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1.
Behav Sci (Basel) ; 14(5)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38785854

RESUMEN

Traumatic experiences are associated with increased experiences of positive schizotypy. This may be especially important for People of Color, who experience higher rates of trauma and racial discrimination. No study to date has examined how racial disparities in traumatic experiences may impact schizotypy. Furthermore, of the studies that have examined the relationship between trauma and schizotypy, none have examined racial discrimination as a potential moderator. The present study examined if racial discrimination moderates the relationship between trauma and multidimensional (positive, negative, and disorganized) schizotypy. In a sample of 770 college students, we conducted chi-squared analyses, analyses of variance, and stepwise regressions. We found that Black students experienced significantly higher racial discrimination and trauma than Latinx and Asian students. Furthermore, Black and Latinx students experienced significantly more multidimensional schizotypy items than Asian students. Trauma and racial discrimination explained 8 to 23% of the variance in each dimension of schizotypy. Racial discrimination did not moderate the relationships between trauma and multidimensional schizotypy. Our findings suggest that we need to examine risk factors that may prevent recovery from psychotic disorders. Additionally, disorganized schizotypy showed the most robust associations and may be a critical site of intervention.

2.
Schizophr Res ; 266: 227-233, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38428120

RESUMEN

Given the culturally diverse landscape of mental healthcare and research, ensuring that our psychological constructs are measured equivalently across diverse populations is critical. One construct for which there is significant potential for inequitable assessment is paranoia, a prominent feature in psychotic disorders that can also be driven by culture and racial marginalization. This study examined measurement invariance-an analytic technique to rigorously investigate whether a given construct is being measured similarly across groups-of the Revised-Green Paranoid Thought Scale (R-GPTS; Freeman et al., 2021) across Black and White Americans in the general population. Racial group differences in self-reported paranoia were also examined. The analytic sample consisted of 480 non-Hispanic White and 459 non-Hispanic Black Americans. Analyses demonstrated full invariance (i.e., configural, metric, and scalar invariance) of the R-GPTS across groups, indicating that the R-GPTS appropriately captures self-reported paranoia between Black and White Americans. Accordingly, it is reasonable to compare group endorsement: Black participants endorsed significantly higher scores on both the ideas of reference and ideas of persecution subscales of the R-GPTS (Mean ± SD = 10.91 ± 7.12 versus 8.21 ± 7.17 and Mean ± SD = 10.18 ± 10.03 versus 6.35 ± 8.35, for these subscales respectively). Generalized linear modeling revealed that race remained a large and statistically significant predictor of R-GPTS total score (ß = -0.38756, p < 0.001) after controlling for relevant demographic factors (e.g., sex, age). This study addresses a critical gap within the existing literature as it establishes that elevations in paranoia exhibited by Black Americans in the R-GPTS reflect actual differences between groups rather than measurement artifacts.


Asunto(s)
Negro o Afroamericano , Trastornos Psicóticos , Humanos , Etnicidad , Trastornos Paranoides/psicología , Psicometría , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Encuestas y Cuestionarios , Blanco
3.
JMIR Form Res ; 7: e49998, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37792468

RESUMEN

BACKGROUND: Demand for adolescent mental health services has surged in the aftermath of the COVID-19 pandemic, and traditional models of care entailing in-person services with licensed mental health providers are inadequate to meet demand. However, research has shown that with proper training and supervision mentors can work with youth with mental health challenges like depression and anxiety and can even support the use of evidence-based strategies like cognitive behavioral therapy (CBT). In our increasingly connected world, youth mentors can meet with young people on a web-based platform at their convenience, reducing barriers to care. Moreover, the internet has made evidence-based CBT skills for addressing depression and anxiety more accessible than ever. As such, when trained and supervised by licensed clinicians, mentors are an untapped resource to support youth with mental health challenges. OBJECTIVE: The objective of this study was to develop and assess the feasibility and acceptability of Appa Health (Appa), an evidence-based mental health mentoring program for youth experiencing symptoms of depression and anxiety. This paper describes the development, pilot testing process, and preliminary quantitative and qualitative outcomes of Appa's 12-week smartphone app program which combines web-based near-peer mentorship with short-form TikTok-style videos teaching CBT skills created by licensed mental health professionals who are also social media influencers. METHODS: The development and testing processes were executed through collaboration with key stakeholders, including young people and clinical and research advisory boards. In the pilot study, young people were assessed for symptoms of depression or anxiety using standard self-report clinical measures: the Patient Health Questionnaire-8 and the Generalized Anxiety Disorder-7 scales. Teenagers endorsing symptoms of depression or anxiety (n=14) were paired with a mentor (n=10) based on preferred characteristics such as gender, race or ethnicity, and lesbian, gay, bisexual, transgender, queer (LGBTQ) status. Quantitative survey data about the teenagers' characteristics, mental health, and feasibility and acceptability were combined with qualitative data assessing youth perspectives on the program, their mentors, and the CBT content. RESULTS: Participants reported finding Appa helpful, with 100% (n=14) of teenagers expressing that they felt better after the 12-week program. Over 85% (n=12) said they would strongly recommend the program to a friend. The teenagers were engaged, video chatting with mentors consistently over the 12 weeks. Metrics of anxiety and depressive symptoms reduced consistently from week 1 to week 12, supporting qualitative data suggesting that mentoring combined with CBT strategies has the potential to positively impact youth mental health and warrants further study. CONCLUSIONS: Appa Health is a novel smartphone app aiming to improve the well-being of youth and reduce anxiety and depressive symptoms through web-based mentoring and engaging CBT video content. This formative research sets the stage for a large-scale randomized controlled trial recently funded by the National Institutes of Health Small Business Innovation Research program.

4.
Schizophr Res ; 253: 30-39, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-34895794

RESUMEN

There is a dearth of research examining how individual-level and systemic racism may lead to elevated diagnostic and symptom rates of paranoia in Black Americans. The present study employed item response theory methods to investigate item- and subscale-level functioning in the Schizotypal Personality Questionnaire (SPQ) in 388 Black and 450 White participants across the schizophrenia-spectrum (i.e., non-psychiatric controls, individuals with schizophrenia, schizoaffective disorder, or schizotypal personality disorder). It was predicted that (1) Black participants would score significantly higher than Whites on the Suspiciousness and Paranoid Ideation subscale of the SPQ, while controlling for total SPQ severity and relevant demographics and (2) Black participants would endorse these subscale items at a lower latent severity level (i.e., total SPQ score) compared to Whites. Generalized linear modeling showed that Black participants endorsed higher scores on subscales sampling paranoia (e.g., Suspiciousness and Paranoid Ideation), while White participants endorsed higher rates within disorganized/positive symptomatology subscales (e.g., Odd or Eccentric Behavior). IRT analyses showed that Black individuals also endorse items within the Suspiciousness and Paranoid Ideation subscale at lower latent severity levels, leading to inflated subscale scores when compared to their White counterparts. Results indicate prominent race effects on self-reported paranoia as assessed by the SPQ. This study provides foundational data to parse what could be normative endorsements of paranoia versus indicators of clinical risk in Black Americans. Implications and recommendations for paranoia research and assessment are discussed.


Asunto(s)
Trastornos Psicóticos , Trastorno de la Personalidad Esquizotípica , Humanos , Autoinforme , Trastornos Paranoides/diagnóstico , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Trastorno de la Personalidad Esquizotípica/psicología , Encuestas y Cuestionarios , Personalidad
5.
Environ Monit Assess ; 192(11): 706, 2020 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-33064217

RESUMEN

Recently, cyanobacteria blooms have become a concern for agricultural irrigation water quality. Numerous studies have shown that cyanotoxins from these harmful algal blooms (HABs) can be transported to and assimilated into crops when present in irrigation waters. Phycocyanin is a pigment known only to occur in cyanobacteria and is often used to indicate cyanobacteria presence in waters. The objective of this work was to identify the most influential environmental covariates affecting the phycocyanin concentrations in agricultural irrigation ponds that experience cyanobacteria blooms of the potentially toxigenic species Microcystis and Aphanizomenon using machine learning methodology. The study was performed at two agricultural irrigation ponds over a 5-month period in the summer of 2018. Phycocyanin concentrations, along with sensor-based and fluorometer-based water quality parameters including turbidity (NTU), pH, dissolved oxygen (DO), fluorescent dissolved organic matter (fDOM), conductivity, chlorophyll, color dissolved organic matter (CDOM), and extracted chlorophyll were measured. Regression tree analyses were used to determine the most influential water quality parameters on phycocyanin concentrations. Nearshore sampling locations had higher phycocyanin concentrations than interior sampling locations and "zones" of consistently higher concentrations of phycocyanin were found in both ponds. The regression tree analyses indicated extracted chlorophyll, CDOM, and NTU were the three most influential parameters on phycocyanin concentrations. This study indicates that sensor-based and fluorometer-based water quality parameters could be useful to identify spatial patterns of phycocyanin concentrations and therefore, cyanobacteria blooms, in agricultural irrigation ponds and potentially other water bodies.


Asunto(s)
Ficocianina , Estanques , Riego Agrícola , Monitoreo del Ambiente , Maryland
6.
Phys Biol ; 11(4): 045003, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25076006

RESUMEN

The objective of the studies described here was the development of a mathematical model which would fit experimental data for the repair of single and double strand breaks induced in DNA in living cells by exposure to ionizing radiation, and which would allow to better understand the processes of DNA repair. DNA breaks are believed to play the major role in radiation-induced lethality and formation of chromosome deletions, and are therefore crucial to the response of cells to radiotherapy. In an initial model which we reported on the basis of data for the repair of Epstein-Barr minichromosomes in irradiated Raji cells, we assumed that DNA breaks are induced only at the moment of irradiation and are later removed by repair systems. This work gives a development of that mathematical model which fits the experimental results more precisely and suggests strongly that DNA breaks are generated not only by direct irradiation but also later, probably by systems engaged in repair of oxidative damage.


Asunto(s)
Daño del ADN/efectos de la radiación , Reparación del ADN , ADN Viral/efectos de la radiación , Rayos gamma/efectos adversos , Herpesvirus Humano 4/efectos de la radiación , Modelos Teóricos , Línea Celular Tumoral , ADN Viral/genética , Herpesvirus Humano 4/genética , Humanos
7.
Phys Rev Lett ; 110(11): 117206, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-25166573

RESUMEN

We discover that hcp phases of Fe and Fe(0.9)Ni(0.1) undergo an electronic topological transition at pressures of about 40 GPa. This topological change of the Fermi surface manifests itself through anomalous behavior of the Debye sound velocity, c/a lattice parameter ratio, and Mössbauer center shift observed in our experiments. First-principles simulations within the dynamic mean field approach demonstrate that the transition is induced by many-electron effects. It is absent in one-electron calculations and represents a clear signature of correlation effects in hcp Fe.

8.
J Appl Genet ; 51(3): 343-52, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20720310

RESUMEN

Single-nucleotide polymorphisms in genes involved in DNA-damage-induced responses are reported frequently to be a risk factor in various cancer types. Here we analysed polymorphisms in 5 genes involved in DNA repair (XPD Asp312Asn and Lys751Gln, XRCC1 Arg399Gln, APE1 Asp148Glu, NBS1 Glu185Gln, and XPA G-4A) and in a gene involved in regulation of the cell-cycle (CCND1 A870G). We compared their frequencies in groups of colon, head and neck, and breast cancer patients, and 2 healthy control groups: (1) matched healthy Polish individuals and (2) a NCBI database control group. Highly significant differences in the distribution of genotypes of the APE1, XRCC1 and CCND1 genes were found between colon cancer patients and healthy individuals. The 148Asp APE1 allele and the 399Gln XRCC1 allele apparently increased the risk of colon cancer (OR = 1.9-2.3 and OR = 1.5-2.1, respectively). Additionally, frequencies of XPD genotypes differed between healthy controls and patients with colon or head and neck cancer. Importantly, no differences in the distribution of these polymorphisms were found between healthy controls and breast cancer patients. The data clearly indicate that the risk of colon cancer is associated with single-nucleotide polymorphism in genes involved in base-excision repair and DNA-damage-induced responses.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias del Colon/genética , Daño del ADN/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Neoplasias de Cabeza y Cuello/genética , Polimorfismo de Nucleótido Simple/genética , Alelos , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes/genética , Humanos , Polonia
9.
Ukr Biokhim Zh (1999) ; 81(4): 48-58, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20387634

RESUMEN

Glutathione S-transferase P1 is a major phase II detoxification enzyme in most cell types. Aberrant expression of GSTP1 is associated with carcinogenesis and development of multidrug resistance. GSTP1 gene transcription is regulated by promoter methylation and by transcription factors. To elucidate the mechanisms responsible for the different levels of GSTP1 expression observed in Hbl-100 and BeWo cells we utilized truncated promoter constructs to compare the functional role of different promoter elements. We also identified transcription factors binding the responsive elements by electrophoretic mobility shift assay. The applied approaches provided the evidence that binding of transcription factors to ARE, CRE and NF-kappaB sites are responsible for the cell specific levels of GSTP1 expression in Hbl-100 and BeWo cells. It was also indicated that partial promoter methylation occurs in BeWo cells.


Asunto(s)
Neoplasias de la Mama/genética , Coriocarcinoma/genética , Regulación Enzimológica de la Expresión Génica , Gutatión-S-Transferasa pi/genética , Transcripción Genética , Neoplasias Uterinas/genética , Western Blotting , Línea Celular Tumoral , Metilación de ADN , Ensayo de Cambio de Movilidad Electroforética , Femenino , Humanos , Reacción en Cadena de la Polimerasa , Embarazo , Regiones Promotoras Genéticas , Unión Proteica , Factores de Transcripción/metabolismo
10.
Int J Radiat Biol ; 84(8): 635-42, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18608641

RESUMEN

PURPOSE: To study the relationship between lymphocyte radiosensitivity measured in vitro and acute reactions to radiotherapy in patients with head and neck cancer. MATERIALS AND METHODS: Acute reactions were measured in 34 patients using the Dische scale. Lymphocyte radiosensitivity was measured using the alkaline comet assay, the micronucleus assay, the nuclear division index and morphological assessment of apoptosis. RESULTS: There was a weak, statistically significant correlation between in vitro radiosensitivity measured as the rate of DNA damage repair and the cumulative radiation dose exerting the maximum acute reaction scored (r = -0.366, p = 0.039, n = 34). Subgroup analyses showed that for patients with a low level of radiation-induced DNA damage there was a statistically significant relationship between lymphocyte radiosensitivity measured as inhibition of proliferation and acute toxicity (r = -0.621, p = 0.007, n = 18). For patients with a high level of residual DNA damage, there was a relationship between lymphocyte radiosensitivity measured using the micronucleus assay and acute toxicity (r = -0.597, p = 0.023, n = 14). CONCLUSIONS: Combining two measures of radiosensitivity improves the ability to correlate in vitro lymphocyte radiosensitivity and acute radiotherapy toxicity data.


Asunto(s)
Daño del ADN/efectos de la radiación , Reparación del ADN/efectos de la radiación , Neoplasias de Cabeza y Cuello/radioterapia , Linfocitos/efectos de la radiación , Ensayo Cometa , Roturas del ADN de Cadena Simple/efectos de la radiación , Neoplasias de Cabeza y Cuello/genética , Humanos , Linfocitos/ultraestructura , Pruebas de Micronúcleos , Tolerancia a Radiación , Radioterapia/efectos adversos
11.
Ukr Biokhim Zh (1999) ; 79(4): 67-75, 2007.
Artículo en Ucraniano | MEDLINE | ID: mdl-18219993

RESUMEN

Glutathione S-transferase P1-1 is the main phase II xenobiotic metabolism enzyme in human placenta. Low level of its gene expression and corresponding ineffective protection of fetus from toxic compounds is associated with pregnancy disorders such as preeclampsia and abnormalities of fetus development. It was previously reported that environmental radioactive contamination caused down-regulation of GSTP1 transcription in human placenta, but mechanisms responsible for such changes were unclear. In the present study we have found that observed changes in transcription of this gene are not caused by promoter methylation because GSTP1 promoter was not methylated in any of analyzed 91 placental samples. Regulation of GSTP1 by methylation or transcription factors was not previously studied in human placenta. Using "Gene Expression Atlas" online software the placental expression profile of transcription factors known to interact with GSTP1 promoter in other cell types, was identified. According to computer analysis the genes coding for GATA2, GATA3, Fos-B, Nrf3 and MafK transcription factors are highly expressed in human placenta, while genes coding for c-Fos, Juns, Mafs, ERbeta, RARalpha and NF-kappaB factors have moderate level of expression. Competitive EMSA provided the evidence that ARE and NF-kappaB-like sites specifically interacted with placental nuclear proteins. Among these proteins transcription factors AP-1 and NF-kappaB were identified using corresponding consensus oligonucleotides as competitors in EMSA.


Asunto(s)
Regulación Enzimológica de la Expresión Génica , Gutatión-S-Transferasa pi/genética , Placenta/enzimología , Transcripción Genética , Femenino , Humanos , Metilación , Regiones Promotoras Genéticas , Factores de Transcripción/genética
12.
Biochemistry (Mosc) ; 68(7): 810-5, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12946264

RESUMEN

The structural and functional organization of the adaptor protein Ruk(1) is characterized by the presence of three SH3-domains at the N-terminus followed by Pro- and Ser-rich sequences and a C-terminal coiled-coil region. Multiple modules in the Ruk(1) structure involved in protein-protein interactions can provide for formation of ligand clusters with varied properties and subcellular location. To study the nature and biological role of such complexes, the recombinant protein Ruk(1) with a Glu-epitope at the C-terminus (Ruk(1) Glu-tagged) was purified from transfected HEK293 cells by affinity chromatography on protein G-Sepharose with covalently conjugated anti-Glu-tag antibodies. By SDS polyacrylamide gel electrophoresis with subsequent staining with silver, a set of minor bands in addition to the 85-kD Ruk(1) Glu-tagged was detected in the purified preparation of the recombinant protein. Proteins with affinity for nucleic acids were also revealed in the Ruk(1) Glu-tagged preparation by retardation of electrophoretic mobility of 32P-labeled oligodeoxyribonucleotides in gel. The Ruk(1) Glu-tagged preparation was also shown to hydrolyze both deoxyribonucleotides and plasmid DNA. ZnCl2 and heparin inhibited the DNAse activity. These findings suggest the presence of DNases associated with the Ruk(1) protein in HEK293 cells. Such complexes were isolated from lysates of HEK293 cells by chromatography on heparin-Sepharose. By elution with 0.5 and 1.0 M NaCl, two fractions with DNase activity and containing proteins with molecular weights of 83, 80, and 72 kD were obtained. The reaction was inhibited by ZnCl2 and heparin, and previous precipitation of Ruk-related proteins with anti-Ruk antibodies resulted in the exhaustion of nuclease activity. By immunoblotting with anti-Ruk antibodies, 83-kD protein immunologically related to the Ruk(1) protein was identified in the fractions. It was concluded that the adaptor protein Ruk(1) forms complexes with endonucleases in HEK293 cells.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Desoxirribonucleasas/metabolismo , Proteínas Adaptadoras del Transporte Vesicular/genética , Proteínas Adaptadoras del Transporte Vesicular/aislamiento & purificación , Proteínas Portadoras/genética , Proteínas Portadoras/aislamiento & purificación , Proteínas Portadoras/metabolismo , Línea Celular , ADN/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/aislamiento & purificación , Proteínas de Unión al ADN/metabolismo , Desoxirribonucleasas/genética , Desoxirribonucleasas/aislamiento & purificación , Humanos , Unión Proteica , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/aislamiento & purificación , Proteínas Recombinantes de Fusión/metabolismo , Transfección
13.
Mutat Res ; 491(1-2): 1-7, 2001 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-11287291

RESUMEN

The protective effect of Vitamins C, E and beta-carotene against gamma-ray-induced DNA damage in human lymphocytes in vitro was investigated. Cultured lymphocytes were exposed to increasing concentration of these vitamins either before or after irradiation with 2Gy of gamma-rays and DNA damage was estimated using micronucleus assay. A radioprotective effect was observed when antioxidant vitamins were added to cultured cells before as well after irradiation; the strongest effect was observed when they were added no later than 1h after irradiation. The radioprotective effect of vitamins also depended on their concentration; Vitamins C added at low concentration (1 microg/ml) before exposure of the cells to radiation prevented induction of micronuclei. Vitamin E at the concentration above 2 microg/ml decreased the level of radiation-induced micronuclei when compared to the cells irradiated without vitamin treatment. beta-Carotene was effective at all tested concentrations from 1 to 5 microg/ml and reduced the number of micronuclei in irradiated cells. The vitamins had no effect on radiation-induced cytotoxicity as measured by nuclear division index. The radioprotective action of antioxidant Vitamins C, E and beta-carotene was dependent upon their concentration as well as time and sequence of application.


Asunto(s)
Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Daño del ADN/efectos de los fármacos , Linfocitos/efectos de los fármacos , Vitamina E/farmacología , beta Caroteno/farmacología , Rayos gamma , Humanos , Técnicas In Vitro , Linfocitos/efectos de la radiación , Linfocitos/ultraestructura , Pruebas de Micronúcleos , Protectores contra Radiación/farmacología
14.
Inorg Chem ; 40(1): 134-9, 2001 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-11195371

RESUMEN

The light-induced high-spin-->low-spin relaxation for the Fe(II) spin-crossover compounds [Fe(btpa)](PF6)2 and [Fe(b(bdpa))](PF6)2 in solution, where btpa is the potentially octadentate ligand N,N,N',N'-tetrakis(2-pyridylmethyl)-6,6'-bis(aminomethyl)-2,2'-bipyridine and b(bdpa) is the analogous hexadentate ligand N,N'-bis(benzyl)-N,N'-bis(2-pyridylmethyl)-6,6'-bis(aminomethyl)-2,2'- bipyridine, respectively, has been studied by temperature-dependent laser flash photolysis. [Fe(b(bdpa))](PF6)2 shows single-exponential 5T2-->1A1 relaxation kinetics, whereas [Fe(btpa)](PF6)2 exhibits solvent-independent biphasic relaxation kinetics. The fast process of [Fe(btpa)](PF6)2 with a rate constant, kHL, of 2.5 x 10(7) s-1 at 295 K and an activation energy, Ea, of 1294(26) cm-1 in methanol can be assigned to the 5T2-->1A1 relaxation as well. The slow process with a kHL(295 K) of 3.7 x 10(5) s-1 and a Ea of 2297(32) cm-1 in methanol--which is the slowest light-induced relaxation process observed so far for an Fe(II) spin-crossover complex in solution--is assigned to a coupling of the 5T2-->1A1 relaxation process to a geometrical rearrangement within the pendent pyridyl arms.

15.
Acta Biochim Pol ; 47(2): 443-50, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11051209

RESUMEN

Proteins recognizing and binding to damaged DNA (DDB-proteins) were analyzed in human lymphocytes obtained from healthy donors. Using an electrophoretic mobility shift assay several complexes between nuclear extract proteins and damaged DNA were detected: a complex specific for DNA damaged by N-acetoxy-N-acetylaminofluorene, another complex specific for UV-irradiated DNA, and two complexes specific for DNA damaged by cis-dichlorodiammine platinum. All the detected complexes differed in electrophoretic mobility and possibly contained different proteins. Complexes specific for free DNA ends were also detected in protein extracts from lymphocytes.


Asunto(s)
Daño del ADN , Proteínas de Unión al ADN/metabolismo , Linfocitos/metabolismo , 7,8-Dihidro-7,8-dihidroxibenzo(a)pireno 9,10-óxido/toxicidad , Acetoxiacetilaminofluoreno/toxicidad , Adulto , Secuencia de Bases , Núcleo Celular/metabolismo , Células Cultivadas , Cisplatino/toxicidad , Citoplasma/metabolismo , Proteínas de Unión al ADN/aislamiento & purificación , Humanos , Linfocitos/efectos de los fármacos , Linfocitos/efectos de la radiación , Sondas de Oligonucleótidos , Rayos Ultravioleta
16.
Acta Crystallogr A ; 56(Pt 1): 11-4, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10874411

RESUMEN

A novel approach to diffraction analysis of decorated quasicrystals is discussed. An average unit cell has been constructed for a decorated Fibonacci chain and used for analysis of its diffraction pattern. After some transformation of the scattering vectors, all the diffraction peaks are described by a single envelope function which is characteristic of a given decoration. It has been shown that by knowing several diffraction intensities, in a limited range of the scattering vector, it is possible to reconstruct the envelope function successfully and distinguish between different decorated structures.

17.
Acta Biochim Pol ; 46(1): 173-80, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10453993

RESUMEN

Proteins which bind to the DNA damaged by genotoxic agents can be detected in all living organisms. Damage-recognition proteins are thought to be generally involved in DNA repair mechanisms. On the other hand, the relevance to DNA repair of some other proteins which show elevated affinity to damaged DNA (e.g. HMG-box containing proteins or histone H1) has not been established. Using the electrophoretic mobility-shift assay we have investigated damage-recognition proteins in nuclei from rat hepatocytes. We detected two different protein complexes which preferentially bound the DNA damaged by N-acetoxy-acetylaminofluorene. One of them also recognized the DNA damaged by benzo(a)pyrene diol epoxide (yet with much lower efficiency). The proteins which bind to damaged DNA are permanently present in rat cells and their level does not change after treatment of animals with the carcinogens. Differences in the affinity of the detected damage-recognition proteins to DNA lesion evoked by either carcinogen did not correlate with more efficient removal from hepatic DNA of 2-acetylaminofluorene-induced adducts than benzo(a)pyrene-induced ones.


Asunto(s)
Acetoxiacetilaminofluoreno/toxicidad , Aductos de ADN , Proteínas de Unión al ADN/efectos de los fármacos , Animales , Secuencia de Bases , Cartilla de ADN , Reparación del ADN , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Proteínas Nucleares/efectos de los fármacos , Ratas
18.
Acta Biochim Pol ; 46(3): 777-84, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10698286

RESUMEN

We have analyzed the DNA fragment localized about 11 to 17.5 kb upstream of the chicken alpha-globin gene domain (the fragment was designed as alpha-0). The nucleotide sequence of its 3.3 kb-long 5' part was established and interactions with nuclear matrix proteins were studied. The DNA region localized about 16 kb upstream of the embryonic pi-globin gene showed high affinity to nuclear matrices in vitro. Two palindromes and a cluster of inverted repeats were co-localized in the same region. The whole 6.6 kb alpha-0 fragment decreased the activity of linked CAT reporter gene when transfected into chicken erythroblastoid cells.


Asunto(s)
ADN/genética , Globinas/genética , Animales , Secuencia de Bases , Línea Celular , Embrión de Pollo , Cloranfenicol O-Acetiltransferasa/genética , ADN/metabolismo , Eritroblastos/metabolismo , Genes Reporteros , Matriz Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Unión Proteica , Secuencias Repetitivas de Ácidos Nucleicos , Transfección
19.
Mutat Res ; 417(2-3): 85-94, 1998 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-9733928

RESUMEN

The modifying effect of treatment with vitamins C, E and beta-carotene on the clastogenic activity of gamma rays was investigated in mice. Damage in vivo was measured by the micronucleus assay in bone marrow polychromatic erythrocytes and exfoliated bladder cells. The vitamins were administered orally, either for five consecutive days before or immediately after irradiation with 2 Gy of gamma rays. The results show that pretreatment with vitamin E (100-200 mg/kg/day) and beta-carotene (3-12 mg/kg/day) were effective in protecting against micronucleus induction by gamma rays. Vitamin C depending on its concentration enhanced the radiation effect (400 mg/kg/day), or reduced the number of micronucleated polychromatic erythrocytes (50-100 mg/kg/day). Such effect was weekly observed in exfoliated bladder cells. The most effective protection in both tissues was noted when a mixture of these vitamins was used as a pretreatment. Administration of the all antioxidant vitamins to mice immediately after irradiation was also effective in reducing the radiation-induced micronucleus frequency. The data from the in vitro experiments based on the comet assay show that the presence of the vitamins in culture medium influences the kinetic of repair of radiation-induced DNA damage in mouse leukocytes.


Asunto(s)
Antioxidantes/uso terapéutico , Ácido Ascórbico/uso terapéutico , Daño del ADN/efectos de los fármacos , Vitamina E/uso terapéutico , beta Caroteno/uso terapéutico , Animales , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/efectos de la radiación , Células Cultivadas , Rayos gamma/efectos adversos , Masculino , Ratones , Ratones Endogámicos C57BL , Pruebas de Mutagenicidad , Traumatismos Experimentales por Radiación/prevención & control , Traumatismos Experimentales por Radiación/terapia , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/efectos de la radiación
20.
Cancer Lett ; 108(2): 215-23, 1996 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-8973598

RESUMEN

The formation of UV-induced photoproducts in the chromatin fractions of human lymphocytes was studied by 32P-post-labeling. A higher level of DNA lesions was found in the matrix-attached DNA fraction as compared to non-matrix DNA of irradiated cells (about 150 and 110 adducts per 10(6) nucleotides, respectively, at a 500 J/m2 254 nm-UV dose). Formation of photoproducts in a MAR (matrix attached region) sequence from the mouse kappa immunoglobulin gene irradiated in vitro was examined as well. The MAR sequence showed a two-fold higher level of adducts as compared to non-MAR DNA. The effect of photoproducts on complex-formation between MAR DNA and proteins of the nuclear matrix was studied in vitro. The amount of UV-induced adducts was 1.5-fold higher in matrix-bound fraction as compared to non-fractionated DNA (and five-fold higher as compared to unbound fraction), which possibly resulted from preferential binding of lesion-containing DNA fragments to the nuclear matrix proteins.


Asunto(s)
Aductos de ADN/metabolismo , ADN/efectos de la radiación , Proteínas Nucleares/efectos de la radiación , Animales , ADN/metabolismo , Daño del ADN , Humanos , Cadenas kappa de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/efectos de la radiación , Linfocitos/efectos de la radiación , Ratones , Matriz Nuclear/genética , Matriz Nuclear/metabolismo , Matriz Nuclear/efectos de la radiación , Proteínas Nucleares/metabolismo
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