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1.
Eur J Neurol ; 27(4): 709-715, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31769567

RESUMEN

BACKGROUND AND PURPOSE: The aim was to assess the value of insoluble PABPN1 muscle fibre nuclei accumulation in the diagnosis of atypical cases of oculopharyngeal muscular dystrophy (OPMD). METHODS: Muscle biopsies from a selected cohort of 423 adult patients from several Italian neuromuscular centres were analysed by immunofluorescence: 30 muscle biopsies of genetically proven OPMD, 30 biopsies from patients not affected by neuromuscular disorders, 220 from genetically undiagnosed patients presenting ptosis or swallowing disturbances, progressive lower proximal weakness and/or isolated rimmed vacuoles at muscle biopsy and 143 muscle biopsies of patients affected by other neuromuscular diseases. RESULTS: The detection of insoluble nuclear PABPN1 accumulation is rapid, sensitive (100%) and specific (96%). The revision of our cohort allowed us to discover 23 new OPMD cases out of 220 patients affected with nonspecific muscle diseases. CONCLUSIONS: Oculopharyngeal muscular dystrophy is often misdiagnosed leading to diagnosis delay, causing waste of time and resources. A great number of these cases present symptoms and histological findings frequently overlapping with other muscle diseases, i.e. inclusion body myositis and progressive external ophthalmoplegia. PABPN1 nuclear accumulation is a reliable method for diagnostic purposes and it is safe and useful in helping pathologists and clinicians to direct genetic analysis in the case of suspected OPMD, even when clinical and histological clues are deceptive.


Asunto(s)
Núcleo Celular/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular Oculofaríngea/diagnóstico , Proteína I de Unión a Poli(A)/metabolismo , Núcleo Celular/patología , Técnica del Anticuerpo Fluorescente , Humanos , Músculo Esquelético/patología , Distrofia Muscular Oculofaríngea/metabolismo , Distrofia Muscular Oculofaríngea/patología
2.
Neuroscience ; 159(2): 842-9, 2009 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-19186208

RESUMEN

The En2 gene, coding for the homeobox-containing transcription factor Engrailed-2 (EN2), has been associated to autism spectrum disorder (ASD). Due to neuroanatomical and behavioral abnormalities, which partly resemble those observed in ASD patients, En2 knockout (En2(-/-)) mice have been proposed as a model for ASD. In the mouse embryo, En2 is involved in the specification of midbrain/hindbrain regions, being predominantly expressed in the developing cerebellum and ventral midbrain, and its expression is maintained in these structures until adulthood. Here we show that in the adult mouse brain, En2 mRNA is expressed also in the hippocampus and cerebral cortex. Hippocampal En2 mRNA content decreased after seizures induced by kainic acid (KA). This suggests that En2 might also influence the functioning of forebrain areas during adulthood and in response to seizures. Indeed, a reduced expression of parvalbumin and somatostatin was detected in the hippocampus of En2(-/-) mice as compared to wild-type (WT) mice, indicating an altered GABAergic innervation of limbic circuits in En2(-/-) mice. In keeping with these results, En2(-/-) mice displayed an increased susceptibility to KA-induced seizures. KA (20 mg/kg) determined more severe and prolonged generalized seizures in En2(-/-) mice, when compared to WT animals. Seizures were accompanied by a widespread c-fos and c-jun mRNA induction in the brain of En2(-/-) but not WT mice. Long-term histopathological changes (CA1 cell loss, upregulation of neuropeptide Y) also occurred in the hippocampus of KA-treated En2(-/-) but not WT mice. These findings suggest that En2(-/-) mice might be used as a novel tool to study the link between epilepsy and ASD.


Asunto(s)
Susceptibilidad a Enfermedades , Agonistas de Aminoácidos Excitadores/toxicidad , Ácido Kaínico/toxicidad , Proteínas del Tejido Nervioso/deficiencia , Convulsiones/inducido químicamente , Convulsiones/genética , Animales , Encéfalo/anatomía & histología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Proteínas de Homeodominio/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas del Tejido Nervioso/genética , Parvalbúminas/metabolismo , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , ARN Mensajero/metabolismo , Tiempo de Reacción/efectos de los fármacos , Somatostatina/metabolismo , Factores de Tiempo
3.
Sci Rep ; 9(1): 19988, 2019 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-31882707

RESUMEN

In percutaneous interventions, reaching targets located deep inside the body with minimal tissue damage and patient pain requires the use of long and thin needles. However, when pushed through a solid substrate, a structure with a high aspect ratio is prone to buckle. We developed a series of multi-element needles with a diameter smaller than 1 mm and a length larger than 200 mm, and we experimentally evaluated the performance of a bio-inspired insertion mechanism that prevents needle buckling of such slender structures. The needles consisted of Nitinol wires and advance into a substrate by pushing the wires forward one after the other, followed by pulling all the wires simultaneously backward. The resulting net push force is low, allowing the needles to self-propel through the substrate. We investigated the effect of the needle design parameters (number of wires and their diameter) and substrate characteristics (stiffness and number of layers) on the needle motion. Three needle prototypes (consisting of six 0.25-mm wires, six 0.125-mm wires, and three 0.25-mm wires, respectively) were inserted into single- and multi-layered tissue-mimicking phantoms. The prototypes were able to move forward in all phantoms without buckling. The amount of needle slip with respect to the phantom was used to assess the performance of the prototypes. The six-wire 0.25-mm prototype exhibited the least slip among the three prototypes. Summarizing, we showed that a bio-inspired motion mechanism prevents buckling in very thin (diameter <1 mm), long (length >200 mm) needles, allowing deep insertion into tissue-mimicking phantoms.

4.
Int J Immunopathol Pharmacol ; 21(2): 319-24, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18547475

RESUMEN

The aim of the present study is to evaluate the role of CRP and Total Cholesterol (TC) in patients suffering from type I Bipolar Disorder (BD-I). Moreover, the goal is to elucidate possible CRP and TC differences in different phases of BD-I: acute mania, euthymia and bipolar depression. Medical records of 90 BD-I patients (30 patients with acute mania, 30 in euthymic state, full remission, and 30 in depressive phase) were reviewed to evaluate serum CRP and TC levels. Laboratory data of 30 healthy controls were also obtained. The scores of Young Mania Rating Scale (YMRS), Bech-Rafaelsen Manic Rating Scale (BRMRS) and Hamilton Rating Scale for Depression (HAM-D) were evaluated. CRP levels were higher in acute mania and depressive phase subgroups when compared to healthy controls. CRP was positively associated with BRMRS and YMRS scores in acute mania and with HAM-D in depressive phase subgroups. TC levels were lower in all clinical groups compared to controls. TC levels were negatively correlated to BRMRS, YMRS and HAM-D. In conclusion, the results of the present study support the notion that CRP and TC may be altered in patients with BP-I.


Asunto(s)
Trastorno Bipolar/sangre , Proteína C-Reactiva/metabolismo , Colesterol/sangre , Adiposidad , Adolescente , Adulto , Trastorno Bipolar/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Estudios Retrospectivos
5.
Bioinspir Biomim ; 13(1): 016006, 2017 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-29019464

RESUMEN

Flexible steerable needles have the potential to allow surgeons to reach deep targets inside the human body with higher accuracy than rigid needles do. Furthermore, by maneuvering around critical anatomical structures, steerable needles could limit the risk of tissue damage. However, the design of a thin needle (e.g. diameter under 2 mm) with a multi-direction steering mechanism is challenging. The goal of this paper is to outline the design and experimental evaluation of a biologically inspired needle with a diameter under 2 mm that advances through straight and curved trajectories in a soft substrate without being pushed, without buckling, and without the need of axial rotation. The needle design, inspired by the ovipositor of parasitoid wasps, consisted of seven nickel titanium wires and had a total diameter of 1.2 mm. The motion of the needle was tested in gelatin phantoms. Forward motion of the needle was evaluated based on the lag between the actual and the desired insertion depth of the needle. Steering was evaluated based on the radius of curvature of a circle fitted to the needle centerline and on the ratio of the needle deflection from the straight path to the insertion depth. The needle moved forward inside the gelatin with a lag of 0.21 (single wire actuation) and 0.34 (double wire actuation) and achieved a maximum curvature of 0.0184 cm-1and a deflection-to-insertion ratio of 0.0778. The proposed biologically inspired needle design is a relevant step towards the development of thin needles for percutaneous interventions.


Asunto(s)
Genitales Femeninos/anatomía & histología , Agujas , Aleaciones , Animales , Módulo de Elasticidad , Diseño de Equipo , Femenino , Gelatina , Oviposición , Fantasmas de Imagen , Rotación , Avispas/anatomía & histología
6.
J Breath Res ; 11(4): 047110, 2017 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-29052557

RESUMEN

The analytical performances of needle trap micro-extraction (NTME) coupled with gas chromatography-tandem mass spectrometry were evaluated by analyzing a mixture of twenty-two representative breath volatile organic compounds (VOCs) belonging to different chemical classes (i.e. hydrocarbons, ketones, aldehydes, aromatics and sulfurs). NTME is an emerging technique that guarantees detection limits in the pptv range by pre-concentrating low volumes of sample, and it is particularly suitable for breath analysis. For most VOCs, detection limits between 20 and 500 pptv were obtained by pre-concentrating 25 ml of a humidified standard gas mixture at a flow rate of 15 ml min-1. For all compounds, inter- and intra-day precisions were always below 15%, confirming the reliability of the method. The procedure was successfully applied to the analysis of exhaled breath samples collected from forty heart failure (HF) patients during their stay in the University Hospital of Pisa. The majority of patients (about 80%) showed a significant decrease of breath acetone levels (a factor of 3 or higher) at discharge compared to admission (acute phase) in correspondence to the improved clinical conditions during hospitalization, thus making this compound eligible as a biomarker of HF exacerbation.


Asunto(s)
Pruebas Respiratorias/instrumentación , Pruebas Respiratorias/métodos , Espiración , Cromatografía de Gases y Espectrometría de Masas/métodos , Insuficiencia Cardíaca/diagnóstico , Agujas , Compuestos Orgánicos Volátiles/análisis , Adulto , Anciano , Anciano de 80 o más Años , Dióxido de Carbono/análisis , Femenino , Humanos , Límite de Detección , Masculino , Persona de Mediana Edad , Análisis de Componente Principal , Reproducibilidad de los Resultados
7.
Eur J Cell Biol ; 67(3): 209-17, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7588877

RESUMEN

Using anti-myosin antibodies, standard immunocytochemical techniques in conjunction with confocal scanning laser microscopy and colloidal gold immunoelectron microscopy we compare changes in the distribution patterns of myosin during the early stages of pollen hydration, germination, tube growth, and myosin associated with isolated vegetative nucleus and the generative cell in Nicotiana tabacum L. Furthermore, on the Western blots of pollen tube proteins, the antimyosin antibodies crossreact only with one polypeptide of approximately 174 kDa. Confocal immunofluorescence microscopy reveals that in hydrated pollen, myosin is discretely associated with the cytoplasmic organelles and numerous punctate structures present in the center of the pollen. Within 30 min following transfer of pollen into the germination medium, that is, with the onset of germination, the centrally located punctate structures are displaced, and we find accumulation of myosin-associated organelles towards one of the germinal apertures from which the pollen tube would emerge. Subsequently, after 45 min of germination with the emergence of germination structure, few punctate structures are detected in the vegetative cytoplasm while intense immunostain is detected just below the plasma membrane of the emerging pollen tube tip. In the older parts of both short and long pollen tubes after 90 to 120 min of pollen germination, few fluorescent structures were found in the pollen tubes, however, numerous punctate fluorescent spots were concentrated in the tip region over a distance of 2 to 3 microns below the plasma membrane of the tube tip. This is further substantiated by colloidal gold immunoelectron microscopy wherein clusters of gold particles are associated with vesicle-like structures in the tip region of the pollen tubes.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Germinación , Miosinas/aislamiento & purificación , Nicotiana/ultraestructura , Plantas Tóxicas , Polen/ultraestructura , Western Blotting , Núcleo Celular/ultraestructura , Técnica del Anticuerpo Fluorescente , Oro , Procesamiento de Imagen Asistido por Computador , Rayos Láser , Microscopía Confocal , Microscopía Inmunoelectrónica , Miosinas/inmunología , Polen/química , Polen/crecimiento & desarrollo , Nicotiana/química , Nicotiana/citología , Agua
8.
J Clin Endocrinol Metab ; 74(4): 946-9, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1312543

RESUMEN

Mineralocorticoid effector mechanisms were evaluated in 29 patients with preeclampsia and in 25 uncomplicated pregnancies by measurement of plasma aldosterone, levels of mineralocorticoid receptor (MR) in mononuclear leucocytes, and subtraction potential difference (SPD; rectal minus oral values). Mean values for plasma aldosterone were not different between the two groups, but significant differences were observed for MR (preeclampsia, 81 +/- 44 receptors/cell; controls, 306 +/- 168) and SPD (preeclampsia, 65 +/- 7 mV; controls, 12 +/- 5 mV). In six cases we determined MR, plasma aldosterone, and SPD in patients with preeclampsia before and 3 months after delivery. MR were reduced before delivery (96 +/- 27 receptors/cell), and SPD increased (64 +/- 8 mV), with both parameters normalizing after delivery (MR, 242 +/- 79; SPD, 14.0 +/- 4 mV). Aldosterone levels returned to normal nonpregnant values after delivery. These data suggest an important role for abnormalities in mineralocorticoid effector mechanisms in the etiology of preeclampsia and could be an useful marker for diagnosis.


Asunto(s)
Mineralocorticoides/fisiología , Preeclampsia/fisiopatología , Adulto , Aldosterona/sangre , Presión Sanguínea , Femenino , Humanos , Leucocitos Mononucleares/química , Leucocitos Mononucleares/ultraestructura , Preeclampsia/sangre , Preeclampsia/etiología , Embarazo , Receptores de Mineralocorticoides , Receptores de Esteroides/análisis
9.
J Steroid Biochem Mol Biol ; 45(1-3): 191-4, 1993 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8481346

RESUMEN

We have measured plasma aldosterone, plasma cortisol, and glucocorticoid and mineralocorticoid receptors in mononuclear leukocytes in 54 healthy aged subjects (60-97 years old) and in a group of 21 controls (21-50 years old). In addition all parameters and age were plotted for correlation. Plasma cortisol was significantly higher in the aged group (346 +/- 140 nmol/l) than in controls (260 +/- 120). Mean plasma aldosterone was not different in the two groups. Both Type I and II receptors in mononuclear leukocytes were lower in the aged group than in controls (Type I 198 +/- 96 and 272 +/- 97 receptors per cell; Type II 1738 +/- 801 and 3339 +/- 918 receptors per cell). A direct correlation was found between cortisol and age and between Type I and II receptors in aged subjects, and between cortisol and Type I receptors, and cortisol and Type II receptors in controls. When all subjects are plotted together, a direct correlation was observed between cortisol and age and between Type I and II receptors, and an inverse correlation between age and Type I and age and Type II receptors. We conclude that the parallel reduction of both Type I and II receptors with age is not due to prior cortisol increase, but the increase of plasma cortisol can be considered the result of age-dependent involution of these receptors.


Asunto(s)
Envejecimiento/sangre , Receptores de Glucocorticoides/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Aldosterona/sangre , Glucocorticoides/sangre , Humanos , Hidrocortisona/sangre , Persona de Mediana Edad , Mineralocorticoides/sangre
10.
Steroids ; 58(12): 611-3, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8116017

RESUMEN

Mean mineralocorticoid receptor number in mononuclear leukocytes of patients with increased plasma aldosterone (Conn's syndrome, nephrovascular hypertension, preeclampsia) is lower than in controls and this reduction could be the consequence of a down-regulation of the receptor. A similar pattern is evident also in situations of excess of other mineralocorticoids (Cushing's syndrome, chronic licorice ingestion). In essential hypertension 20% of cases have reduced number of mineralocorticoid receptors in mononuclear leukocytes without increase of aldosterone and normal serum potassium. We postulate that in some cases with essential hypertension the reduction of mineralocorticoid receptors is an index of mineralocorticoid excess due to mineralocorticoids other than aldosterone.


Asunto(s)
Hipertensión/metabolismo , Receptores de Mineralocorticoides/metabolismo , Adolescente , Adulto , Síndrome de Cushing/metabolismo , Dexametasona/uso terapéutico , Femenino , Humanos , Hiperaldosteronismo/tratamiento farmacológico , Hiperaldosteronismo/metabolismo , Hipertensión Renal/metabolismo , Leucocitos Mononucleares/metabolismo , Persona de Mediana Edad , Preeclampsia/metabolismo , Embarazo
11.
Toxicol In Vitro ; 8(6): 1277-83, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20693100

RESUMEN

The exposure of 3T3 mouse fibroblasts to vinyl-4-cyclohexene dioxide (VCD), a compound used as a chemical intermediate and as a reactive diluent for diepoxides and epoxy resins, induces changes in cellular shape and cytoplasmic organization. Toxicological effects on the cytoskeletal elements were investigated by culturing 3T3 cells in medium containing VCD for increasing times (15, 30, 60 and 180 min). The immunofluorescence investigations demonstrated that both vimentin-containing intermediate filaments and microtubules were compromised by the treatment in a time-dependent manner. Increasing the duration of exposure to VCD increased cellular damage.

13.
Am J Physiol ; 262(4 Pt 1): E464-6, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1566834

RESUMEN

Plasma cortisol and aldosterone levels and number of related receptors in mononuclear leukocytes were measured in 49 healthy aged subjects (62-97 yr) and in 21 adult controls (21-50 yr). In all subjects, in addition, lymphocyte subsets were determined as an index of corticosteroid action. The mean number of type I and type II receptors was significantly lower in aged subjects than in controls (respectively, 198 +/- 96 and 272 +/- 97 receptors/cell for type I, and 1,794 +/- 803 and 3,339 +/- 918 for type II receptors). Plasma aldosterone and cortisol and lymphocyte subsets were not different in the two groups. All of the parameters were also tested for correlation, and a significant inverse correlation was found between age and type I and type II receptors when all subjects were plotted and between aged and CD4 and age and CD4/CD8 in the aged group. These data show that aged subjects have reductions of corticosteroid receptors that are not associated with increase of related steroids and that this situation probably represents a concomitant of the normal aging process.


Asunto(s)
Envejecimiento/metabolismo , Subgrupos Linfocitarios/citología , Monocitos/metabolismo , Receptores de Glucocorticoides/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Aldosterona/sangre , Humanos , Persona de Mediana Edad , Monocitos/citología , Receptores de Glucocorticoides/química
14.
Pharmatherapeutica ; 2(8): 504-8, 1981.
Artículo en Inglés | MEDLINE | ID: mdl-7019929

RESUMEN

Efficacy and tolerance of a new preparation of pure glucosamine sulphate, in injectable and oral form, were investigated in 30 patients with osteoarthrosis. Two groups of in-patients with chronic degenerative articular disorders received daily for 7 days either 400 mg glucosamine sulphate or a piperazine/chlorbutanol combination by intravenous or intramuscular injection. During the 2 following weeks, the patients receiving glucosamine had oral glucosamine capsules (6 x 250 mg daily); the other group had placebo. Efficacy was tested by semi-quantitative scoring of pain at rest and during active and passive movements, as well as limitation of articular function, before and after 7 and 21 days of treatment. Patients were positively questioned daily for possible intolerance symptoms. Haematology, circulatory data and urine analysis were tested before and after treatment. During both initial parenteral treatments, each symptom significantly improved, but to a faster and greater extent in the group treated with glucosamine. During the maintenance period, a further improvement was recorded in the patients treated with glucosamine, whereas in those on placebo the symptom scores increased almost to the pre-treatment level. This was considered the major difference between basic therapy, such as with glucosamine, as purely symptomatic treatment. Clinical and biological tolerance were excellent with both treatments, and no definitely drug-related complaints were recorded. It is suggested that parenteral and/or oral treatment with pure glucosamine sulphate should be considered as basic therapy for the management of primary or secondary degenerative osteoarthrosis disorders.


Asunto(s)
Glucosamina/uso terapéutico , Osteoartritis/tratamiento farmacológico , Anciano , Ensayos Clínicos como Asunto , Femenino , Glucosamina/efectos adversos , Humanos , Masculino , Persona de Mediana Edad
15.
J Endocrinol Invest ; 13(10): 847-8, 1990 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2096161

RESUMEN

Four cases of pseudohyperaldosteronism due to chronic ingestion of liquorice-containing laxatives are described. All patients had hypertension and hypokalemia with suppression of plasma renin activity and aldosterone; the diagnosis was based only on retrospective grounds. In patients with hypokalemia and hypertension a possibility of such a cause must be excluded to avoid unnecessary diagnostic procedures.


Asunto(s)
Catárticos/efectos adversos , Glycyrrhiza , Hiperaldosteronismo/inducido químicamente , Plantas Medicinales , Adulto , Anciano , Aldosterona/sangre , Combinación de Medicamentos , Femenino , Humanos , Hiperaldosteronismo/sangre , Hiperaldosteronismo/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Extractos Vegetales/efectos adversos , Aceites de Plantas/efectos adversos , Potasio/sangre , Renina/sangre , Extracto de Senna/efectos adversos , Espironolactona/uso terapéutico
16.
J Cell Sci ; 108 ( Pt 3): 1117-25, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7622598

RESUMEN

Nicotiana tabacum pollen tubes contain two high molecular weight polypeptides (about 400 kDa), which are specifically expressed during pollen germination and pollen tube growth in BK medium. The high molecular weight doublet resembles the dynein heavy chains in some biochemical properties. Sedimentation profiles of pollen tube extracts show that the high molecular weight bands have sedimentation coefficients of 22 S and 12 S, respectively. ATPase assay of sedimentation fractions shows an activity ten times higher when stimulated by the presence of bovine brain microtubules in fractions containing the 22 S high molecular weight polypeptide. Both these high molecular weight polypeptides can bind microtubules in an ATP-dependent fashion. A mouse antiserum to a synthetic peptide reproducing the sequence of the most conserved ATP-binding site among dynein heavy chains recognized the two high molecular weight polypeptides. Therefore these polypeptides have sequences immunologically related to the ATP binding sites of dynein heavy chains.


Asunto(s)
Dineínas/química , Nicotiana/química , Proteínas de Plantas/química , Plantas Tóxicas , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/metabolismo , Secuencia de Aminoácidos , Animales , Anticuerpos , Sitios de Unión , Encéfalo/metabolismo , Bovinos , Dineínas/genética , Dineínas/metabolismo , Inmunoquímica , Técnicas In Vitro , Microtúbulos/metabolismo , Datos de Secuencia Molecular , Peso Molecular , Péptidos/síntesis química , Péptidos/química , Péptidos/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/química , Nicotiana/genética , Nicotiana/metabolismo
17.
J Endocrinol Invest ; 12(5): 337-41, 1989 May.
Artículo en Inglés | MEDLINE | ID: mdl-2671110

RESUMEN

Carbenoxolone is a derivative of glycyrrhetinic acid used for the treatment of peptic ulcer and gastritis, with salt and water retention a very common side-effect. To investigate this drug-induced pseudohyperaldosteronism we have studied 6 male volunteers before, during and after treatment with carbenoxolone for 7 days. Serum, urinary and sweat electrolytes values were consistent with a mineralocorticoid-like effect of drug administration. PRA was suppressed, and plasma cortisol and aldosterone progressively decreased over treatment. We have also determined by radioreceptor assay the plasma levels of factors which bind to mineralocorticoid receptors in rat kidney cytosol. The levels of these factors were decreased significantly at day 3 of treatment, suggesting a local renal effect of carbenoxolone to amplify endogenous steroid action. At day 7 the radioreceptor assay values were still decreased but significantly higher than at day 3, suggesting in addition a direct mineralocorticoid effect of the drug. We conclude that the drug is initially effective by amplifying the effect of endogenous steroids, and then when the plasma concentrations of the drug or its metabolites reach a higher plasma concentration, there may also be in addition a direct mineralocorticoid-like effect.


Asunto(s)
Carbenoxolona/efectos adversos , Ácido Glicirretínico/análogos & derivados , Hiperaldosteronismo/inducido químicamente , Adulto , Aldosterona/metabolismo , Peso Corporal/efectos de los fármacos , Citosol/metabolismo , Electrólitos/metabolismo , Humanos , Hidrocortisona/metabolismo , Hiperaldosteronismo/metabolismo , Riñón/metabolismo , Masculino , Mineralocorticoides/metabolismo , Mineralocorticoides/fisiología , Renina/metabolismo , Tetrahidrocortisol/orina , Tetrahidrocortisona/orina
18.
Zygote ; 2(1): 63-8, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7881918

RESUMEN

Using monoclonal anti-calmodulin antibodies in conjunction with confocal scanning laser microscopy we have analysed the spatial variations in the distribution pattern of calmodulin (CaM) during the sequential events of pollen hydration, germination and tube growth in Nicotiana tabacum. These immunocytochemical observations have been complemented by immunochemical studies wherein the anti-calmodulin antibody raised against pea CaM recognises a polypeptide of c. 18 kDa in the pollen extracts. Digitisation of confocally acquired optical sections of immunofluorescence images reveals that in hydrated pollen a high level of CaM is consistently present in the region of the germinal apertures. Subsequently, with the onset of germination a high CaM concentration was found associated with the plasma membrane of the germination bubble and in the cytoplasm in its vicinity, while in the vegetative cytoplasm a weak diffuse and intense punctate signal was registered. CaM immunostain was also detected in association with the plasma membrane of the tube tips in both short and long pollen tubes. Furthermore, the cytosol of the tubes invariably manifested an apically focused CaM gradient. We were, however, unable to detect any vacuolar association of CaM in the older regions of the pollen tubes. Although punctate immunostain was obvious across the pollen tube numerous punctate structures were invariably present in the extreme tip. The possible implications of these findings in development of cell polarity, polarised growth, maintenance of calcium homeostasis and CaM interactions with other mechanochemical motor proteins in effecting propulsion of organelles during pollen hydration, germination and pollen tube growth are discussed.


Asunto(s)
Calmodulina/metabolismo , Germinación , Nicotiana/crecimiento & desarrollo , Plantas Tóxicas , Western Blotting , Calmodulina/genética , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Microscopía Confocal , Microscopía Fluorescente , Polen , Nicotiana/genética , Nicotiana/fisiología , Agua
19.
J Endocrinol Invest ; 19(9): 624-9, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8957748

RESUMEN

The pathogenesis of pseudohyperaldosteronism from licorice has been evaluated in 6 male volunteers taking daily 7 g of a commercial preparation of licorice for 7 days, corresponding to an intake of 500 mg/day of glycyrrhizic acid. Pseudohyperaldosteronism was evident during the treatment (increase of body weight, suppression of plasma renin activity and plasma aldosterone, reduction of serum potassium). The ratio (tetrahydrocortisol + allo tetrahydrocortisol)/tetrahydrocortisone in urine increased in 5 cases after 3 days of treatment, without an increase of plasma mineralocorticoid activity (PMA). In the 6th case the urinary ratio was unchanged and PMA increased from the pretreatment value. After 7 days of therapy the ratio remained high and PMA was not measurable in 3 cases, while in the other 3 cases the ratio returned to pretreatment and PMA was higher than pretreatment value. We conclude that the pseudohyperaldosteronism from licorice is initially related to decreased activity of 11 beta-hydroxysteroid-dehydrogenase and afterwards also a direct effect of licorice derivatives on mineralocorticoid receptors becomes evident in some cases. In other cases however the effect on the enzyme is prevailing probably due to individual factors.


Asunto(s)
Ácido Glicirretínico/análogos & derivados , Glycyrrhiza , Hiperaldosteronismo/inducido químicamente , Mineralocorticoides/sangre , Plantas Medicinales , 11-beta-Hidroxiesteroide Deshidrogenasas , Adulto , Aldosterona/análogos & derivados , Aldosterona/sangre , Aldosterona/orina , Ácido Glicirretínico/administración & dosificación , Ácido Glicirretínico/efectos adversos , Ácido Glicirrínico , Humanos , Hidroxiesteroide Deshidrogenasas/metabolismo , Masculino , Potasio/sangre , Renina/sangre , Tetrahidrocortisol/orina , Tetrahidrocortisona/orina
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