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1.
Chaos ; 33(1): 013126, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36725622

RESUMEN

We analyze the nonlinear dynamics of a quartic semiclassical system able to describe the interaction of matter with a field. We do it in both dissipative and conservative scenarios. In particular, we study the classical limit of both frameworks and compare the associated features. In the two environments, we heavily use a system's invariant, related to the Uncertainty Principle, that helps to determine how the dynamics tends to the pertinent classical limit. We exhibit the convergence to the classical limit and also verify that the Uncertainty Principle is complied with during the entire process, even in the presence of dissipation.

2.
Br Poult Sci ; 62(2): 166-171, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33325274

RESUMEN

1. This study was undertaken to evaluate genetic diversity among three varieties of Japanese quail (British Range, English White and Tuxedo) differing in plumage colour. The level of genetic variation was rated through the histone H1 polymorphic loci (H1.b and H1.z) containing quantitatively similar (P > 0.05) isoforms (H1.b1, H1.b2 and H1.z1, H1.z2) that form both homozygous (b1, b2 and z1, z2) and heterozygous (b1b2 and z1z2) phenotypes.2. The complete set of histone H1 phenotypes were characteristic of the British Range and Tuxedo varieties. Phenotypes b2 and z2 were not detected in the English White variety. A lack of the former phenotypes resulted in excess of heterozygotes at loci H1.b (F = -0.563) and H1.z (F = -0.562), pointing to the presence of outbreeding.3. The English White variety deviated from Hardy-Weinberg proportions (H1.b - Χ2 = 7.61, P < 0.05 and H1.z - Χ2 = 5.84, P < 0.05), in contrast to the British Range variety (H1.b - Χ2 = 0.86, P > 0.05 and H1.z - Χ2 = 0.86, P > 0.05) and Tuxedo (H1.b - Χ2 = 1.6, P > 0.05 and H1.z - Χ2 = 1.6, P > 0.05). The estimated values of the FST index for loci H1.b (0.073) and H1.z (0.099) indicate a moderate genetic diversity of the quail population.4. The distinct array and distribution of histone H1 phenotypes among quail varieties suggested that histone H1 allelic variants might have an individual impact on characteristic pigmentation of poultry.


Asunto(s)
Histonas , Codorniz , Animales , Pollos , Coturnix/genética , Electroforesis en Gel de Poliacrilamida/veterinaria , Eritrocitos , Histonas/genética , Polimorfismo Genético
3.
Theor Appl Genet ; 126(7): 1793-808, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23558983

RESUMEN

Hexaploid bread wheat evolved from a rare hybridisation, which resulted in a loss of genetic diversity in the wheat D-genome with respect to the ancestral donor, Aegilops tauschii. Novel genetic variation can be introduced into modern wheat by recreating the above hybridisation; however, the information associated with the Ae. tauschii accessions in germplasm collections is limited, making rational selection of accessions into a re-synthesis programme difficult. We describe methodologies to identify novel diversity from Ae. tauschii accessions that combines Bayesian analysis of genotypic data, sub-species diversity and geographic information that summarises variation in climate and habitat at the collection point for each accession. Comparisons were made between diversity discovered amongst a panel of Ae. tauschii accessions, bread wheat varieties and lines from the CIMMYT synthetic hexaploid wheat programme. The selection of Ae. tauschii accessions based on differing approaches had significant effect on diversity within each set. Our results suggest that a strategy that combines several criteria will be most effective in maximising the sampled variation across multiple parameters. The analysis of multiple layers of variation in ex situ Ae. tauschii collections allows for an informed and rational approach to the inclusion of wild relatives into crop breeding programmes.


Asunto(s)
Variación Genética , Triticum/genética , Teorema de Bayes , Clima , Ambiente , Genotipo , Hibridación Genética , Fenotipo , Poaceae/genética
4.
Drugs Today (Barc) ; 56(12): 755-768, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33332482

RESUMEN

Fedratinib hydrochloride is a selective Janus kinase 2 (JAK2) inhibitor approved by the U.S. Food and Drug Administration (FDA) in August 2019 for intermediate- 2 or high-risk primary or secondary myelofibrosis. The approval of this novel oral agent was based on the phase II and III JAKARTA-2 and JAKARTA trials, which both showed significant reduction in splenomegaly and myelofibrosis symptom burden. The most common adverse effects associated with fedratinib include anemia, gastrointestinal symptoms and elevation in liver transaminases. Early clinical trial data was concerning for an increased incidence of Wernicke's encephalopathy (WE), which led the FDA to place a clinical hold on further drug development. However, upon further investigation it was determined that there was no clear evidence that fedratinib causes WE, and the clinical hold was lifted in 2017. This inclusive review provides insight into the pharmacology, safety and efficacy, and future direction of fedratinib use in myeloproliferative neoplasms.


Asunto(s)
Mielofibrosis Primaria , Desarrollo de Medicamentos , Humanos , Mielofibrosis Primaria/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/efectos adversos , Pirrolidinas , Sulfonamidas
5.
Med Vet Entomol ; 23 Suppl 1: 106-10, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19335837

RESUMEN

The geographical distribution and seasonality of the New World screwworm (NWS), Cochliomyia hominivorax Coquerel (Diptera: Calliphoridae), were monitored through the use of sentinel animals as part of a co-ordinated programme involving veterinarians and farmers, as well as undergraduate students and teachers from veterinary colleges in Venezuela. This surveillance activity made it possible to collect NWS egg masses or larvae from all 23 states in the country and to determine that the rainy season has a strong positive influence on the number of cases of myiasis caused by C. hominivorax in dogs. In addition, efforts were made to obtain the co-operation of the public health service in order to document the extent of human myiasis in the western-central region of Venezuela. Preliminary results revealed 241 cases over a 7-year period, with cases reported in infants as well as in elderly people. Larvae causing myiasis, other than C. hominivorax, were collected from primary myiasis in rabbit (Lucilia eximia [Wiedemann]), dog (an unidentified sarcophagid species), birds (Philornis sp.) and wild mice (Cuterebra sp.). The economic impact of NWS in Venezuela has not been calculated in terms of loss of milk and meat production, damage to hides or death of animals. Control costs (e.g. cost of larvicides) have been estimated at US$ 2 m per year. Control of myiasis in animals is achieved through the use of chemical compounds, mainly organophosphorus (OP) compounds, macrocyclic lactones and, more recently, a foamy spray based on spinosad. Concerns about insecticide resistance to OP compounds have been raised.


Asunto(s)
Dípteros/patogenicidad , Infección por Gusano Barrenador/veterinaria , Anciano , Animales , Animales Domésticos/parasitología , Costos y Análisis de Costo , Geografía , Humanos , Lactante , Insecticidas/economía , Insecticidas/farmacología , Carne/parasitología , Leche/parasitología , Miasis/economía , Miasis/prevención & control , Miasis/veterinaria , Infección por Gusano Barrenador/economía , Infección por Gusano Barrenador/epidemiología , Venezuela/epidemiología
6.
Pol J Vet Sci ; 12(2): 231-5, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19645354

RESUMEN

The results of studies conducted in 2006 revealed that mass red mite (Dermanyssus gallinae) invasions cause somatic stress which may be responsible for the pathophysiological mechanism of decreased egg production, lower humoral immunity and higher mortality in layer hens. The aim of this study was to validate the above research results, to investigate whether in addition to somatic stress, red mite invasions cause psychogenic stress due to the activation of the sympatho-adrenomedullar system, and to determine the level of stress resulting from red mite infestations in comparison with a short, 1.5 h period of acute immobilisation stress. The study investigated 36 HY-Line Brown layer hens divided into three groups: a non-infested control group, an experimental group infested with red mites and a non-infested experimental group subjected to acute immobilisation stress for 1.5 h. Blood samples were taken from all hens for the determination of the levels of corticosterone, adrenaline, noradrenaline, albumin, and alpha-, beta- and gamma-globulins. The results validated the previous reports on the occurrence of somatic stress and on a significant decrease in y-globulin levels (p < or = 0.01) in the group of birds infested with red mites, in comparison with the control group. Adrenaline levels in infested hens were indicative of psychogenic stress. Based on a comparison of hormonal indicators in all hen groups, the level of somatic stress resulting from red mite infestation can be classified as moderate, while the level of psychogenic stress can be interpreted as high. A significant drop in y-globulin levels in the blood of birds infested with red mites also shows that the invasion induces chronic stress which lowers the humoral immunity of hens.


Asunto(s)
Proteínas Sanguíneas/metabolismo , Catecolaminas/sangre , Pollos , Corticosterona/sangre , Infestaciones por Ácaros/veterinaria , Enfermedades de las Aves de Corral/parasitología , Animales , Femenino , Infestaciones por Ácaros/sangre , Ácaros/clasificación , Oviposición , Enfermedades de las Aves de Corral/sangre , Restricción Física , Estrés Fisiológico
7.
Transplant Proc ; 50(7): 2140-2144, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30177126

RESUMEN

Combined liver-kidney transplantation (CLKT) is a rare procedure in pediatric patients in which liver and kidney from 1 donor are transplanted to a recipient during a single operation. The aim of our study was to analyze indications and results of CLKT in children. MATERIALS AND METHODS: Between 1990 and 2017 we performed 722 liver transplantations in children; we performed 920 kidney transplantations in children since 1984. Among them, 25 received CLKT. Primary diagnosis was fibro-polycystic liver and kidney disease in 17 patients, primary hyperoxaluria type 1 in 6 patients, and atypical hemolytic uremic syndrome-related renal failure in 2 children. Age of patients at CLKT was 3 to 23 years (median 16 years) and body mass was 11 to 55 kg (median 35.5kg). All patients received whole liver graft. Kidney graft was transplanted after liver reperfusion before biliary anastomosis. Cold ischemia time was 5.5 to 13.3 hours (median 9.4 hours) for liver transplants and 7.3 to 15 hours (median 10.4 hours) for kidney transplants. In 8 patients X-match was positive. We analyzed posttransplant (Tx) course and late results in our group of pediatric recipients of combined grafts. RESULTS: Tx follow-up ranged from 1.5 to 17 years (median 4.5 years). Two patients died: 1 patient with oxalosis lost renal graft and died 2.6 years after Tx due to complications of long-term dialysis, and 1 died due to massive bleeding in early postoperative period. Twelve patients were transferred under the care of adult transplantation centers. Six patients were dialyzed after CLKT due to acute tubular necrosis, and time of kidney function recovery was 10 to 27 days in these patients. In 1 patient with aHUS, renal function did not recover. In children with oxalosis, hemodialysis was performed for 1 month after Tx as a standard, with the aim to remove accumulated oxalate. Primary immunosuppression consisted of daclizumab or basiliximab, tacrolimus, mycophenolate mofetil, and steroids. Acute rejection occurred in 4 liver and 3 kidney grafts. One patient required liver retransplantation due to hepatitis C virus recurrence and 2 patients required kidney retransplantation. Two patients required dialysis. CONCLUSIONS: CLKT in children results in low rate of rejection and high rate of patient and graft survival.


Asunto(s)
Trasplante de Riñón/métodos , Trasplante de Hígado/métodos , Adolescente , Niño , Preescolar , Femenino , Supervivencia de Injerto , Humanos , Masculino , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
8.
Environ Pollut ; 149(1): 31-43, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17337104

RESUMEN

Concentrations of nitrogen gases (NH(3), NO(2), NO, HONO and HNO(3)) and particles (pNH(4) and pNO(3)) were measured over a mixed coniferous forest impacted by high nitrogen loads. Nitrogen dioxide (NO(2)) represented the main nitrogen form, followed by nitric oxide (NO) and ammonia (NH(3)). A combination of gradient method (NH(3) and NO(x)) and resistance modelling techniques (HNO(3), HONO, pNH(4) and pNO(3)) was used to calculate dry deposition of nitrogen compounds. Net flux of NH(3) amounted to -64 ng N m(-2) s(-1) over the measuring period. Net fluxes of NO(x) were upward (8.5 ng N m(-2) s(-1)) with highest emission in the morning. Fluxes of other gases or aerosols substantially contributed to dry deposition. Total nitrogen deposition was estimated at -48 kg N ha(-1) yr(-1) and consisted for almost 80% of NH(x). Comparison of throughfall nitrogen with total deposition suggested substantial uptake of reduced N (+/-15 kg N ha(-1) yr(-1)) within the canopy.


Asunto(s)
Contaminantes Atmosféricos/análisis , Agricultura Forestal , Nitrógeno/análisis , Pinus sylvestris , Lluvia Ácida , Aerosoles , Amoníaco/análisis , Monitoreo del Ambiente/métodos , Modelos Teóricos , Países Bajos , Nitratos/análisis , Ácido Nítrico/análisis , Óxido Nítrico/análisis , Dióxido de Nitrógeno/análisis , Ácido Nitroso/análisis , Oxidación-Reducción , Material Particulado
9.
Environ Sci Pollut Res Int ; 24(1): 547-557, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27734315

RESUMEN

The study was carried out to determine the content of mercury in bone tissue of the proximal femur (head and neck bone) of 95 patients undergoing total hip replacement due to osteoarthritis, using CF-AFS analytical technique. Furthermore, the investigations were aimed at assessing the impact of selected factors, such as age, gender, tobacco smoking, alcohol consumption, exposure to chemical substance at work, type of degenerative changes, clinical evaluation and radiological parameters, type of medications, on the concentration of mercury in the head and neck of the femur, resected in situ. Mercury was obtained in all samples of the head and neck of the femur (n = 190) in patients aged 25-91 years. The mean content of mercury for the whole group of patients was as follows: 37.1 ± 35.0 ng/g for the femoral neck and 24.2 ± 19.5 ng/g for the femoral head. The highest Hg contents were found in femoral neck samples, both in women and men, and they amounted to 169.6 and 176.5 ng/g, respectively. The research showed that the mercury content of bones can be associated with body mass index, differences in body anatomy, and gender. The uses of statistical analysis gave the possibility to define the influence of factors on mercury content in human femoral bones.


Asunto(s)
Cabeza Femoral/química , Cuello Femoral/química , Articulación de la Cadera/química , Mercurio/análisis , Adulto , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Persona de Mediana Edad
10.
Contemp Clin Trials ; 60: 113-124, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28642211

RESUMEN

INTRODUCTION: Depression and diabetes are highly prevalent worldwide and often co-exist, worsening outcomes for each condition. Barriers to diagnosis and treatment are exacerbated in low and middle-income countries with limited health infrastructure and access to mental health treatment. The INtegrating DEPrEssioN and Diabetes treatmENT (INDEPENDENT) study tests the sustained effectiveness and cost-effectiveness of a multi-component care model for individuals with poorly-controlled diabetes and depression in diabetes clinics in India. MATERIALS AND METHODS: Adults with diabetes, depressive symptoms (Patient Health Questionnaire-9 score≥10), and ≥1 poorly-controlled cardiometabolic indicator (either HbA1c≥8.0%, SBP≥140mmHg, and/or LDL≥130mg/dl) were enrolled and randomized to the intervention or usual care. The intervention combined collaborative care, decision-support, and population health management. The primary outcome is the between-arm difference in the proportion of participants achieving combined depression response (≥50% reduction in Symptom Checklist score from baseline) AND one or more of: ≥0.5% reduction in HbA1c, ≥5mmHg reduction in SBP, or ≥10mg/dl reduction in LDL-c at 24months (12-month intervention; 12-month observational follow-up). Other outcomes include control of individual parameters, patient-centered measures (i.e. treatment satisfaction), and cost-effectiveness. RESULTS: The study trained seven care coordinators. Participant recruitment is complete - 940 adults were screened, with 483 eligible, and 404 randomized (196 to intervention; 208 to usual care). Randomization was balanced across clinic sites. CONCLUSIONS: The INDEPENDENT model aims to increase access to mental health care and improve depression and cardiometabolic disease outcomes among complex patients with diabetes by leveraging the care provided in diabetes clinics in India (clinicaltrials.gov number: NCT02022111).


Asunto(s)
Manejo de Caso/organización & administración , Depresión/epidemiología , Depresión/terapia , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/terapia , Autocuidado/métodos , Adulto , Anciano , Presión Sanguínea , Manejo de Caso/economía , LDL-Colesterol/sangre , Análisis Costo-Beneficio , Femenino , Hemoglobina Glucada , Humanos , India , Masculino , Persona de Mediana Edad , Entrevista Motivacional/métodos , Educación del Paciente como Asunto/métodos , Proyectos de Investigación , Método Simple Ciego
11.
Transplant Proc ; 38(1): 253-4, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16504717

RESUMEN

Treatment of patients with fulminant liver failure is a challenge of contemporary medicine. Liver transplantation, in this group, is presently the only reasonable alternative, but in many patients the disastrous condition of the patient results in serious life-threatening complications, including neurological sequelae, which may influence the quality of life after transplantation, and in some cases even cause death. From 1990 to 2004, we performed 241 liver transplantations in children, including 20 transplanted due to fulminant liver failure (8.2%). Serious neurological complications followed liver transplantation in five cases (20%), three of which were fatal. The analysis revealed that the duration of pretransplant coma (grade III or IV) strongly correlated with the incidence of neurological complications (P < .05). Also a suboptimal quality of the donor liver and poor early graft function may contribute to these posttransplant complications.


Asunto(s)
Fallo Hepático Agudo/cirugía , Trasplante de Hígado , Enfermedades del Sistema Nervioso/etiología , Complicaciones Posoperatorias/clasificación , Adolescente , Adulto , Niño , Preescolar , Coma/epidemiología , Coma/etiología , Humanos , Hepatopatías/clasificación , Hepatopatías/cirugía , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/mortalidad , Estudios Retrospectivos , Análisis de Supervivencia
12.
Cancer Res ; 48(5): 1233-7, 1988 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-2963688

RESUMEN

Two types of receptors for insulin-like growth factors (IGFs) were characterized in glioma cell lines established from different human brain tumors of glial origin (astrocytoma grades III and IV) by competitive binding assay, affinity labeling, and protein phosphorylation. Type I IGF receptor is a heterodimer composed of alpha-subunits (Mr 130,000), which bind IGF I and II with equal affinity, and of beta-subunits (Mr 98,000), which show tyrosine kinase activity and autophosphorylation stimulated by IGF I and II with equal potency. The type II IGF binding site is a monomer (Mr 250,000) which binds IGF II with 10 times higher affinity than IGF I. The cellular concentration of type II IGF binding site is about 2- to 5-fold higher than the amount of type I IGF receptor. The characteristics of the two types of IGF receptors in human glioma cell lines are similar to those described recently in fetal rat astrocytes. In contrast the type I IGF receptor in glioma cells is different from that studied previously in normal adult brain regarding the equal affinity for IGF I and II, and the higher molecular size of the alpha-subunit (130,000 versus 115,000). It is suggested that glioma cells may represent a fetal cell type in tumor development of adult human brain. A role of IGF in malignant glioma has not yet been determined, but the presence of IGF receptors is a prerequisite for cellular actions of IGF.


Asunto(s)
Neoplasias Encefálicas/análisis , Glioma/análisis , Factor II del Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Receptor de Insulina/análisis , Somatomedinas/metabolismo , Humanos , Peso Molecular , Proteínas Tirosina Quinasas/análisis , Receptores de Somatomedina , Células Tumorales Cultivadas/análisis
13.
Neuroscience ; 136(1): 259-67, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16182452

RESUMEN

Many patients display elevated levels of serum cortisol following acute ischemic stroke. Given that glucocorticoids may potentiate some forms of insult, these studies examined the effects of corticosterone or dexamethasone exposure on cytotoxicity following oxygen-glucose deprivation in the cerebellum, a brain region susceptible to stroke. In organotypic cerebellar slice cultures prepared from neonatal rat pups, 90-min of oxygen-glucose deprivation at 15 days in vitro resulted in significant cytotoxicity at 24-, 48-, and 72-h post-oxygen-glucose deprivation, as measured by uptake of propidium iodide. Exposure of cultures following oxygen-glucose deprivation to the antioxidant trolox (500 microM), but not to the glucocorticoid receptor antagonist RU486 (10 microM), completely blocked oxygen-glucose deprivation-induced cytotoxicity. Corticosterone (1 microM) or dexamethasone (10 microM) exposure alone did not significantly increase propidium iodide uptake above levels observed in control cultures. However, corticosterone or dexamethasone exposure after oxygen-glucose deprivation potentiated oxygen-glucose deprivation-mediated propidium iodide uptake at each time point. Trolox, as well as RU486, co-exposure of cultures to corticosterone or dexamethasone after oxygen-glucose deprivation abolished all cytotoxicity. In conclusion, these data demonstrated that glucocorticoid exposure modulated oxygen-glucose deprivation-mediated propidium iodide uptake, which likely involved glucocorticoid receptor activation and pro-oxidant effects.


Asunto(s)
Cerebelo/efectos de los fármacos , Cerebelo/fisiopatología , Corticosterona/farmacología , Dexametasona/farmacología , Glucosa/deficiencia , Hipoxia/fisiopatología , Animales , Antioxidantes/farmacología , Muerte Celular/efectos de los fármacos , Cerebelo/metabolismo , Cromanos/farmacología , Sinergismo Farmacológico , Femenino , Técnicas In Vitro , Masculino , Mifepristona/farmacología , Propidio/farmacocinética , Ratas , Ratas Sprague-Dawley
14.
Cell Signal ; 1(2): 195-204, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2484434

RESUMEN

Insulin elicits the autophosphorylation of the beta-subunit of its receptor on tyrosine residues: this effect appears to be the earliest post-binding event involved in insulin action. In the present study we have raised highly specific antibodies to phosphotyrosine residues, and we have taken advantage of these antibodies to further evaluate the role of the insulin receptor tyrosine kinase in the generation of insulin's biological responses. Using a cell-free phosphorylation assay, we show here that these antibodies increase the tyrosine kinase activity of the receptor, and its phosphorylation on tyrosine residues. In contrast, the antibodies do not interfere with dephosphorylation of the insulin receptor. Introduction of the same antibodies in living Fao hepatoma cells enhances the effect of insulin on both glucose transport and aminoacid uptake. As a whole our data indicate that the insulin receptor kinase is involved in the generation of an early (glucose transport) and late (aminoacid uptake) response to insulin. Further, conformational changes in phosphotyrosine containing domains of the insulin receptor appear to modulate insulin's biological effects. Finally, the injection of antibodies in intact cells provides us with a novel and promising tool to search for cellular substrates for the insulin receptor tyrosine kinase.


Asunto(s)
Insulina/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Tirosina/análogos & derivados , Aminoácidos/metabolismo , Animales , Anticuerpos , Especificidad de Anticuerpos , Transporte Biológico , Sistema Libre de Células , Glucosa/metabolismo , Neoplasias Hepáticas Experimentales , Fosforilación , Fosfotirosina , Ratas , Receptor de Insulina , Células Tumorales Cultivadas , Tirosina/inmunología , Tirosina/metabolismo
16.
J Bone Miner Res ; 13(7): 1101-11, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9661074

RESUMEN

We have used homologous recombination in embryonic stem cells to generate mice with a targeted disruption of the osteopontin (Opn, or Spp1, for secreted phosphoprotein 1) gene. Mice homozygous for this disruption fail to express osteopontin (OPN) as assessed at both the mRNA and protein level, although an N-terminal fragment of OPN is detectable at extremely low levels in the bones of -/- animals. The Opn -/- mice are fertile, their litter size is normal, and they develop normally. The bones and teeth of animals not expressing OPN are morphologically normal at the level of light and electron microscopy, and the skeletal structure of young animals is normal as assessed by radiography. Ultrastructurally, proteinaceous structures normally rich in OPN, such as cement lines, persist in the bones of the Opn-/- animals. Osteoclastogenesis was assessed in vitro in cocultures with a feeder layer of calvarial osteoblast cells from wild-type mice. Spleen cells from Opn-/- mice cells formed osteoclasts 3- to 13-fold more frequently than did control Opn+/+ cells, while the extent of osteoclast development from Opn -/- bone marrow cells was about 2- to 4-fold more than from the corresponding wild-type cells. Osteoclast development occurred when Opn-/- spleen cells were differentiated in the presence of Opn-/-osteoblasts, indicating that endogenous OPN is not required for this process. These results suggest that OPN is not essential for normal mouse development and osteogenesis, but can modulate osteoclast differentiation.


Asunto(s)
Desarrollo Óseo/fisiología , Osteoclastos/fisiología , Sialoglicoproteínas/deficiencia , Diente/crecimiento & desarrollo , Animales , Densidad Ósea , Huesos/diagnóstico por imagen , Huesos/ultraestructura , Diferenciación Celular/genética , Técnicas de Cocultivo , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Osteoblastos , Osteoclastos/ultraestructura , Osteopontina , ARN Mensajero/análisis , Radiografía , Sialoglicoproteínas/análisis , Sialoglicoproteínas/genética , Bazo/citología , Diente/ultraestructura
17.
Int J Biochem Cell Biol ; 32(6): 665-75, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10785363

RESUMEN

In our previous work (J. Palyga, Genetic polymorphisms of histone H1. b in duck erythrocytes. Hereditas 114, 85-89, 1991) we reported a genetic polymorphism of duck erythrocyte histone H1.b. Here, we screened H1 preparations in a two-dimensional polyacrylamide gel to refine the distribution of allelic forms of H1.b in fifteen duck populations. We have revealed that the frequency of H1.b allelic variants was significantly different among many conservative and breeding duck groups. While b(1) and b(3) were common in all populations screened, the allele b(2), with a slightly lower apparent molecular weight, was confined mainly to brown-feathered ducks (Khaki Campbell and Orpington) and descendent lines. The C- and N-terminal peptides released upon cleavage with N-bromosuccinimide and Staphylococcus aureus protease V8 from duck allelic histones H1. b2 and H1.b3, respectively, migrated differently in the gel, probably as a result of potential amino acid variation in a C-terminal domain.


Asunto(s)
Alelos , Eritrocitos/metabolismo , Variación Genética , Histonas/genética , Animales , Patos , Histonas/clasificación
18.
FEBS Lett ; 172(1): 87-90, 1984 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-6428937

RESUMEN

In rat brain cortex synaptosomes insulin stimulated the phosphorylation of its own receptor beta-subunit (94 kDa) as identified by immunoprecipitation with anti-insulin or anti-receptor antiserum. The receptor alpha-subunit (115 kDa) was characterized by specific labeling with 125I-labeled photoreactive insulin. These observations indicate that: (i) insulin receptors in brain are composed of alpha-subunits which bind insulin, and beta-subunits, the phosphorylation of which can be stimulated by insulin; (ii) the size of alpha-subunits in brain is significantly smaller than in other tissues (115 vs 130 kDa), whereas beta-subunits (94 kDa) are identical. We suggest that brain insulin receptors represent a subtype regarding their binding function, whereas their enzyme function is more conserved.


Asunto(s)
Corteza Cerebral/metabolismo , Insulina/farmacología , Receptor de Insulina/metabolismo , Marcadores de Afinidad/metabolismo , Animales , Azidas/metabolismo , Ácido Edético/farmacología , Electroforesis en Gel de Poliacrilamida , Femenino , Insulina/análogos & derivados , Insulina/metabolismo , Anticuerpos Insulínicos , Sustancias Macromoleculares , Fosforilación , Ratas , Ratas Endogámicas , Solubilidad , Sinaptosomas/metabolismo , Péptido Intestinal Vasoactivo/farmacología
19.
Biochimie ; 67(10-11): 1119-24, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3000460

RESUMEN

The insulin receptor appears as a tetrameric glycoprotein consisting of two Mr 130,000 subunits (alpha), and two Mr 95,000 subunits (beta) in a disulfide-linked complex. Insulin bound to its specific cell surface receptors in its target cells leads to a complex array of molecular events resulting in insulin effects. It is now generally believed that protein phosphorylation-dephosphorylation reactions represent an important mechanism by which a variety of extracellular stimuli regulate cellular functions. Insulin mediates such reactions, but it is not known whether these are the biochemical link between the binding of insulin to its receptor and its final cellular effects. In search of initial post-binding events which might play a role in insulin action, we looked for phosphorylation of insulin receptors. We show that the insulin receptor displays two functional domains, an insulin binding alpha-subunit, and an insulin responsive protein kinase contained in the beta-subunit. We envisage the insulin receptor as an integrated system for transmembrane signal transmission in which hormone binding to the alpha-subunit leads to activation of the beta-subunit via conformational changes.


Asunto(s)
Proteínas Tirosina Quinasas/metabolismo , Receptor de Insulina/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Sitios de Unión , Sistema Libre de Células , Electroforesis en Gel de Poliacrilamida , Técnicas de Inmunoadsorción , Insulina/metabolismo , Insulina/farmacología , Hígado/metabolismo , Sustancias Macromoleculares , Peso Molecular , Fosfatos/metabolismo , Fosforilación , Ratas , Receptor de Insulina/efectos de los fármacos , Serina/metabolismo , Treonina/metabolismo , Tirosina/metabolismo
20.
Placenta ; 21(4): 345-53, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10833369

RESUMEN

Leukaemia inhibitory factor (LIF) and interleukin-6 (IL-6) are candidate embryo-maternal signalling molecules which are present within the uterine luminal micro-environment. We examined the relative expression of the mRNAs encoding LIF and IL-6, as well as the LIF-binding subunit (LIFR-beta) of the LIF receptor and, as a potential downstream cytokine-responsive gene, beta(2)-microglobulin (beta(2)m), in porcine peri-implantation conceptuses, and in placenta and endometrium during early and mid-pregnancy. Peri-implantation spherical and filamentous conceptuses expressed LIFR-beta and beta(2)m mRNAs with no LIF mRNA present. Rapid development in days 11/12 spherical conceptuses to the filamentous stage was accompanied by transiently increased IL-6 gene expression. The corresponding endometrium, in contrast, expressed LIF in addition to these other mRNAs. LIFR-beta, IL-6 and beta(2)m, but not LIF mRNAs, were expressed in the Jag-1 cell line, an in vitro model for porcine day 14 trophoblast. The greatest steady-state amounts of LIF, LIFR-beta and IL-6 mRNAs in both the endometrium and placenta were evident at the post-implantation stages (days 30 and 60>day 18 of pregnancy). Treatment of porcine endometrial explants with human recombinant (hr)LIF or hrIL-6 resulted in no change in, or diminished, the presence of endometrial beta(2)m mRNA, respectively. Addition of LIF to peri-implantation conceptus explant cultures, in contrast, induced beta(2)m mRNA synthesis. These results highlight the potential importance of both the endometrium and placenta as sources, as well as targets, of these cytokines throughout pregnancy. Cytokine modulation of beta(2)m, a known in vitro mitogen, may constitute one mechanism for local control of trophoblast and endometrial proliferation.


Asunto(s)
Embrión de Mamíferos/metabolismo , Endometrio/metabolismo , Inhibidores de Crecimiento/genética , Interleucina-6/genética , Linfocinas/genética , Placenta/metabolismo , ARN Mensajero/biosíntesis , Receptores de Citocinas/genética , Animales , Línea Celular , Clonación Molecular , Cartilla de ADN/química , Embrión de Mamíferos/citología , Endometrio/citología , Endometrio/efectos de los fármacos , Femenino , Expresión Génica , Inhibidores de Crecimiento/biosíntesis , Inhibidores de Crecimiento/farmacología , Humanos , Interleucina-6/biosíntesis , Interleucina-6/farmacología , Factor Inhibidor de Leucemia , Subunidad alfa del Receptor del Factor Inhibidor de Leucemia , Linfocinas/biosíntesis , Linfocinas/farmacología , Datos de Secuencia Molecular , Embarazo , Receptores de Citocinas/biosíntesis , Receptores OSM-LIF , Proteínas Recombinantes/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Porcinos , Microglobulina beta-2/biosíntesis , Microglobulina beta-2/genética
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