Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Biomedicines ; 11(12)2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-38137564

RESUMEN

Malignant neoplasms, including pancreatic cancer and melanoma, are major global health challenges. This study investigates melanoma pancreatic syndrome, a rare hereditary tumor syndrome associated with CDKN2A gene mutations. CDKN2A mutations contribute to a lifetime risk of melanoma ranging from 28% to 67%. This study reports the clinical features of six individuals with CDKN2A mutations and identifies recurrent alterations such as c.307_308del, c.159G>C and c.71G>C. It highlights the need for CDKN2A mutation testing in suspected cases of familial atypical multiple mole melanoma. Clinically significant variants show associations with melanoma and pancreatic cancer. The challenges of treating individuals with CDKN2A mutations are discussed, and the lack of specific targeted therapies is highlighted. Preclinical studies suggest a potential benefit of CDK4/6 inhibitors, although clinical trials show mixed results. This study underscores the importance of continued research into improved diagnostic and therapeutic strategies to address the complexities of hereditary cancer syndromes.

2.
iScience ; 26(11): 108345, 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-38026226

RESUMEN

Autoimmunity plays a role in certain types of lung fibrosis, notably connective tissue disease-associated interstitial lung disease (CTD-ILD). In idiopathic pulmonary fibrosis (IPF), an incurable and fatal lung disease, diagnosis typically requires clinical exclusion of autoimmunity. However, autoantibodies of unknown significance have been detected in IPF patients. We conducted computational analysis of B cell transcriptomes in published transcriptomics datasets and developed a proteomic Differential Antigen Capture (DAC) assay that captures plasma antibodies followed by affinity purification of lung proteins coupled to mass spectrometry. We analyzed antibody capture in two independent cohorts of IPF and CTL-ILD patients over two disease progression time points. Our findings revealed significant upregulation of specific immunoglobulins with V-segment bias in IPF across multiple cohorts. We identified a predictive autoimmune signature linked to reduced transplant-free survival in IPF, persisting over time. Notably, autoantibodies against thrombospondin-1 were associated with decreased survival, suggesting their potential as predictive biomarkers.

3.
Nat Methods ; 20(10): 1530-1536, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37783884

RESUMEN

Single-cell proteomics by mass spectrometry is emerging as a powerful and unbiased method for the characterization of biological heterogeneity. So far, it has been limited to cultured cells, whereas an expansion of the method to complex tissues would greatly enhance biological insights. Here we describe single-cell Deep Visual Proteomics (scDVP), a technology that integrates high-content imaging, laser microdissection and multiplexed mass spectrometry. scDVP resolves the context-dependent, spatial proteome of murine hepatocytes at a current depth of 1,700 proteins from a cell slice. Half of the proteome was differentially regulated in a spatial manner, with protein levels changing dramatically in proximity to the central vein. We applied machine learning to proteome classes and images, which subsequently inferred the spatial proteome from imaging data alone. scDVP is applicable to healthy and diseased tissues and complements other spatial proteomics and spatial omics technologies.


Asunto(s)
Proteoma , Proteómica , Animales , Ratones , Proteoma/análisis , Espectrometría de Masas/métodos , Proteómica/métodos , Captura por Microdisección con Láser/métodos
4.
Langmuir ; 39(35): 12336-12345, 2023 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-37603287

RESUMEN

Periodic modulation of the deposition angle (PMDA) is a new method to deposit nanostructured and continuous layers with controllable periodic density fluctuation. The method is used for the magnetron sputtering of a WO3 layer for an electrochromic device (ECD). An experimental study indicates that the electrochromic coloration-bleaching rate nearly doubles and the electrochromic efficiency grows by about 25% in comparison with the traditional method. The ECD efficiency rises with the increasing degree of nanostructure ordering, surface roughness, and homogeneity of the WO3 layer. The method is promising for coating deposition techniques needed to produce versatile devices with specific requirements for ion transport in surface layers, coatings, and interfaces, such as fuel cells, batteries, and supercapacitors.

5.
Int J Mol Sci ; 24(9)2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-37175647

RESUMEN

More than 275 million people in the world are carriers of a heterozygous mutation of the CFTR gene, associated with cystic fibrosis, the most common autosomal recessive disease among Caucasians. Some recent studies assessed the association between carriers of CFTR variants and some pathologies, including cancer risk. The aim of this study is to analyze the landscape of germline pathogenic heterozygous CFTR variants in patients with diagnosed malignant neoplasms. For the first time in Russia, we evaluated the frequency of CFTR pathogenic variants by whole-genome sequencing in 1800 patients with cancer and compared this with frequencies of CFTR variants in the control group (1825 people) adjusted for age and 10,000 healthy individuals. In the issue, 47 out of 1800 patients (2.6%) were carriers of CFTR pathogenic genetic variants: 0.028 (42/1525) (2.8%) among breast cancer patients, 0.017 (3/181) (1.7%) among colorectal cancer patients and 0.021 (2/94) (2.1%) among ovarian cancer patients. Pathogenic CFTR variants were found in 52/1825 cases (2.85%) in the control group and 221 (2.21%) in 10,000 healthy individuals. Based on the results of the comparison, there was no significant difference in the frequency and distribution of pathogenic variants of the CFTR gene, which is probably due to the study limitations. Obviously, additional studies are needed to assess the clinical significance of the heterozygous carriage of CFTR pathogenic variants in the development of various pathologies in the future, particularly cancer.


Asunto(s)
Neoplasias de la Mama , Regulador de Conductancia de Transmembrana de Fibrosis Quística , Humanos , Femenino , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Predisposición Genética a la Enfermedad , Mutación , Células Germinativas
6.
Free Radic Biol Med ; 196: 133-144, 2023 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-36649901

RESUMEN

The balance between the mitochondrial respiratory chain activity and the cell's needs in ATP ensures optimal cellular function. Cytochrome c is an essential component of the electron transport chain (ETC), which regulates ETC activity, oxygen consumption, ATP synthesis and can initiate apoptosis. The impact of conformational changes in cytochrome c on its function is not understood for the lack of access to these changes in intact mitochondria. We have developed a novel sensor that uses unique properties of label-free surface-enhanced Raman spectroscopy (SERS) to identify conformational changes in heme of cytochrome c and to elucidate their role in functioning mitochondria. We have verified that molecule bond vibrations assessed by SERS are a reliable indicator of the heme conformation during changes in the inner mitochondrial membrane potential and ETC activity. We have demonstrated that cytochrome c heme reversibly switches between planar and ruffled conformations in response to the inner mitochondrial membrane potential (ΔΨ) and H+ concentration in the intermembrane space. This regulates the efficiency of the mitochondrial respiratory chain, thus, adjusting the mitochondrial respiration to the cell's consumption of ATP and the overall activity. We have found that under hypertensive conditions cytochrome c heme loses its sensitivity to ΔΨ that can affect the regulation of ETC activity. The ability of the proposed SERS-based sensor to track mitochondrial function opens broad perspectives in cell bioenergetics.


Asunto(s)
Citocromos c , Hemo , Citocromos c/metabolismo , Hemo/metabolismo , Potencial de la Membrana Mitocondrial , Mitocondrias/metabolismo , Adenosina Trifosfato/metabolismo
7.
Biosensors (Basel) ; 12(1)2022 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-35049660

RESUMEN

Surface-enhanced Raman spectroscopy (SERS) is a promising tool that can be used in the detection of molecular changes triggered by disease development. Cardiovascular diseases (CVDs) are caused by multiple pathologies originating at the cellular level. The identification of these deteriorations can provide a better understanding of CVD mechanisms, and the monitoring of the identified molecular changes can be employed in the development of novel biosensor tools for early diagnostics. We applied plasmonic SERS nanosensors to assess changes in the properties of erythrocytes under normotensive and hypertensive conditions in the animal model. We found that spontaneous hypertension in rats leads (i) to a decrease in the erythrocyte plasma membrane fluidity and (ii) to a decrease in the mobility of the heme of the membrane-bound hemoglobin. We identified SERS parameters that can be used to detect pathological changes in the plasma membrane and submembrane region of erythrocytes.


Asunto(s)
Técnicas Biosensibles , Hipertensión , Animales , Eritrocitos/química , Eritrocitos/metabolismo , Hemoglobinas/química , Hemoglobinas/metabolismo , Hipertensión/sangre , Hipertensión/diagnóstico , Ratas , Espectrometría Raman
8.
Biology (Basel) ; 10(8)2021 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-34439940

RESUMEN

Brain state varies from moment to moment. While brain state can be defined by ongoing neuronal population activity, such as neuronal oscillations, this is tightly coupled with certain behavioural or vigilant states. In recent decades, abnormalities in brain state have been recognised as biomarkers of various brain diseases and disorders. Intriguingly, accumulating evidence also demonstrates mutual interactions between brain states and disease pathologies: while abnormalities in brain state arise during disease progression, manipulations of brain state can modify disease pathology, suggesting a therapeutic potential. In this review, by focusing on Alzheimer's disease (AD), the most common form of dementia, we provide an overview of how brain states change in AD patients and mouse models, and how controlling brain states can modify AD pathology. Specifically, we summarise the relationship between AD and changes in gamma and slow oscillations. As pathological changes in these oscillations correlate with AD pathology, manipulations of either gamma or slow oscillations can modify AD pathology in mouse models. We argue that neuromodulation approaches to target brain states are a promising non-pharmacological intervention for neurodegenerative diseases.

9.
Oncologist ; 26(5): 364-e734, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33749049

RESUMEN

LESSONS LEARNED: Melatonin did not increase the efficacy of systemic chemotherapy in melanoma. Metformin did not increase the efficacy of systemic chemotherapy in melanoma. BACKGROUND: Current data support the possibility of antitumor activity of melatonin and metformin. METHODS: From March 2014 to December 2016, 57 patients with disseminated melanoma received dacarbazine (DTIC) 1,000 mg/m2 on day 1 of a 28-day cycle, either as monotherapy (first group) or in combination with melatonin 3 mg p.o. daily (second group) or metformin 850 mg two times a day p.o. daily (third group) as the first-line of chemotherapy. The primary endpoint was objective response rate (ORR). Secondary endpoints were time to progression (TTP), overall survival (OS), immunologic biomarkers, and quality of life. RESULTS: ORR was 7% and did not differ among the treatment groups. Median TTP was 57, 57, and 47 days, respectively, in the first, second, and third groups (р = .362). Median OS was 236, 422, and 419 days, respectively (p = .712). Two patients from the combinations groups showed delayed response to therapy. The increase of CD3+ CD4+ HLA-DR+ lymphocytes (p = .003), CD3+ CD8+ HLA-DR+ (p = .045), CD3+ CD8+ lymphocytes (p = .012), CD4+ CD25high CD127low lymphocytes (p = .029), and overall quantity of lymphocytes (p = .021) was observed in patients with clinical benefit. CONCLUSION: No benefit was found in either combination over DTIC monotherapy. Delayed responses in melatonin and metformin combination groups were registered. The increase of lymphocyte subpopulations responsible for antitumor immune response demonstrates the immune system's potential involvement in clinical activity.


Asunto(s)
Melanoma , Melatonina , Metformina , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Dacarbazina/uso terapéutico , Humanos , Melanoma/tratamiento farmacológico , Melatonina/farmacología , Melatonina/uso terapéutico , Metformina/farmacología , Metformina/uso terapéutico , Calidad de Vida
10.
Front Chem ; 8: 550625, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33240840

RESUMEN

Widely spread crystal lattices of perovskites represent a natural flexible platform for chemical design of various advanced functional materials with unique features. An interplay between chemical bonding, defects and crystallochemical peculiarities makes the perovskite structure a "LEGO designer" utilizing natural features of chemical elements of the renowned Mendeleev's Periodic Table (PTE) celebrating its 150-year anniversary. In this mini-review, crystal chemistry and bonding features, physical and functional properties, preparation methods and tuning functional properties with periodicity "tools" of the PTE will be exemplified for legendary families of high-temperature superconductive cuprates, colossal magnetoresistive manganites and hybrid lead halides for a new generation of solar cells.

11.
Ecol Evol ; 10(20): 11591-11606, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33144986

RESUMEN

Functional traits are becoming more common in the analysis of marine zooplankton community dynamics associated with environmental change. We used zooplankton groups with common functional properties to assess long-term trends in the zooplankton caused by certain environmental conditions in a highly eutrophicated gulf.Time series of zooplankton traits have been collected since the 1960s in the Gulf of Riga, Baltic Sea, and were analyzed using a combination of multivariate methods (principal coordinate analysis) and generalized additive models.One of the most significant changes was the considerable increase in the amount of the zooplankton functional groups (FGR) in coastal springtime communities, and dominance shifts from more complex to simpler organism groups-cladocerans and rotifers.The results also show that functional trait organism complexity (body size) decreased considerably due to cladoceran and rotifer increase following elevated water temperature. Salinity and oxygen had negligible effects on the zooplankton community.

12.
J Cardiovasc Dev Dis ; 7(2)2020 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-32423031

RESUMEN

Russian patients with familial hypercholesterolemia (FH) were screened for pathogenic mutations using targeted next generation sequencing. Genetic testing was performed in 52 probands with definite or probable FH based on the Dutch lipid clinic network criteria (DLCN score ≥6). Blood samples were studied by massive parallel sequencing (Illumina HiSeq 1500 platform) using a custom capture library related to dyslipidemia and premature atherosclerosis. Mutations considered to be responsible for monogenic FH were identified in 48% of the probands: 24 with mutations in the LDLR gene and two with a mutation in the APOB gene. There were 22 pathogenic/likely pathogenic mutations in LDLR, eight of which have not been previously described in the literature. Four patients with a clinical picture of homozygous FH had two heterozygous LDLR mutations. Although mutation-negative patients had highly elevated total cholesterol and low-density lipoprotein cholesterol levels, only half of them had a family history of hypercholesterolemia. With respect to heterozygous FH, mutation-positive patients had higher maximum total cholesterol levels (p = 0.01), more severe carotid atherosclerotic lesions, and a higher percentage of premature peripheral artery disease (p = 0.03) than mutation-negative ones. However, the number of patients who suffered from myocardial infarction was similar between the two groups.

13.
Oncologist ; 25(9): e1303-e1317, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32240562

RESUMEN

LESSONS LEARNED: This study showed that carefully selected patients with locally advanced and metastatic forms of malignant melanoma and renal cell carcinoma could potentially have long-term disease control with a tag-7 gene-modified tumor cells-based vaccine. Randomized clinical trials in patients whose tumors produce low amounts of immunosuppressive factors are needed to confirm this hypothesis in both the adjuvant and metastatic settings. BACKGROUND: Immunotherapy may produce long-lasting effects on survival and toxicity. The magnitude of efficacy may be dependent on immune factors. We analyzed the results of a phase I/II study of a tag-7 gene-modified tumor cells-based vaccine (GMV) in patients with malignant melanoma (MM) or renal cell carcinoma (RCC) with biomarker analysis of immunosuppressive factors (ISFs) production by their tumor cells. METHODS: From 2001 to 2014, 80 patients received GMV: 68 with MM and 12 with RCC. Treatment in the metastatic setting included 61 patients (MM, 51; RCC, 10), and treatment in the adjuvant setting (after complete cytoreduction) included 19 patients (MM, 17; RCC, 2). Twenty-six patients were stage III (33%), and 54 (67%) were stage IV. The patients' tumor samples were transferred to culture, transfected with tag-7 gene, and inactivated by radiation. The produced product was injected subcutaneously every 3 weeks until progression or 2 years of therapy. ISFs were measured in the supernatants of the tumor cell cultures and used as predictive factors. RESULTS: No major safety issues or grade 5 adverse events (AEs) were seen. One grade 4 and two grade 3 AEs were registered. No AEs were registered in 89.4% of treatment cycles. No delayed AE was found. The 5-year overall survival (OS) in the intention-to-treat population was 25.1%. There were no differences between MM OS and RCC OS (log rank, p = .44). Median OS in the metastatic setting was 0.7 years and in the adjuvant setting was 3.1 years. Classification trees were built on the basis of ISF production (Fig. 1). The median OS was 6.6 years in the favorable prognosis (FP) group (major histocompatibility complex class I polypeptide-related sequence A [MICA] level ≤582 pg/mL, n = 15) and 4.6 months in the unfavorable (UF) group (MICA level >582 pg/mL, n = 12; p < .0001). No significant differences were found between classification trees based on ISFs (transforming growth factor ß1 [TGF-ß1], interleukin-10 [IL-10], and vascular endothelial growth factor [VEGF]). In patients with stage III-IV MM with FP, median OS was 2.3 years, with 31% patients alive at 10 years (Fig. 2) in the UF group (0.4 years; log rank, p = 1.94E-5). No FP patients received modern immunotherapy. CONCLUSION: GMV showed high results in carefully selected patients with low ISF (TGF-ß1, IL-10, and VEGF) production. The method should be further investigated in patients with FP.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Melanoma , Vacunas , Carcinoma de Células Renales/terapia , Humanos , Neoplasias Renales/terapia , Melanoma/terapia , Factor A de Crecimiento Endotelial Vascular
14.
Cancer Immunol Immunother ; 69(6): 983-988, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32078017

RESUMEN

BACKGROUND: Hepatitis C virus (HCV) interferes with activation of innate and adaptive immune responses. Theoretically, the efficacy and toxicity of immune checkpoint inhibitors in cancer patients infected with HCV may differ. Nevertheless, HCV was an exclusion criterion in most checkpoint inhibitor trials. We evaluated the efficacy and safety of nivolumab in metastatic renal cell carcinoma (mRCC) patients with or without chronic HCV infection. METHODS: In a matched cohort study, data were collected from 174 patients, retrospectively. All patients had clear-cell mRCC, chronic HCV infection (case study group), no evidence of other malignancy or cirrhosis, and had received nivolumab (3 mg/kg every 2 weeks) until disease progression or unacceptable toxicity. Quantitation of HCV RNA in plasma samples was performed before and during treatment with nivolumab with the automated HCV test (Hoffmann-La Roche, Switzerland). The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and rate of grade 3-4 adverse events in study and control cohorts. RESULTS: A total of 44 matched patients were included. Groups were well balanced. HCV-infected patients had significantly longer OS and PFS. Median OS was 27.5 (95% CI 25.3-29.7) and 21.7 (20.3-23.1) in study and control groups, respectively (P = 0.005). Median PFS was 7.5 (5.7-9.3) and 4.9 (4-5.8) (P = 0.013). Despite no differences in ORR between groups (27% vs. 23%, P = 0.7), patients with HCV had significantly more durable responses (P = 0.01). Nivolumab was well tolerated in all HCV-positive patients. No unexpected toxicity was observed. Assessment of viral load during nivolumab therapy was available in 14 of 22 (64%) patients with HCV. Nivolumab did not significantly impact HCV concentration (mean change 210 IU/ml, P = 0.82) in the absence of antiviral therapy. CONCLUSIONS: The efficacy and safety profiles observed in this study support the administration of nivolumab in mRCC patients infected with HCV and warrant further investigation.


Asunto(s)
Antineoplásicos Inmunológicos/uso terapéutico , Carcinoma de Células Renales/tratamiento farmacológico , Hepatitis C Crónica/tratamiento farmacológico , Nivolumab/uso terapéutico , Antineoplásicos Inmunológicos/farmacología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nivolumab/farmacología , Estudios Retrospectivos
15.
Mar Environ Res ; 112(Pt B): 48-55, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26453004

RESUMEN

Intense human activities facilitate the successful spread and establishment of non-indigenous aquatic organisms in marine and freshwater ecosystems. In some cases such intrusions result in noticeable and adverse changes in the recipient environments. In the Baltic Sea, the discovery and rapid initial spread of the North American wedge clam Rangia cuneata represents a new wave of invasion which may trigger unpredictable changes of the local benthic communities. In this study we present a species-specific DNA-based marker developed in silico and experimentally tested on environmental samples. Marker specificity and sensitivity were assessed in vitro from water samples containing different mixtures of the target species and other five bivalves currently present in the region: the native Cerastoderma glaucum, Macoma balthica and Mytilus trossulus, the invasive Dreissena polymorpha and the cryptogenic Mya arenaria. Cross-species amplification was not found in any case. The method allows to detecting at least 0.4 ng of R. cuneata DNA per µl, and 0.1 g of tissue per liter of water. Finally, the marker performance was assessed in water samples from the Baltic Sea and Vistula Lagoon. The coincidence between independent visual observations of R. cuneata and positive PCR amplification of the marker from the water samples confirmed the efficiency of this highly reproducible, fast, and technically easy method. R. cuneata traces can be detected from environmental DNA even when the population is sparse and small, enabling rapid management responses and allowing to track the invasion dynamics.


Asunto(s)
Bivalvos/clasificación , Bivalvos/genética , Conservación de los Recursos Naturales/métodos , Cartilla de ADN/genética , Especies Introducidas , Reacción en Cadena de la Polimerasa , Animales , Secuencia de Bases , Bivalvos/metabolismo , Cartilla de ADN/metabolismo , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Federación de Rusia , Alineación de Secuencia , Especificidad de la Especie
16.
Sci Rep ; 5: 13793, 2015 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-26346634

RESUMEN

Selective study of the electron transport chain components in living mitochondria is essential for fundamental biophysical research and for the development of new medical diagnostic methods. However, many important details of inter- and intramembrane mitochondrial processes have remained in shadow due to the lack of non-invasive techniques. Here we suggest a novel label-free approach based on the surface-enhanced Raman spectroscopy (SERS) to monitor the redox state and conformation of cytochrome c in the electron transport chain in living mitochondria. We demonstrate that SERS spectra of living mitochondria placed on hierarchically structured silver-ring substrates provide exclusive information about cytochrome c behavior under modulation of inner mitochondrial membrane potential, proton gradient and the activity of ATP-synthetase. Mathematical simulation explains the observed enhancement of Raman scattering due to high concentration of electric near-field and large contact area between mitochondria and nanostructured surfaces.


Asunto(s)
Citocromos c/química , Citocromos c/metabolismo , Mitocondrias/metabolismo , Espectrometría Raman , Adenosina Trifosfato/biosíntesis , Animales , Transporte de Electrón , Masculino , Potencial de la Membrana Mitocondrial , Mitocondrias Cardíacas/metabolismo , Protones , Ratas , Espectrometría Raman/métodos
17.
Inorg Chem ; 52(20): 11703-10, 2013 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-24083336

RESUMEN

A new perovskite, CaCo(2+)3V(4+)4O12, has been synthesized at high-pressure and high-temperature (HP-HT) conditions. The properties of this perovskite were examined by a range of techniques. CaCo3V4O12 was found to adopt a double-perovskite cubic lattice [a = 7.3428(6) Å] with Im3 symmetry. We have established that this new perovskite is stable at ambient conditions, and its oxidation and/or decomposition at ambient pressure begins above 500 °C. It undergoes an abrupt antiferromagnetic transition around 98 K. Electrical resistivity data suggest semimetallic conductivity in the temperature range of 1.6-370 K. We have established that the Co(2+) ions in CaCo3V4O12 are in the high-spin state with a sizable orbital moment, even though their square-planar oxygen coordination could be more suitable for the low-spin state, which is prone to Jahn-Teller distortion. Electrical resistivity curves also exhibit a distinct steplike feature around 100 K. CaCo3V4O12 is a first example of perovskite in which the sites A' are fully occupied by Co(2+) ions, and hence its synthesis opens the door to a new class of double perovskites, ACo3B4O12, that may be derived by chemical substitution of the A sublattice by lanthanides, sodium, strontium, and bismuth and by other elements and/or of the B sublattice by some other transition metals.

18.
Proc Natl Acad Sci U S A ; 108(25): 10098-103, 2011 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-21646539

RESUMEN

Prokaryotic clustered regularly interspaced short palindromic repeat (CRISPR)/Cas (CRISPR-associated sequences) systems provide adaptive immunity against viruses when a spacer sequence of small CRISPR RNA (crRNA) matches a protospacer sequence in the viral genome. Viruses that escape CRISPR/Cas resistance carry point mutations in protospacers, though not all protospacer mutations lead to escape. Here, we show that in the case of Escherichia coli subtype CRISPR/Cas system, the requirements for crRNA matching are strict only for a seven-nucleotide seed region of a protospacer immediately following the essential protospacer-adjacent motif. Mutations in the seed region abolish CRISPR/Cas mediated immunity by reducing the binding affinity of the crRNA-guided Cascade complex to protospacer DNA. We propose that the crRNA seed sequence plays a role in the initial scanning of invader DNA for a match, before base pairing of the full-length spacer occurs, which may enhance the protospacer locating efficiency of the E. coli Cascade complex. In agreement with this proposal, single or multiple mutations within the protospacer but outside the seed region do not lead to escape. The relaxed specificity of the CRISPR/Cas system limits escape possibilities and allows a single crRNA to effectively target numerous related viruses.


Asunto(s)
Secuencia de Bases , ARN/genética , ARN/metabolismo , ADN Viral/genética , ADN Viral/inmunología , Escherichia coli/genética , Escherichia coli/inmunología , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Secuencias Invertidas Repetidas , Sustancias Macromoleculares/química , Sustancias Macromoleculares/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Virus/genética , Virus/inmunología
19.
Acta Cardiol ; 64(3): 405-9, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19593954

RESUMEN

OBJECTIVE: The aim of our investigation was to assess the influence of rosuvastatin therapy and myocardial revascularization on angiogenic growth factors in coronary artery disease patients. METHODS AND RESULTS: Two main groups were examined: group one consisted of patients with successful percutaneous coronary intervention and group two consisted of patients 3 months on rosuvastatin therapy.Vascular endothelial growth factor (VEGF), VEGF receptor Flt-1 (sVEGF-R1) and transforming growth factor beta-1 (TGF-beta1) levels were measured in healthy volunteers and CAD patients before and 6 days after myocardial revascularization.VEGF and basic fibroblast growth factor (bFGF) levels were measured before and 3 months after rosuvastatin therapy, as well as total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), C-reactive protein (CRP), interleukin 6 (IL-6) and endothelium-dependent vasodilation. VEGF levels did not differ, but beta-TGF levels were significantly lower in CAD patients in comparison with healthy subjects, P < 0.0001. Myocardial revascularization caused changes of VEGF levels from 192.4 +/- 166.1 pg/ml to 264.7 +/- 226.6 pg/ml (P = 0.0066). There were positive changes in lipid levels, lowering of CRP and IL-6 concentrations, improving of endothelial function and decreasing of VEGF levels from 382 +/- 249 pg/ml to 297 +/- 220 pg/ml (P = 0.006) 3 months after rosuvastatin treatment. CONCLUSIONS: There is an elevation of VEGF levels early after myocardial revascularization that may reflect a transient ischaemia and potentially may provoke atherosclerotic plaque neovascularization. Rosuvastatin leads to a decrease of VEGF levels that can be a reflection of the influence on endogenous angiogenesis. There was no correlation between inflammatory factors and VEGF that gives a suggestion about an absence of direct CRP and IL-6 impact on VEGF decreasing during statin treatment.


Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Fluorobencenos/uso terapéutico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Revascularización Miocárdica , Pirimidinas/uso terapéutico , Sulfonamidas/uso terapéutico , Proteína C-Reactiva/efectos de los fármacos , Proteína C-Reactiva/metabolismo , Enfermedad de la Arteria Coronaria/sangre , Enfermedad de la Arteria Coronaria/terapia , Femenino , Factor 2 de Crecimiento de Fibroblastos/sangre , Factor 2 de Crecimiento de Fibroblastos/efectos de los fármacos , Humanos , Inflamación/sangre , Interleucina-6/sangre , Masculino , Persona de Mediana Edad , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Rosuvastatina Cálcica , Factor de Crecimiento Transformador beta1/sangre , Factor de Crecimiento Transformador beta1/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/sangre , Factor A de Crecimiento Endotelial Vascular/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...