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1.
Int J Food Sci Nutr ; 72(2): 184-194, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32664762

RESUMEN

New neuroprotective treatments of natural origin are being investigated. Both, plant extracts and isolated compounds have shown bioactive effects. Hempseed is known for its composition of fatty acids, proteins, fibre, vitamins, as well as a large number of phytochemical compounds. After a defatting process of the seeds, hydroxycinnamic acids and its amine derivatives are the majoritarian compounds in an ethyl acetate fraction (EAF). In the present study, we investigated in vitro effect on neuronal enzymes: MAO-A, MAO-B, tyrosinase and acetylcholinesterase. Besides, the effect of EAF on striatal biogenic amines in mice was evaluated. Both, EAF and isolated compounds (N-trans-caffeoyltyramine and N-trans-coumaroyltyramine), showed inhibitory action on MAO-A, MAO-B and tyrosinase. Furthermore, an increasing of biogenic amines was observed in the corpus striatum of the mice, after administration of EAF. These findings show that EAF and the hydroxycinnamic acid derivatives may represent a potential treatment in degenerative neuronal diseases.


Asunto(s)
Sistema Nervioso Central/enzimología , Ácidos Cumáricos/farmacología , Extractos Vegetales/farmacología , Acetilcolinesterasa/metabolismo , Animales , Aminas Biogénicas , Cannabis/química , Cuerpo Estriado , Masculino , Ratones , Monoaminooxidasa/metabolismo , Monofenol Monooxigenasa/metabolismo , Fármacos Neuroprotectores/farmacología
2.
J Ethnopharmacol ; 225: 244-270, 2018 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-29933016

RESUMEN

ETHNO-PHARMACOLOGICAL RELEVANCE: Annona species (Annonaceae) have long been used as traditional herbal medicines by native peoples in tropical areas. In different countries they are used against a large variety of illnesses, such as parasitic and infectious diseases, cancer, diabetes, peptic ulcers, and mental disorders. AIM OF THE STUDY: This review aims to achieve a comprehensive understanding of the research conducted so far on the local and traditional uses, pharmacological activities, mechanism of actions of active compounds, toxicity, and possible interactions with other drugs of the Annona species. Through analysis of these findings, evidences supporting their applications in ethno-medicines are described. We discuss the possible research opportunities and stand out the weak points in our knowledge that deserves further investigation. MATERIAL AND METHODS: Information on ethno-medicinal uses and pharmacological activities of the Annona genus was collected. The main scientific biomedical literature databases (Cochrane, PubMed, Scopus, Lilacs, SeCiMed, Elsevier, SpringerLink, Google Scholar, SciFinder) were consulted. The search covered all the literature available until September 2017. National and regional databases of Herbal Medicine and Complementary and Alternative Medicine were also revised in order to explore further data. For a better understanding of the therapeutic importance of these species, we have classified the pharmacological activities within each group of disorders. The International Classification of Diseases (ICD), used from WHO Member States, was chosen as the reference classification. RESULTS: From among the 27 species revised, four species are highlighted for their important pharmacological activities in most of the groups of illnesses: A. muricata, A. squamosa, A. senegalensis, and A. cherimola. Many investigations have been performed with extracts from the leaves, bark, fruit and seeds and have shown a wide range of pharmacological activities, such as antiprotozoal, antitumoural, antidiabetic, hepato-protective, anti-inflammatory and anxiolytic activities. The chemistry on the annonaceous acetogenins (ACGs) has been extensively investigated due to their potent antitumoural activity. Many of the assays were carried out with the isolated acetogenins in different lines of tumour culture cells and were found effective at very low doses even in multidrug-resistant tumours, and hence constitute promising compounds in the treatment of different types of cancers. No studies were found with extracts rich in acetogenins in the clinical field. CONCLUSIONS: The experimental results from the pharmacological research enable the validation of their traditional uses in several of the groups of diseases in the countries of origin and reveal these plants to be a valuable source for therapeutic molecules. However, more toxicity assays and clinical trials would be necessary to establish optimal and safe doses of consumption on the application of these medicinal plants.


Asunto(s)
Annona , Fitoterapia , Animales , Etnofarmacología , Humanos , Medicina Tradicional , Preparaciones de Plantas/farmacología , Preparaciones de Plantas/uso terapéutico , Preparaciones de Plantas/toxicidad
3.
J Ethnopharmacol ; 170: 128-35, 2015 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-25975515

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Uncaria tomentosa (Willdenow ex Roemer & Schultes) DC. (Rubiaceae) is a Peruvian thorny liana, commonly known as "cat׳s claw", and traditionally used in folk medicine to deal with several inflammatory diseases. Mitraphylline (MTP) is the most abundant pentacyclic oxindolic alkaloid (POA) from U. Tomentosa and has been reported to modify the inflammatory response. Herein, we have sought to identify the mechanisms underlying this modulatory effect of MTP on primary human monocytes and its ability to regulate differentiation processes on human primary monocyte and monocyte-derived macrophages. MATERIAL AND METHODS: In vitro studies with human primary monocytes and monocyte-derived macrophages were performed. Monocytes and M0 macrophages were exposed to MTP (25µM) and LPS (100ng/mL). M0 macrophages were polarized to M1 and M2 phenotypes in the absence or presence of MTP. The activation state of monocytes/macrophages was assessed by flow cytometry, gene expression and protein analysis of different specific markers. RESULTS: In human primary monocytes, the incubation of MTP for 24h reduced the number of classical (CD14(++)CD16(-)) and intermediate (CD14(++)CD16(+)) subsets when compared to untreated or LPS-treated cells. MTP also reduced the chemotactic capacity of human primary monocytes. In addition, MTP promoted the polarization of M0 macrophages toward an anti-inflammatory M2 phenotype, the abrogation of the release of pro-inflammatory cytokines such as TNFα, IL-6 or IL-1ß, as well as the restoration of markers for M2 macrophages in LPS-treated M1 macrophages. CONCLUSIONS: Our results suggest that MTP may be a key modulator for regulating the plasticity of monocytes/macrophages and the attenuation of the inflammatory response.


Asunto(s)
Uña de Gato/química , Alcaloides Indólicos/farmacología , Macrófagos/efectos de los fármacos , Monocitos/efectos de los fármacos , Adulto , Biomarcadores/metabolismo , Diferenciación Celular/efectos de los fármacos , Quimiotaxis/efectos de los fármacos , Citocinas/metabolismo , Citometría de Flujo , Humanos , Alcaloides Indólicos/aislamiento & purificación , Inflamación/tratamiento farmacológico , Inflamación/patología , Mediadores de Inflamación/metabolismo , Lipopolisacáridos/toxicidad , Macrófagos/citología , Monocitos/citología , Oxindoles
4.
J Viral Hepat ; 22(3): 297-306, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25164560

RESUMEN

Transient elastography (TE) is the reference method to obtain liver stiffness measurements (LSM), but no results are obtained in 3.1% and unreliable in 15.8%. We assessed the applicability and diagnostic accuracy of TE re-evaluation using M and XL probes. From March 2011 to April 2012 868 LSM were performed with the M probe by trained operators (50-500 studies) (LSM1). Measurements were categorized as inadequate (no values or ratio <60% and/or IQR/LSM >30%) or adequate. Inadequate LSM1 were re-evaluated by experienced operators (>500 explorations) (LSM2) and inadequate LSM2 using XL probe (LSMXL). Inadequate LSM1 were obtained in 187 (21.5%) patients, IQR/LSM >30% in 97 (51%), ratio <60% in 24 (13%) and TE failed to obtain a measurement in 67 (36%). LSM2 achieved adequate registers in 123 (70%) of 175 registers previously considered as inadequate. Independent variables (OR, 95%CI) related to inadequate LSM1 were body mass index (1.11, 1.04-1.18), abdominal circumference (1.03, 1.01-1.06) and age (1.03, 1.01-1.04) and to inadequate LSM2 were skin-capsule distance (1.21, 1.09-1.34) and abdominal circumference (1.05, 1.01-1.10). The diagnostic accuracy (AUROC) to identify significant fibrosis improved from 0.89 (LSM1) to 0.91 (LSM2) (P = 0.046) in 334 patients with liver biopsy or clinically significant portal hypertension. A third evaluation (LSMXL) obtained adequate registers in 41 (93%) of 44 patients with inadequate LSM2. Operator experience increases the applicability and diagnostic accuracy of TE. The XL probe may be recommended for patients with inadequate values obtained by experienced operators using the M probe. http://clinicaltrials.gov (NCT01900808).


Asunto(s)
Diagnóstico por Imagen de Elasticidad/métodos , Diagnóstico por Imagen de Elasticidad/normas , Hígado/diagnóstico por imagen , Hígado/patología , Competencia Profesional , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Femenino , Humanos , Hepatopatías/diagnóstico por imagen , Hepatopatías/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Curva ROC , Reproducibilidad de los Resultados , Factores de Riesgo , Adulto Joven
5.
J Agric Food Chem ; 62(5): 1105-10, 2014 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-24422510

RESUMEN

Non-drug varieties of Cannabis sativa L., collectively namely as "hemp", have been an interesting source of food, fiber, and medicine for thousands of years. The ever-increasing demand for vegetables oils has made it essential to characterize additional vegetable oil through innovative uses of its components. The lipid profile showed that linoleic (55%), α-linolenic (16%), and oleic (11%) were the most abundant fatty acids. A yield (1.84-1.92%) of unsaponifiable matter was obtained, and the most interesting compounds were ß-sitosterol (1905.00 ± 59.27 mg/kg of oil), campesterol (505.69 ± 32.04 mg/kg of oil), phytol (167.59 ± 1.81 mg/kg of oil), cycloartenol (90.55 ± 3.44 mg/kg of oil), and γ-tocopherol (73.38 ± 2.86 mg/100 g of oil). This study is an interesting contribution for C. sativa L. consideration as a source of bioactive compounds contributing to novel research applications for hemp seed oil in the pharmaceutical, cosmetic food, and other non-food industries.


Asunto(s)
Cannabis/química , Aceites de Plantas/química , Semillas/química , Fitosteroles/análisis , Sitoesteroles/análisis , Tocoferoles/análisis , Triterpenos/análisis
6.
J Ethnopharmacol ; 151(1): 131-6, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24239848

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Evening primrose (Oenothera biennis L., Onagraceae) is a wild medicinal plant of Central American origin that is now one of the most widely used herbal medicines in different parts of the world. Oil extracted from it seeds is traditionally used in the treatment of eczema, asthma, rheumatoid arthritis, breast problem, premenstrual and menopausal syndrome, all they have an inflammatory component. The present study demonstrates the in vitro anti-inflammatory effect of long-chain fatty alcohols, minor compounds isolated from Evening primrose oil (EPO). MATERIAL AND METHODS: A mixture of long chain fatty alcohols (LCFAs) was isolated from the non-triacylglycerol fraction of the EPO. Hexacosanol (C26OH: 38.65%), tetracosanol (C24OH: 31.59%), docosanol (C22OH: 11.36%) and octocosanol (C28OH: 7.64%), were the major constituents, identified and quantified by GC and GC-MS. LCFA was tested with LPS stimulated murine peritoneal macrophage. This fraction, significantly and dose-dependently decreased nitric oxide production induced by LPS (P<0.001) and the inhibitory effect seems to be consequence of an action at the level of the inducible nitric-oxide synthethase (iNOS) gene enzyme expression rather than to a direct inhibitory action on enzyme activity. The release of PLA2 and TXB2 also was significantly inhibited by LCFAs (P<0.001) although LCFAs did not affect to PGE2 generation, however the western blot assay showed that LCFAs reduced cyclooxygenase-2 enzyme gene expression at all doses assayed. In the same way, the secretion of inflammatory cytokines interleukin 1ß (IL-1ß) and tumour necrosis factor α (TNF-α) from LPS-stimulated murine macrophage, were also significantly reduced (P<0.001). CONCLUSION: These results demonstrates the anti-inflammatory activity of LCFAs, providing an additional value about the role of bioactive minor compounds in the beneficial effect of EPO and supports its traditional uses in inflammatory processes management.


Asunto(s)
Alcoholes Grasos/química , Alcoholes Grasos/farmacología , Inflamación/metabolismo , Ácidos Linoleicos/química , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/metabolismo , Aceites de Plantas/química , Ácido gammalinolénico/química , Animales , Supervivencia Celular , Dinoprostona/genética , Dinoprostona/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Ratones , Nitritos/metabolismo , Oenothera biennis , Fosfolipasas A2 Secretoras/genética , Fosfolipasas A2 Secretoras/metabolismo , Tromboxano B2/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
7.
Cytogenet Genome Res ; 134(3): 191-9, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21540576

RESUMEN

Here we provide the first detailed description of the hybrid zone between the Cremona chromosomal race of house mouse (ICRE; 2n = 22) and the standard all-telocentric race (40ST; 2n = 40), with full karyotypes of 106 individuals from 17 localities along a transect between the 2 races to the west of Lake Garda in Northern Italy. The ICRE race is characterised by 9 pairs of metacentric chromosomes in a homozygous state and we use the metacentric frequency data along the transect to fit tanh metacentric clines. The clines are narrow (5-8 km, standardised width) suggesting low hybrid fitness. However, the lack of occurrence of ICRE × 40ST F(1) hybrids and presence of other hybrid types suggests that the F(1) hybrids initially produced in this hybrid zone were at least partially fertile, despite having 9 meiotic trivalent configurations. We apply the same cline-fitting methodology to 3 previously studied hybrid zones between metacentric races and the 40ST race. Taken together with published clinal data on 4 further metacentric-40ST hybrid zones, we are able to make objective generalisations on the characteristics of such zones in the house mouse. Zones involving 22-chromosome races are narrower, on average, than other metacentric-40ST hybrid zones and do not show a tendency towards the generation of new races as found with zones where the metacentric race has a higher 2n. It appears that metacentric-40ST zones are unlikely to be sites of speciation (even when a 22-chromosome race is involved), although a mosaic structure to the hybrid zone may enhance this possibility. We make a comparison between metacentric-40ST zones and contacts between 2 metacentric races, for a comprehensive perspective of chromosomal hybrid zones in the house mouse.


Asunto(s)
Hibridación Genética , Ratones/genética , Animales , Italia , Cariotipificación
8.
Pharmazie ; 62(6): 459-62, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17663195

RESUMEN

Helichrysum picardii Boiss. & Reuter is a Mediterranean vegetal species from the Asteraceae family. From the methanolic extract of the aerial flowering parts of this plant, a fraction of two pentacyclic triterpenes has been isolated. Gas chromatography revealed that the triterpene isomers ursolic and oleanolic acids comprised 69% and 29% respectively of the composition of this fraction. The triterpene isomeric fraction was tested in two phagocyte cell systems. It inhibited compound 48/80-induced histamine release from rat peritoneal mast cells in an approximately percentage of 45% at 100 microM and myeloperoxidase secretion from A23187-ionophore-stimulated rat peritoneal leukocytes in a significant manner at doses of 50 and 100 miroM. Furthermore, the triterpene isomers very significantly and dose-dependently inhibited generation of the cyclo-oxygenase metabolite prostaglandin E2 (41% inhibition at 50 miroM) and the 5-lipoxygenase metabolite leukotriene B4 (79% inhibition at 50 microM) from activated rat leukocytes. This anti-eicosanoid activity of the triterpene fraction was more potent than that produced by the pure triterpene oleanolic acid used for comparision, indicating a stronger action of the ursolic acid, the major compound of the isolated triterpene fraction. From these data, it can be suggested that the triterpene isomers oleanolic and ursolic acids present in the medicinal plant Helichrysum picardii contribute to the anti-inflammatory profile of this vegetal species.


Asunto(s)
Eicosanoides/antagonistas & inhibidores , Helichrysum/química , Antagonistas de los Receptores Histamínicos/farmacología , Ácido Oleanólico/farmacología , Triterpenos/farmacología , Animales , Calcimicina/farmacología , Cromatografía en Capa Delgada , Gránulos Citoplasmáticos/efectos de los fármacos , Gránulos Citoplasmáticos/enzimología , Flores/química , Cromatografía de Gases y Espectrometría de Masas , Liberación de Histamina/efectos de los fármacos , Técnicas In Vitro , Indicadores y Reactivos , Ionóforos/farmacología , Isomerismo , Leucocitos/efectos de los fármacos , Leucocitos/enzimología , Leucocitos/metabolismo , Masculino , Mastocitos/efectos de los fármacos , Mastocitos/metabolismo , Metanol , Peroxidasa/metabolismo , Ratas , Ratas Wistar , Solventes , p-Metoxi-N-metilfenetilamina/farmacología , Ácido Ursólico
9.
Phytomedicine ; 14(4): 280-4, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17296291

RESUMEN

Uncaria tomentosa inner bark extract is a popular plant remedy used in folk medicine to treat tumor and inflammatory processes. In this study, the anti-tumoral effects of its pentacyclic alkaloid mitraphylline were investigated. Furthermore, its growth-inhibitory and cytotoxic effects on glioma GAMG and neuroblastoma SKN-BE(2) cell lines were studied using cyclophosphamide and vincristine as controls. A colter counter was used to determine viable cell numbers, followed by application of the tetrazolium compound [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)2-(4-sulfophenyl)-2H-tetrazolium], inner salt, colorimetric method to evaluate cell viability in this cytotoxicity assay. Micromolar concentrations of mitraphylline (from 5 to 40 microM) inhibited the growth of both cell lines. It inhibited the growth of the two cell lines studied in a dose-dependent manner. The IC(50) values were 12.3 microM (30h) for SKN-BE(2) and 20 microM (48 h) for GAMG, respectively. This action suggests that mitraphylline is a new and promising agent in the treatment of human neuroblastoma and glioma.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Uña de Gato , Supervivencia Celular/efectos de los fármacos , Alcaloides Indólicos/farmacología , Fitoterapia , Extractos Vegetales/farmacología , Alcaloides/administración & dosificación , Alcaloides/farmacología , Alcaloides/uso terapéutico , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/uso terapéutico , Línea Celular Tumoral/efectos de los fármacos , Glioma/tratamiento farmacológico , Humanos , Alcaloides Indólicos/administración & dosificación , Alcaloides Indólicos/uso terapéutico , Indoles/administración & dosificación , Indoles/farmacología , Indoles/uso terapéutico , Concentración 50 Inhibidora , Neuroblastoma/tratamiento farmacológico , Oxindoles , Corteza de la Planta , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico
10.
J Viral Hepat ; 12(5): 481-7, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16108762

RESUMEN

SUMMARY: Early virological response may predict outcome following treatment with peginterferon alpha-2a and ribavirin in patients chronically infected with hepatitis C virus (HCV). As total HCV core antigen may constitute an alternative direct marker to HCV RNA for assessing the levels of viraemia in such patients, we evaluated the correlation between HCV core antigen and HCV RNA, and whether HCV core antigen at baseline, 4 and 12 weeks after treatment could predict sustained virological response (SVR) to combined therapy, in comparison with HCV RNA. A total of 290 serum samples from 58 previously treatment naïve chronic HCV patients were examined for HCV core antigen and HCV-RNA by means of quantitative HCV RNA when receiving combination therapy for the first time. SVR was significantly associated with basal HCV core antigen but not with HCV RNA. There was a good correlation between HCV core antigen and HCV RNA (r(2) = 0.781). The negative predictive value of HCV core antigen testing in predicting nonresponse at weeks 4 and 12 were 75 and 100%, and for undetectable or a 2-log drop in HCV RNA were 69.6 and 75% respectively. HCV core antigen detection is quick, and easy to perform alternative to HCV RNA, and could be used as a marker of HCV viraemia for monitoring the progress of therapy.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/metabolismo , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Quimioterapia Combinada , Hepacivirus/genética , Hepacivirus/inmunología , Hepatitis C Crónica/sangre , Hepatitis C Crónica/virología , Humanos , Interferón alfa-2 , ARN Viral/sangre , Proteínas Recombinantes , Resultado del Tratamiento , Proteínas del Núcleo Viral/análisis , Proteínas del Núcleo Viral/sangre , Proteínas del Núcleo Viral/efectos de los fármacos , Viremia/tratamiento farmacológico , Viremia/virología
11.
Scand J Rheumatol ; 33(5): 323-6, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15513681

RESUMEN

OBJECTIVE: To evaluate the clinical response and safety profile of infliximab in refractory ankylosing spondylitis patients. METHODS: Patients with active ankylosing spondylitis, despite methotrexate therapy, were included in an open-label, single-centre study. Patients were given 3-5 mg/kg infliximab infusions at Weeks 0, 2, 6, and q8 etc up to Week 30, together with methotrexate at the dosage taken prior to study inclusion, and were followed-up for a 34-week period. RESULTS: Nine patients with mean age 43 years and mean disease duration 7 years, diagnosed with pure axial ankylosing spondylitis were included. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), duration of morning stiffness, physician's global assessment of disease activity (PhGADA), visual analogue scale (VAS) pain, enthesis index, occiput-to-wall test, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Functional Index (BASFI) significantly improved by Week 6. No adverse events related with the drug were recorded during the 34-week follow-up period. CONCLUSION: Efficacy results are similar to those previously published. No adverse events were seen during therapy, and antinuclear antibody profiles were negative. The association of methotrexate with infliximab can improve the safety profile.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antirreumáticos/uso terapéutico , Espondilitis Anquilosante/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/administración & dosificación , Antirreumáticos/administración & dosificación , Sedimentación Sanguínea , Proteína C-Reactiva/análisis , Esquema de Medicación , Femenino , Humanos , Inflamación , Infliximab , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Espondilitis Anquilosante/fisiopatología
12.
Genome ; 45(6): 1110-5, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12502256

RESUMEN

Synaptic behaviour and the progression of morphological differentiation of the XY chromosome pair during pachytene was studied for the first time in three species of the South American subterranean rodents of the genus Ctenomys (tuco-tucos). In general, synapsis progression in the sex pair could be subdivided into four substages: (i) initial partial synapsis of the X and Y chromosome axes and beginning of the differentiation of the unsynapsed regions; (ii) complete or almost complete synapsis of the Y axis accompanied with morphological differentiation of the unsynapsed region of the X chromosome; (iii) a novel stage exclusive to Ctenomys perrensi consisting in a retraction of the free X axis, associated with the formation of a homogeneous and dense structure along the synaptic region, which leads to the achievement of full synapsis between sex chromosomes; or (iv) an increase in morphological complexity involving extreme splitting of the XY pair. The implications of the peculiar synaptic behaviour displayed by sex chromosomes in C. perrensi, a species complex highly polymorphic for Robertsonian translocations, are discussed in relation to both the triggering of the pachytene checkpoint and the avoidance of non-homologous associations between sex chromosomes and the asynaptic pericentromeric regions of trivalents in translocation heterozygotes.


Asunto(s)
Emparejamiento Cromosómico , Roedores/genética , Cromosoma X , Cromosoma Y , Animales , Masculino , Meiosis , Roedores/clasificación , Especificidad de la Especie
13.
Cytogenet Genome Res ; 96(1-4): 130-6, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12438789

RESUMEN

The tuco-tucos (Ctenomys) are South American subterranean rodents that are some of the most chromosomally variable of all mammals. In this study we focus on Ctenomys of the "Corrientes species group" from that Argentine province and consisting of C. dorbignyi, C. perrensi, C. roigi and unnamed populations (Ctenomys sp.). A diploid range of 41-70 has been demonstrated for these taxa with multiple Robertsonian changes, pericentric inversions, heterochromatic modifications and other chromosomal rearrangements. To analyse the molecular variation in the Corrientes group, a 402 base pair fragment of mitochondrial cytochrome b was sequenced in 75 individuals from 26 populations. This generated 15 different haplotypes which were subjected to phylogenetic analysis. The different species within the Corrientes group failed to form monophyletic groups in the phylogenetic trees we generated and the divergences between haplotypes were low. Therefore, these molecular data demonstrate the recent subdivision of the Corrientes group with a substantial accumulation of chromosomal differences. Through our new chromosomal data and cytochrome b studies, we are able to subdivide the Ctenomys sp. populations into two groups and hypothesize on their relationships with the described Corrientes group species. Further studies are needed to establish the basis of the phenomenal chromosomal variation in this group.


Asunto(s)
Mapeo Cromosómico , Cariotipificación , Roedores/genética , Animales , Argentina , Secuencia de Bases , Grupo Citocromo b/química , Grupo Citocromo b/genética , Diploidia , Variación Genética , Geografía , Filogenia , Roedores/clasificación , Alineación de Secuencia , Homología de Secuencia de Ácido Nucleico
14.
Heredity (Edinb) ; 87(Pt 3): 305-13, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11737277

RESUMEN

Chiasma frequency and distribution were studied in male Mus musculus domesticus from the John O'Groats-standard chromosomal hybrid zone in northern Scotland. Individuals of the John O'Groats race (2n=32; homozygous for the Robertsonian fusions 4.10, 6.13, 9.12 and 11.14) and the standard race (2n=40, all telocentric), and hybrids with various karyotypes, were examined. Chiasma frequency was significantly negatively correlated with the number of Robertsonian configurations in the meiotic cell. The decrease of chiasma frequency can be attributed to intrachromosomal effects that reduce the number of chiasmata in Robertsonian bivalents (formed in homozygotes for Robertsonian fusions) and trivalents (formed in heterozygotes). However, the reduction is more pronounced in Robertsonian bivalents and is related to a shift of chiasmata to the distal ends of the chromosome arms. A different type of repatterning occurs in trivalents where there is a significant increase in proximal and interstitial chiasmata.


Asunto(s)
Cromosomas/genética , Ratones/genética , Animales , Quimera , Intercambio Genético , Genética de Población , Heterocigoto , Homocigoto , Hibridación Genética , Cariotipificación , Masculino , Meiosis/genética , Especificidad de la Especie
15.
Z Naturforsch C J Biosci ; 54(7-8): 605-9, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10488570

RESUMEN

Antimicrobial activity in some lichens from south Spain has been studied. Some lichenical substances are also identified. The structures of all compounds were elucidated by physical, spectral and chemical methods. A very high activity against Gram-positive bacteria has been observed in lichens containing usnic acid.


Asunto(s)
Antibacterianos/aislamiento & purificación , Líquenes/química , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana
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