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1.
Br J Cancer ; 110(4): 882-7, 2014 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-24423918

RESUMEN

BACKGROUND: Gallbladder cancers and cholangiocarcinomas make up a heterogenous group of tumours with a poor prognosis in advanced stages. On the basis of evidence of dysregulation of the epidermal growth factor receptor, vascular endothelial growth factor and mitogen-activated protein kinase pathways in biliary cancers, we performed a phase 2 trial of sorafenib and erlotinib in patients with advanced biliary cancers. METHODS: Eligible patients were previously untreated in the advanced setting with adequate hepatic and bone marrow function. Sorafenib and erlotinib were administered continuously at 400 mg BID and 100 mg daily, respectively. RESULTS: Thirty-four eligible patients were recruited. The study was terminated after the first stage of accrual owing to failure to meet the predetermined number of patients who were alive and progression free at 4 months. There were two unconfirmed partial responses (6%, 95% CI: 1-20%), with a median progression-free survival of 2 months (95% CI: 2-3), and median overall survival of 6 months (95% CI: 3-8 months). Grade 3 and 4 adverse events included hypertension, AST/ALT increase, bilirubin increase, diarrhoea, hypokalaemia, hypophosphatemia and rash. CONCLUSIONS: Despite compelling preclinical rationale, the combination of sorafenib and erlotinib does not have promising clinical activity in an unselected population of patients with biliary cancers. Improved patient selection based on tumour biology and molecular markers is critical for future evaluation of targeted therapies in this disease.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias de los Conductos Biliares/tratamiento farmacológico , Conductos Biliares Intrahepáticos , Colangiocarcinoma/tratamiento farmacológico , Neoplasias de la Vesícula Biliar/tratamiento farmacológico , Niacinamida/análogos & derivados , Compuestos de Fenilurea/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Quinazolinas/uso terapéutico , Anciano , Anciano de 80 o más Años , Neoplasias de los Conductos Biliares/mortalidad , Colangiocarcinoma/mortalidad , Supervivencia sin Enfermedad , Receptores ErbB/antagonistas & inhibidores , Clorhidrato de Erlotinib , Femenino , Neoplasias de la Vesícula Biliar/mortalidad , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Persona de Mediana Edad , Niacinamida/efectos adversos , Niacinamida/uso terapéutico , Compuestos de Fenilurea/efectos adversos , Inhibidores de Proteínas Quinasas/efectos adversos , Quinazolinas/efectos adversos , Sorafenib , Insuficiencia del Tratamiento , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores
3.
Brain Behav Immun ; 33: 153-63, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23880236

RESUMEN

The prevalence of neurodevelopmental disorders such as autism is increasing, however the etiology of these disorders is unclear and thought to involve a combination of genetic, environmental and immune factors. A recent epidemiological study found that gestational viral exposure during the first trimester increases risk of autism in offspring by twofold. In mice gestational viral exposures alter behavior of offspring, but the biological mechanisms which underpin these behavioral changes are unclear. We hypothesized that gestational viral exposure induces changes in affiliative hormones, brainstem autonomic nuclei and neurotransmitters which are associated with behavioral alterations in offspring. To address this hypothesis, we exposed pregnant mice to influenza A virus (H3N2) on gestational day 9 and determined behavioral, hormonal and brainstem changes in male and female offspring. We found that gestational flu exposure induced dose-dependent alterations in social and aggressive behaviors (p≤0.05) in male and female offspring and increases in locomotor behaviors particularly in male offspring (p≤0.05). We found that flu exposure was also associated with reductions in oxytocin and serotonin (p≤0.05) levels in male and female offspring and sex-specific changes in dopamine metabolism. In addition we found changes in catecholaminergic and microglia density in brainstem tissues of male flu exposed offspring only (p≤0.05). This study demonstrates that gestational viral exposure induces behavioral changes in mice, which are associated with alterations in affiliative hormones. In addition we found sex-specific changes in locomotor behavior, which may be associated with sex-specific alterations in dopamine metabolism and brainstem inflammation. Further investigations into maternal immune responses are necessary to unravel the molecular mechanisms which underpin abnormal hormonal, immune and behavioral responses in offspring after gestational viral exposure.


Asunto(s)
Trastorno Autístico/etiología , Tronco Encefálico/inmunología , Tronco Encefálico/patología , Subtipo H3N2 del Virus de la Influenza A , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/patología , Oxitocina/sangre , Testosterona/sangre , Animales , Trastorno Autístico/inmunología , Trastorno Autístico/patología , Glucemia/análisis , Peso Corporal/inmunología , Tronco Encefálico/virología , Cromatografía Líquida de Alta Presión , Femenino , Inflamación/inmunología , Inflamación/patología , Inflamación/virología , Masculino , Exposición Materna/efectos adversos , Ratones , Ratones Endogámicos BALB C , Actividad Motora/inmunología , Infecciones por Orthomyxoviridae/complicaciones , Proyectos Piloto , Embarazo , Distribución Aleatoria , Conducta Estereotipada
4.
Transpl Infect Dis ; 15(4): 400-4, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23647866

RESUMEN

BACKGROUND: We sought to assess the prevalence and risk factors for high-risk human papillomavirus (HPV) infection among female liver transplant (LT) candidates. Traditional health screening before LT listing has included Pap smear and is typically carried out by the patient's local provider. The prevalence of high-risk HPV in this population has not been studied. METHODS: With Institutional Review Board approval, 62 LT candidates received a liquid-based Pap smear with high-risk HPV testing as part of their pre-transplant evaluation by a single provider. Clinical variables included age, ethnicity, insurance status, prior Pap smear, and HPV results, HPV risk factors including age of first intercourse, number of lifetime partners, last sexual activity, smoking, birth control pill use, history of sexually transmitted infections, human immunodeficiency virus status, immunosuppressive medication, medical diagnoses, prescribed medications, and history of hepatitis A, B, C, or D. RESULTS: The 62 women had a median age of 56 years, and 39% had high-risk behavior known to be associated with HPV. Ten of 62 patients (16.1%) had high-risk HPV at baseline screening, 5 of whom had atypical cytology. All of the patients who were positive for high-risk HPV had an etiology of hepatitis C virus (HCV) as the underlying cause of liver disease, with the majority (90%) having no history of high-risk behavior for HPV. In contrast, all patients with high-risk behavior who were HCV negative were HPV negative. Fisher's exact test demonstrated a statistically significant relationship between HPV and HCV; odds ratio = 24.4, 95% confidence interval, 1.4, 438.7, P-value = 0.0013. None of the other potential risk factors were associated with HPV in this cohort. CONCLUSIONS: In this study, we provide evidence of a strong association between HCV and HPV in LT candidates, which has not been previously reported. HPV positivity was observed in non-sexually active women, suggesting a reactivation of dormant HPV. An association between hepatitis C and high-risk HPV could involve impairment of T-cell function by hepatitis C. These data support close surveillance in women's health screening for LT candidates. Further studies to characterize immune responses in these patients will be in order.


Asunto(s)
Hepatitis C/complicaciones , Hepatitis C/epidemiología , Trasplante de Hígado , Papillomaviridae , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/epidemiología , Adulto , Anciano , Femenino , Hepacivirus , Hepatitis C/virología , Humanos , Persona de Mediana Edad , Prueba de Papanicolaou , Infecciones por Papillomavirus/virología , Prevalencia , Factores de Riesgo , Frotis Vaginal
5.
Gesundheitswesen ; 74(1): e1-8, 2012 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-21879465

RESUMEN

In the preceding decades a new perspective on the role of patients in the health-care system has gained ground, considering patients not merely as "suffering persons" but additionally as "customers". Physicians, however, tend to disagree with this approach because of the economic connotation of the term customer. Until now, there is only poor evidence of whether students of medicine - who are going to work as physicians in the future - agree or disagree with that approach and whether they are ready to accept patients as customers. In the following study students of medicine were interviewed on their perspectives towards that approach, in particular on their attitudes towards the idea of "the patient as customer", the appropriateness of the term consumer in different clinical settings and sectors of health care, the implementation of consumer orientation in clinical routine, and their favoured model of physician-patient relationship.As the study could not build upon data of prior similar studies, a quantitative and qualitative cross-sectional study with a descriptive-explorative design was conducted. Using a semi-standardised questionnaire, 313 medical students (response rate: 95%) were interviewed in Spring 2010. At the time of the survey, the students were enrolled at the faculty of medicine at Freiburg University, Germany, and were in their last semester which immediately preceded their exam.The future physicians do not consider patients primarily as customers. More than 80% of the respondents "absolutely" or "largely" supported the idea that patients are considerably more than customers. The analysis of the qualitative data of the study shows different results. Here, more statements were made that patients could equally be seen as customers (449 students supported this idea, 298 did not). Statements contradicting the customer approach referred mostly to the asymmetry of the physician-patient relationship and the special role of the patient. The highest level of acceptance of the customer approach was found in classical service settings such as pharmacies, the lowest level in emergency medical aid. According to medical students, a consumer orientation has been realised in different health service areas in correspondingly different degrees: On top of the list are plastic surgery clinics, followed by private health insurances and homeopathic clinics. A minority of medical students predict the implementation of consumer orientation in the emergency medical aid. Future physicians consider their relationship to patients largely as a relationship between a healing person and a person seeking help rather than a relationship between a service provider and a customer.Considering recent developments in the organisation of medical services and health services in general, it becomes increasingly important to know what kind of 'service behaviour' patients expect from their doctors and other health providers. Obviously, it is not self-evident for medical students to perceive their future patients as customers and to act as customer-oriented 'service providers'. In view of this, the faculties of medicine at universities - which provide professional training to students of medicine - should be aware of the challenge to 'socialise' their students so that they can keep up with patients' expectations.


Asunto(s)
Actitud del Personal de Salud , Defensa del Consumidor , Satisfacción del Paciente , Relaciones Médico-Paciente , Estudiantes de Medicina/estadística & datos numéricos , Alemania , Humanos
6.
Artículo en Alemán | MEDLINE | ID: mdl-23114452

RESUMEN

An integrated health care project called "Gesundes Kinzigtal" was conducted in a rural area in Germany. As part of the project, physicians were trained and other measures were taken to enhance patient involvement in medical decision making. As part of the external evaluation, various effects regarding patient involvement in medical decision making, patient involvement and information preference, decision confidence, patient satisfaction with ambulatory care and patient quality of life were examined. The data were gathered by means of a questionnaire on an annual basis between 2007 and 2009. Effects were compared between patients who were participating in the integrated care project and two control groups. Analyses are based on the data of 1,205 patients. Over time all outcomes decreased slightly, except for information preference and physical quality of life. No statistically significant intervention effects on patient involvement in medical decision making or any other outcome variable could be found. The intensity of the training was presumably too low to establish an enduring change in the physician-patient interaction.


Asunto(s)
Toma de Decisiones , Prestación Integrada de Atención de Salud , Promoción de la Salud , Participación del Paciente , Salud Rural , Atención Ambulatoria , Estudios de Cohortes , Comunicación , Educación Médica Continua , Alemania , Humanos , Educación del Paciente como Asunto , Satisfacción del Paciente , Relaciones Médico-Paciente , Evaluación de Programas y Proyectos de Salud , Calidad de Vida
7.
J Breath Res ; 16(2)2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35120338

RESUMEN

Cystic fibrosis (CF) is characterized by chronic respiratory infections which progressively decrease lung function over time. Affected individuals experience episodes of intensified respiratory symptoms called pulmonary exacerbations (PEx), which in turn accelerate pulmonary function decline and decrease survival rate. An overarching challenge is that there is no standard classification for PEx, which results in treatments that are heterogeneous. Improving PEx classification and management is a significant research priority for people with CF. Previous studies have shown volatile organic compounds (VOCs) in exhaled breath can be used as biomarkers because they are products of metabolic pathways dysregulated by different diseases. To provide insights on PEx classification and other CF clinical factors, exhaled breath samples were collected from 18 subjects with CF, with some experiencing PEx and others serving as a baseline. Exhaled breath was collected in Tedlar bags during tidal breathing and cryotransferred to headspace vials for VOC analysis by solid phase microextraction coupled to gas chromatography-mass spectrometry. Statistical significance testing between quantitative and categorical clinical variables displayed percent-predicted forced expiratory volume in one second (FEV1pp) was decreased in subjects experiencing PEx. VOCs correlating with other clinical variables (body mass index, age, use of highly effective modulator treatment (HEMT), and the need for inhaled tobramycin) were also explored. Two volatile aldehydes (octanal and nonanal) were upregulated in patients not taking the HEMT. VOCs correlating to potential confounding variables were removed and then analyzed by regression for significant correlations with FEV1pp measurements. Interestingly, the VOC with the highest correlation with FEV1pp (3,7-dimethyldecane) also gave the lowestp-value when comparing subjects at baseline and during PEx. Other VOCs that were differentially expressed due to PEx that were identified in this study include durene, 2,4,4-trimethyl-1,3-pentanediol 1-isobutyrate and 5-methyltridecane. Receiver operator characteristic curves were developed and showed 3,7-dimethyldecane had higher ability to classify PEx (area under the curve (AUC) = 0.91) relative to FEV1pp values at collection (AUC = 0.83). However, normalized ΔFEV1pp values had the highest capability to distinguish PEx (AUC = 0.93). These results show that VOCs in exhaled breath may be a rich source of biomarkers for various clinical traits of CF, including PEx, that should be explored in larger sample cohorts and validation studies.


Asunto(s)
Fibrosis Quística , Compuestos Orgánicos Volátiles , Pruebas Respiratorias/métodos , Fibrosis Quística/diagnóstico , Humanos , Pulmón/metabolismo , Proyectos Piloto , Compuestos Orgánicos Volátiles/análisis
8.
Nat Commun ; 12(1): 2951, 2021 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-34012031

RESUMEN

The muscular dystrophies encompass a broad range of pathologies with varied clinical outcomes. In the case of patients carrying defects in fukutin-related protein (FKRP), these diverse pathologies arise from mutations within the same gene. This is surprising as FKRP is a glycosyltransferase, whose only identified function is to transfer ribitol-5-phosphate to α-dystroglycan (α-DG). Although this modification is critical for extracellular matrix attachment, α-DG's glycosylation status relates poorly to disease severity, suggesting the existence of unidentified FKRP targets. Here we reveal that FKRP directs sialylation of fibronectin, a process essential for collagen recruitment to the muscle basement membrane. Thus, our results reveal that FKRP simultaneously regulates the two major muscle-ECM linkages essential for fibre survival, and establishes a new disease axis for the muscular dystrophies.


Asunto(s)
Fibronectinas/metabolismo , Glicosiltransferasas/metabolismo , Distrofias Musculares/metabolismo , Distrofias Musculares/patología , Distrofia Muscular Animal/metabolismo , Distrofia Muscular Animal/patología , Pentosiltransferasa/metabolismo , Proteínas de Pez Cebra/metabolismo , Animales , Membrana Basal/metabolismo , Membrana Basal/patología , Línea Celular , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Glicosilación , Glicosiltransferasas/deficiencia , Glicosiltransferasas/genética , Humanos , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Distrofias Musculares/genética , Distrofia Muscular de Cinturas/genética , Distrofia Muscular de Cinturas/metabolismo , Distrofia Muscular de Cinturas/patología , Distrofia Muscular Animal/genética , Mutación , Mioblastos Esqueléticos/metabolismo , Mioblastos Esqueléticos/patología , Pentosiltransferasa/deficiencia , Pentosiltransferasa/genética , Fenotipo , Pez Cebra , Proteínas de Pez Cebra/deficiencia , Proteínas de Pez Cebra/genética
9.
Caries Res ; 44(6): 571-8, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21088402

RESUMEN

Hyposalivation is often associated with high caries activity, in particular in patients undergoing irradiation in the head/neck area. Besides the use of saliva substitutes to relieve the oral symptoms, daily application of fluoride gels or toothpaste (5,000 µg F⁻/g) is recommended for caries prevention. The aim of this study was to evaluate potentially remineralising effects of these fluoride agents in combination with saliva substitutes on enamel subsurface lesions. Demineralised bovine specimens were either stored in mineral water [control; saturation with respect to octacalcium phosphate (S(OCP)): 0.8], a demineralising saliva substitute (Glandosane; S(OCP): 0.3) or in a modified (with respect to S(OCP)) saliva substitute [Saliva natura (SN); S(OCP): 1.9] for 5 weeks (37°C). The following treatments were applied twice daily (11-13/group): no treatment (0), ProSchmelz fluoride gel (PS; 10 min application), Duraphat toothpaste (DP; 10 s; brushing with toothpaste/storage solution slurry), combination of DP+PS. Mineral parameters before/after storage were evaluated from microradiographs. Storage in Glandosane led to significant demineralisation (p < 0.05; paired t test), whereas additional use of fluoride agents neutralised the demineralising effect (p > 0.05). Storage in water alone resulted in no changes in mineral parameters (p > 0.05), whereas in combination with fluorides remineralisation could be shown (p < 0.05). For SN alone, remineralisation was observed (p < 0.05), but no additional beneficial effects of fluorides were detected. Under the conditions chosen, the fluoride agents reduce the demineralising effects of Glandosane and promote the remineralisation of specimens stored in water. Remineralising effects of SN could not be enhanced by the fluorides.


Asunto(s)
Esmalte Dental/efectos de los fármacos , Fluoruros Tópicos/farmacología , Saliva Artificial/farmacología , Remineralización Dental/métodos , Cepillado Dental , Animales , Bovinos , Esmalte Dental/patología , Distribución Aleatoria , Saliva Artificial/química
10.
Neurosurg Rev ; 33(1): 47-51, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19760287

RESUMEN

Cavernous malformations (CCMs) are benign, well-circumscribed, and mulberry-like vascular malformations that may be found in the central nervous system in up to 0.5% of the population. Cavernous malformations can be sporadic or inherited. The common symptoms are epilepsy, hemorrhages, focal neurological deficits, and headaches. However, CCMs are often asymptomatic. The familiar form is associated with three gene loci, namely 7q21-q22 (CCM1), 7p13-p15 (CCM2), and 3q25.2-q27 (CCM3) and is inherited as an autosomal dominant trait with incomplete penetrance. The CCM genes are identified as Krit 1 (CCM1), MGC4607 (CCM2), and PDCD10 (CCM3). Here, we present the clinical and genetic features of CCMs in 19 Swiss families. Furthermore, surgical aspects in such families are also discussed.


Asunto(s)
Malformaciones Arteriovenosas Intracraneales/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Femenino , Asesoramiento Genético , Humanos , Malformaciones Arteriovenosas Intracraneales/patología , Malformaciones Arteriovenosas Intracraneales/terapia , Masculino , Persona de Mediana Edad , Mutación Missense/fisiología , Suiza , Resultado del Tratamiento , Adulto Joven
11.
J Cell Biol ; 109(6 Pt 1): 2761-9, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2592405

RESUMEN

The prespore vesicle (PSV) is an organelle which secretes spore coat proteins and gal/galNAc polysaccharides from prespore cells of Dictyostelium. By combining the techniques of protein A-gold immunocytochemistry and ricin-gold affinity cytochemistry we have demonstrated colocalization of the lysosomal enzyme alpha-mannosidase with gal/galNAc polysaccharides in prespore vesicles and the spore coat. To determine the origin of prespore vesicles a series of pulse-chase experiments were performed. Cells were labeled with [35S]methionine or [35S]sulfate at different times during development and allowed to differentiate in the presence of unlabeled methionine or sulfate for various periods of time. The cells were homogenized and intracellular organelles were separated using Percoll density gradient centrifugation. The distribution of [35S]methionine-labeled alpha-mannosidase and [35S]sulfate-labeled glycoproteins in the Percoll gradients was determined. It was found that prespore vesicles contained protein which was previously found in lysosomes. Newly labeled protein also entered these vesicles. The data suggest that developing Dictyostelium cells either restructure preexisting lysosomes into prespore vesicles or transport protein between these two organelles. We propose that secretory granules and lysosomes may have a common biosynthetic origin and may be evolutionarily related.


Asunto(s)
Gránulos Citoplasmáticos/enzimología , Dictyostelium/enzimología , Manosidasas/metabolismo , Gránulos Citoplasmáticos/ultraestructura , Dictyostelium/crecimiento & desarrollo , Dictyostelium/ultraestructura , Glicoproteínas/biosíntesis , Lisosomas/enzimología , Lisosomas/ultraestructura , Manosidasas/biosíntesis , Microscopía Electrónica , Peso Molecular , alfa-Manosidasa
12.
J Cell Biol ; 146(3): 531-42, 1999 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-10444063

RESUMEN

To study the possible role of the nuclear matrix in chromosome territory organization, normal human fibroblast cells are treated in situ via classic isolation procedures for nuclear matrix in the absence of nuclease (e.g., DNase I) digestion, followed by chromosome painting. We report for the first time that chromosome territories are maintained intact on the nuclear matrix. In contrast, complete extraction of the internal nuclear matrix components with RNase treatment followed by 2 M NaCl results in the disruption of higher order chromosome territory architecture. Correlative with territorial disruption is the formation of a faint DNA halo surrounding the nuclear lamina and a dispersive effect on the characteristically discrete DNA replication sites in the nuclear interior. Identical results were obtained using eight different human chromosome paints. Based on these findings, we developed a fractionation strategy to release the bulk of nuclear matrix proteins under conditions where the chromosome territories are maintained intact. A second treatment results in disruption of the chromosome territories in conjunction with the release of a small subset of acidic proteins. These proteins are distinct from the major nuclear matrix proteins and may be involved in mediating chromosome territory organization.


Asunto(s)
Cromosomas Humanos/metabolismo , Matriz Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Sulfato de Amonio/farmacología , Línea Celular , Núcleo Celular/efectos de los fármacos , Núcleo Celular/genética , Núcleo Celular/metabolismo , Núcleo Celular/ultraestructura , Pintura Cromosómica , Cromosomas Humanos/efectos de los fármacos , Cromosomas Humanos/genética , Cromosomas Humanos/ultraestructura , ADN/genética , ADN/ultraestructura , Replicación del ADN/genética , Disulfuros/metabolismo , Electroforesis en Gel Bidimensional , Fibroblastos/citología , Fibroblastos/metabolismo , Fibroblastos/ultraestructura , Humanos , Microscopía Electrónica , Microscopía Fluorescente , Peso Molecular , Matriz Nuclear/efectos de los fármacos , Matriz Nuclear/genética , Matriz Nuclear/ultraestructura , Proteínas Nucleares/análisis , Concentración Osmolar , Ribonucleasa Pancreática/metabolismo , Cloruro de Sodio/farmacología
13.
Science ; 151(3714): 1098-101, 1966 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-17739592

RESUMEN

Amino acids dissolved in salt solutions may be concentrated and removed from the solution by ligand exchange on copper-Chelex 100 resin. Competing inorganic ligands do not interfere, and ion exchange with cations does not occur; thus loss of metal ion from this column is avoided. To test the potentiality of ligand exchange for chromatography, the type and nature of the dissolved amino compounds in sea water were investigated. The data revealed that the bulk of the dissolved amino compounds is present in a combined rather than a free state.

14.
Science ; 179(4074): 682-3, 1973 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-17774107

RESUMEN

Ten Nicotiana species were assayed for the proportion of DNA that is complementary to ribosomal RNA. This proportion varies from 0.27 to 0.9 percent, with tetraploid species having lower values than the diploid species. The tetraploid species have about twice as much DNA per cell as do diploid species. Thus, the absolute number of genes for ribosomal RNA varies less than the proportion of complementary DNA. Further, the number of genes for the RNA in 80S ribosomes varies less among species than does that for the RNA in 70S ribosomes. The data indicate that loss of DNA complementary to ribosomal RNA is associated with tetraploidy in the genus Nicotiana.

15.
Science ; 281(5382): 1502-6, 1998 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-9727975

RESUMEN

Microscopy shows that individual sites of DNA replication and transcription of mammalian nuclei segregate into sets of roughly 22 and 16 higher order domains, respectively. Each domain set displayed a distinct network-like appearance, including regions of individual domains and interdigitation of domains between the two networks. These data support a dynamic mosaic model for the higher order arrangement of genomic function inside the cell nuclei.


Asunto(s)
Núcleo Celular/metabolismo , Replicación del ADN , Genoma , Transcripción Genética , Células 3T3 , Animales , Línea Celular , Nucléolo Celular/metabolismo , Nucléolo Celular/ultraestructura , Núcleo Celular/ultraestructura , Genoma Humano , Humanos , Procesamiento de Imagen Asistido por Computador , Ratones , Microscopía Confocal , Modelos Biológicos , Fase S
16.
J Theor Biol ; 261(2): 266-78, 2009 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-19635486

RESUMEN

The purpose of this study is to identify the hierarchy of importance amongst pathways involved in fatty acid (FA) metabolism and their regulators in the control of hepatic FA composition. A modeling approach was applied to experimental data obtained during fasting in PPARalpha knockout (KO) mice and wild-type mice. A step-by-step procedure was used in which a very simple model was completed by additional pathways until the model fitted correctly the measured quantities of FA in the liver. The resulting model included FA uptake by the liver, FA oxidation, elongation and desaturation of FA, which were found active in both genotypes during fasting. From the model analysis we concluded that PPARalpha had a strong effect on FA oxidation. There were no indications that this effect changes during the fasting period, and it was thus considered to be constant. In PPARalpha KO mice, FA uptake was identified as the main pathway responsible for FA variation in the liver. The models showed that FA were oxidized at a constant and small rate, whereas desaturation of FA also occurred during fasting. The latter observation was rather unexpected, but was confirmed experimentally by the measurement of delta-6-desaturase mRNA using real-time quantitative PCR (QPCR). These results confirm that mathematical models can be a useful tool in identifying new biological hypotheses and nutritional routes in metabolism.


Asunto(s)
Ayuno/metabolismo , Ácidos Grasos/metabolismo , Hígado/metabolismo , Modelos Biológicos , PPAR alfa/fisiología , Animales , Regulación de la Expresión Génica/fisiología , Genotipo , Linoleoil-CoA Desaturasa/biosíntesis , Linoleoil-CoA Desaturasa/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Oxidación-Reducción , PPAR alfa/deficiencia , Reacción en Cadena de la Polimerasa/métodos , ARN Mensajero/genética
17.
Am J Bioeth ; 9(5): 31-6, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19396681

RESUMEN

The prospect of using cell-based interventions (CBIs) to treat neurological conditions raises several important ethical and policy questions. In this target article, we focus on issues related to the unique constellation of traits that characterize CBIs targeted at the central nervous system. In particular, there is at least a theoretical prospect that these cells will alter the recipients' cognition, mood, and behavior-brain functions that are central to our concept of the self. The potential for such changes, although perhaps remote, is cause for concern and careful ethical analysis. Both to enable better informed consent in the future and as an end in itself, we argue that early human trials of CBIs for neurological conditions must monitor subjects for changes in cognition, mood, and behavior; further, we recommend concrete steps for that monitoring. Such steps will help better characterize the potential risks and benefits of CBIs as they are tested and potentially used for treatment.


Asunto(s)
Afecto , Conducta , Trasplante de Tejido Encefálico/ética , Trasplante de Células/ética , Enfermedades del Sistema Nervioso Central/cirugía , Ensayos Clínicos como Asunto/ética , Cognición , Consentimiento Informado , Investigación Biomédica/ética , Trasplante de Tejido Encefálico/efectos adversos , Trasplante de Células/efectos adversos , Ética en Investigación , Humanos , Pruebas Neuropsicológicas , Sujetos de Investigación , Encuestas y Cuestionarios , Experimentación Humana Terapéutica/ética
18.
J Microsc ; 229(Pt 3): 475-82, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18331498

RESUMEN

Accurate models for the light-scattering form factors of nanoparticles are of crucial importance to characterize the optical properties of the particles and to develop new photonic devices. Analytical or semi-empirical models exist for particles of spherical and cylindrical shape. The angular spectrum of scattering for particles of more complex shape is very complex and can only be obtained by numerical simulations. Moreover, the light scattering of metallic particles depends on many parameters as size, shape, optical constants, substrate and polarization of light. Experimental verification of the differential scattering cross-sections obtained from different calculation methods is always necessary. Measurements done on single nanoparticles are very sensitive to their local properties and the signal-to-noise ratio may be very poor. Arrays of identical particles illuminated by a planes waves produce Bragg diffraction and the resultant patterns depend on the averaged values of the form factors of the particles. In order to test the validity of models for the scattering form factor, we present an experimental setup capable of measuring Bragg diffraction patterns of arrays of nanoparticles in the visible and near-infrared regions of the spectrum. The approach is similar to that of X-ray diffraction of crystals.

19.
Epilepsy Res ; 80(2-3): 158-62, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18485669

RESUMEN

BACKGROUND: Psychiatric disorders may occur in patients with intractable partial epilepsy after surgical treatment. Previous reports attributed the presence of psychological adverse events to specific pathological entities such as dysembryoplastic neuroepithelial tumors (DNETs) and gangliogliomas. The rationale for the present study is to evaluate the importance of the surgical pathology in individuals undergoing epilepsy surgery. METHODS: The patients were separated into three groups based on the surgical pathology: group I ganglioglioma (N=25), group II DNETs (N=25), and group III mesial temporal sclerosis (N=25). Thirteen of the 75 patients (17.3%) had a preexisting psychiatric disorder. The most common preoperative psychiatric diagnosis was depression (N=4). Sixty-three of the lesions (84%) were restricted to the temporal lobe. The operative strategy included resection of the lesion and epileptogenic cortex. Sixty-two of the 75 patients (83%) were rendered seizure-free. RESULTS: Eight of the 75 patients (10.7%) had an acquired psychiatric illness following surgical treatment. A mood disorder developed in three patients after surgery. No statistical difference emerged in preoperative psychiatric co-morbidity (no group difference; p=1.0) or in newly diagnosed postoperative psychiatric disease (group I vs. II, p=0.67; group I vs. III, p=1.0; and group II vs. III, p=0.67) within the three surgical pathology groups. CONCLUSION: This study indicates that the presence of psychiatric disease before and after surgery for intractable partial epilepsy, predominantly of temporal lobe origin, was independent of the pathological findings.


Asunto(s)
Epilepsias Parciales/epidemiología , Epilepsias Parciales/patología , Trastornos Mentales/epidemiología , Trastornos Mentales/etiología , Adolescente , Adulto , Lobectomía Temporal Anterior/efectos adversos , Niño , Comorbilidad , Epilepsias Parciales/cirugía , Femenino , Estudios de Seguimiento , Lateralidad Funcional , Ganglioglioma/epidemiología , Ganglioglioma/patología , Ganglioglioma/cirugía , Humanos , Inteligencia , Pruebas de Inteligencia , Masculino , Trastornos Mentales/patología , Pruebas Neuropsicológicas , Estudios Retrospectivos
20.
J Exp Med ; 214(3): 669-680, 2017 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-28126831

RESUMEN

Nonimmunological connective tissue phenotypes in humans are common among some congenital and acquired allergic diseases. Several of these congenital disorders have been associated with either increased TGF-ß activity or impaired STAT3 activation, suggesting that these pathways might intersect and that their disruption may contribute to atopy. In this study, we show that STAT3 negatively regulates TGF-ß signaling via ERBB2-interacting protein (ERBIN), a SMAD anchor for receptor activation and SMAD2/3 binding protein. Individuals with dominant-negative STAT3 mutations (STAT3mut ) or a loss-of-function mutation in ERBB2IP (ERBB2IPmut ) have evidence of deregulated TGF-ß signaling with increased regulatory T cells and total FOXP3 expression. These naturally occurring mutations, recapitulated in vitro, impair STAT3-ERBIN-SMAD2/3 complex formation and fail to constrain nuclear pSMAD2/3 in response to TGF-ß. In turn, cell-intrinsic deregulation of TGF-ß signaling is associated with increased functional IL-4Rα expression on naive lymphocytes and can induce expression and activation of the IL-4/IL-4Rα/GATA3 axis in vitro. These findings link increased TGF-ß pathway activation in ERBB2IPmut and STAT3mut patient lymphocytes with increased T helper type 2 cytokine expression and elevated IgE.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/fisiología , Hipersensibilidad/inmunología , Factor de Transcripción STAT3/fisiología , Transducción de Señal/fisiología , Factor de Crecimiento Transformador beta/fisiología , Proteínas Adaptadoras Transductoras de Señales/deficiencia , Humanos , Interleucina-4/fisiología , Receptores de Interleucina-4/fisiología , Proteína Smad2/análisis , Proteína Smad2/fisiología , Proteína smad3/análisis , Proteína smad3/fisiología
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