyurea or cytarabine treatment in myeloid leukaemic patients.
Asunto(s)
Ciclo Celular/efectos de los fármacos , Citarabina/farmacología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Hidroxiurea/farmacología , División Celular/efectos de los fármacos , Línea Celular , Sinergismo Farmacológico , Humanos , Leucemia Promielocítica Aguda , Proteínas Recombinantes/farmacología , Análisis de Regresión , Ensayo de Tumor de Célula MadreRESUMEN
Undulin, a novel noncollagenous extracellular matrix protein, was isolated from skin and placenta. In polyacrylamide gels most of the unreduced protein migrates with Mr above 1,000,000 yielding bands A (Mr 270,000), B1 (Mr 190,000), and B2 (Mr 180,000) after reduction. Undulin is biochemically and immunochemically distinct from other previously characterized large matrix glycoproteins. Immunoblotting using monoclonal antibodies suggests that bands A and B are closely related. Electron microscopy reveals undulin as structures consisting of an approximately 80-nm-long-tail with a nodule on one end and with one or two shorter arms on the other. Ultrastructurally immunolabeled undulin is found mainly between densely packed mature collagen fibrils. Indirect immunofluorescence shows bundles of uniform wavy fibers in dense connective tissues superimposable on a subpopulation of type I collagen structures. This suggests that undulin serves a specific yet unknown function in the supramolecular organization of collagen fibrils in soft tissues.
Asunto(s)
Colágeno/aislamiento & purificación , Glicoproteínas/aislamiento & purificación , Aminoácidos/análisis , Animales , Animales Recién Nacidos , Anticuerpos , Anticuerpos Monoclonales , Carbohidratos/análisis , Colágeno/metabolismo , Colágeno/ultraestructura , Electroforesis en Gel de Poliacrilamida , Matriz Extracelular/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente , Glicoproteínas/metabolismo , Glicoproteínas/ultraestructura , Humanos , Immunoblotting , Macaca fascicularis , Ratones , Ratones Endogámicos BALB C/inmunología , Microscopía Electrónica , Peso Molecular , Mapeo Peptídico , Placenta/metabolismo , Embarazo , Unión Proteica , Piel/metabolismoRESUMEN
The mRNA coding for the rat liver S14 protein (Mr 17,000, pI 4.9) shows profound increases during postnatal development. In an effort to define the molecular basis for the postnatal rise in mRNAs14 we examined the chromatin organization of the S14 gene, its DNA methylation state, the hepatic expression of mRNAs14, and the in vitro S14 "run-on" activity prior to and after weaning at 21 days postpartum. In animals less than or equal to 15 days of age, the hepatic S14 gene is transcriptionally inactive, mRNAs14 levels are less than or equal to 0.5% of adult levels, and the chromatin organization within 11 kilobases of the 5' end of the S14 gene is similar to that found in tissues not expressing mRNAs14. From 18 to 22 days postpartum, the transcriptional activity of the S14 gene increases greater than or equal to 40-fold and mRNAs14 increases greater than or equal to 100-fold approaching adult levels of expression. Highly specific changes in S14 chromatin structure accompany gene activation. The formation of Hss-1 near the S14 cap site (-65 to -265 base pairs) and Hss-3 -3.3 kilobases upstream from the S14 cap site suggests that changes in DNA-protein interaction at these sites may function in both the tissue-specific and developmental regulation of S14 gene expression. The methylation studies suggest HhaI sites may be a cue for the tissue-specific expression of S14. However, the maintenance of hypermethylated HpaII sites throughout S14 gene activation argues against a role for these sites in either the tissue-specific or developmental regulation of S14 gene expression. These studies show that the principal molecular mechanism accounting for the major rise in mRNAs14 during postnatal development is activation of gene transcription and not stabilization of S14 RNA.