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1.
Phys Rev Lett ; 131(22): 222502, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38101341

RESUMEN

Collinear laser spectroscopy was performed on the isomer of the aluminium isotope ^{26m}Al. The measured isotope shift to ^{27}Al in the 3s^{2}3p ^{2}P_{3/2}^{○}→3s^{2}4s ^{2}S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of ^{26m}Al, resulting in R_{c}=3.130(15) fm. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed ß decay of ^{26m}Al. Its corrected Ft value, important for the estimation of V_{ud} in the Cabibbo-Kobayashi-Maskawa matrix, is thus shifted by 1 standard deviation to 3071.4(1.0) s.

2.
Phys Rev Lett ; 128(2): 022502, 2022 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35089728

RESUMEN

Collinear laser spectroscopy is performed on the nickel isotopes ^{58-68,70}Ni, using a time-resolved photon counting system. From the measured isotope shifts, nuclear charge radii R_{c} are extracted and compared to theoretical results. Three ab initio approaches all employ, among others, the chiral interaction NNLO_{sat}, which allows an assessment of their accuracy. We find agreement with experiment in differential radii δ⟨r_{c}^{2}⟩ for all employed ab initio methods and interactions, while the absolute radii are consistent with data only for NNLO_{sat}. Within nuclear density functional theory, the Skyrme functional SV-min matches experiment more closely than the Fayans functional Fy(Δr,HFB).

3.
Int Urogynecol J ; 32(11): 2937-2946, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34351464

RESUMEN

INTRODUCTION AND HYPOTHESIS: The objective was to examine the effect of the surgical removal of vaginally placed prolapse and incontinence mesh on sexual function. We hypothesize that patients with painful complications of mesh will experience improvement in dyspareunia and sexual function after mesh removal. METHODS: The eligible cohort consisted of 133 women who presented with a new onset of pain attributed to mesh-augmented incontinence or prolapse surgery and who elected to undergo mesh removal between 1 August 2012 and 1 July 2013. Sexual function symptoms were assessed before and after mesh removal surgery using the Pelvic Organ Prolapse and Urinary Incontinence Sexual Function Questionnaire short form (PISQ-12). Multivariate analysis was performed to identify predictors of improvement in dyspareunia. RESULTS: Ninety-four patients undergoing mesh removal completed a pre-operative questionnaire, 63 of whom also completed a post-operative questionnaire. After mesh removal, there was a nearly 50% reduction in the proportion of women reporting always experiencing post-operative pain with intercourse among those experiencing pre-operative pain. There was a statistically significant quantitative improvement in pain with intercourse after mesh removal based on mean change score of PISQ-12 question 5 "How often do you experience pain with intercourse?". In multivariate analysis, only history of vaginal delivery was associated with symptom improvement. CONCLUSION: Removal of transvaginal prolapse mesh is associated with improvement in self-reported dyspareunia based on a standardized question on a validated instrument in a small cohort of women. Although larger studies are needed to confirm the relationship between mesh-augmented surgeries and post-procedural dyspareunia, these data suggest that consideration of mesh removal is a reasonable step for patients with painful intercourse attributed to mesh-augmented prolapse and incontinence surgeries.


Asunto(s)
Dispareunia , Prolapso de Órgano Pélvico , Cabestrillo Suburetral , Dispareunia/etiología , Dispareunia/cirugía , Femenino , Humanos , Prolapso de Órgano Pélvico/complicaciones , Prolapso de Órgano Pélvico/cirugía , Cabestrillo Suburetral/efectos adversos , Mallas Quirúrgicas/efectos adversos , Encuestas y Cuestionarios
4.
J Urol ; 204(4): 754-759, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32294397

RESUMEN

PURPOSE: We evaluated and identified baseline factors associated with change in health related quality of life among patients with interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome. MATERIALS AND METHODS: A total of 191 men and 233 women with interstitial cystitis/bladder pain syndrome or chronic prostatitis/chronic pelvic pain syndrome (collectively referred to as urologic chronic pelvic pain syndrome) were followed for 12 months with bimonthly completion of the Short Form 12 to assess general mental and physical health related quality of life, and with biweekly assessment of condition specific health related quality of life using the Genitourinary Pain Index. A functional clustering algorithm was used to classify participants as improved, stable or worsened for each health related quality of life measure. Ordinal logistic regression was used to determine baseline factors associated with change. RESULTS: Physical health related quality of life improved in 22% of the participants, mental health related quality of life improved in 25% and condition specific health related quality of life improved in 47%. Better baseline physical health related quality of life, older age and the presence of nonurological symptoms were associated with lower likelihood of improvement in physical health related quality of life. Better baseline mental health related quality of life, female sex, and greater baseline depression and stress were associated with a lower likelihood of improvement in mental health related quality of life. Better baseline condition specific health related quality of life and more severe baseline urologic chronic pelvic pain syndrome pain symptoms were associated with a lower likelihood of improvement in condition specific health related quality of life. CONCLUSIONS: While several nonurologic chronic pelvic pain syndrome factors influenced the trajectory of general health related quality of life over time, only condition specific baseline health related quality of life and urologic chronic pelvic pain syndrome symptoms were associated with urologic chronic pelvic pain syndrome specific health related quality of life change. Significant differences in how urologic chronic pelvic pain syndrome impacts various aspects of health related quality of life suggest a multidisciplinary approach to assessment and treatment of these patients.


Asunto(s)
Cistitis Intersticial , Prostatitis , Calidad de Vida , Investigación Biomédica , Correlación de Datos , Femenino , Humanos , Masculino , Estudios Prospectivos , Factores de Tiempo
5.
Phys Rev Lett ; 124(13): 132502, 2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32302185

RESUMEN

We present the first laser spectroscopic measurement of the neutron-rich nucleus ^{68}Ni at the N=40 subshell closure and extract its nuclear charge radius. Since this is the only short-lived isotope for which the dipole polarizability α_{D} has been measured, the combination of these observables provides a benchmark for nuclear structure theory. We compare them to novel coupled-cluster calculations based on different chiral two- and three-nucleon interactions, for which a strong correlation between the charge radius and dipole polarizability is observed, similar to the stable nucleus ^{48}Ca. Three-particle-three-hole correlations in coupled-cluster theory substantially improve the description of the experimental data, which allows to constrain the neutron radius and neutron skin of ^{68}Ni.

6.
Phys Rev Lett ; 122(19): 192502, 2019 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-31144969

RESUMEN

The change in mean-square nuclear charge radii δ⟨r^{2}⟩ along the even-A tin isotopic chain ^{108-134}Sn has been investigated by means of collinear laser spectroscopy at ISOLDE/CERN using the atomic transitions 5p^{2} ^{1}S_{0}→5p6 s^{1}P_{1} and 5p^{2} ^{3}P_{0}→5p6s ^{3}P_{1}. With the determination of the charge radius of ^{134}Sn and corrected values for some of the neutron-rich isotopes, the evolution of the charge radii across the N=82 shell closure is established. A clear kink at the doubly magic ^{132}Sn is revealed, similar to what has been observed at N=82 in other isotopic chains with larger proton numbers, and at the N=126 shell closure in doubly magic ^{208}Pb. While most standard nuclear density functional calculations struggle with a consistent explanation of these discontinuities, we demonstrate that a recently developed Fayans energy density functional provides a coherent description of the kinks at both doubly magic nuclei, ^{132}Sn and ^{208}Pb, without sacrificing the overall performance. A multiple correlation analysis leads to the conclusion that both kinks are related to pairing and surface effects.

7.
J Med Entomol ; 45(3): 476-82, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18533443

RESUMEN

The epidemiological risk of infection by Trypanosoma cruzi Chagas in human populations of western Mexico is still under study. Although most vectors in this region and their vector capability are already known, new studies estimating the risk and the importance of individual Triatominae species (Hemiptera: Reduviidae) for T. cruzi transmission are necessary. For 1 yr, every month, > 400 human dwellings and their surroundings in eight communities of two western Mexico states were searched for triatomines. More than 1,000 specimens representing four species were collected and checked for T. cruzi infection. Based on the usual entomological indices, only the inhabitants of Gavilán El Progreso-La Villita are at serious risk of vectorial infection by T. cruzi. A population of Meccus longipennis (Usinger) was found living in peridomestic rock pile boundary walls after an insecticide spraying. It was confirmed the major role of peridomestic habitats as shelter areas for triatomines, particularly in rock pile boundary walls and chicken roosts. Triatominae presence also was verified in certain sylvatic habitats, including primarily heaps of stones. The important role of M. longipennis in the potential transmission of T. cruzi in the region and the secondary role of M. picturatus (Usinger) and Triatoma barberi Usinger also were confirmed. Null colonization of houses by T. barberi, which was collected primarily in peridomestic habitats, differs from its common intradomiciliary collection in other studies. Meccus pallidipennis (Stål) most probably does not exist in Nayarit. Meccus mazzottii (Usinger) and Meccus phyllosomus (Burmeister) are no longer found in Nayarit and Jalisco. Additional studies are necessary to determine the current epidemiological situation in other areas of western Mexico.


Asunto(s)
Enfermedad de Chagas/transmisión , Insectos Vectores , Triatominae/parasitología , Trypanosoma cruzi/fisiología , Animales , Enfermedad de Chagas/parasitología , México/epidemiología , Triatominae/clasificación , Triatominae/fisiología
8.
Cancer Res ; 56(1): 127-37, 1996 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-8548752

RESUMEN

Effector-target cell conjugate formation is an essential step during lymphokine-activated killer (LAK) cell-mediated cytotoxicity. Protein phosphorylation changes in human LAKs after contact with NK-resistant (LAK-sensitive) tumors were examined by two-dimensional SDS-PAGE. Exposure to either SK-Mel-1 (melanoma) or Raji (lymphoma) targets led to increased phosphorylation of two M(r) 65,000 LAK proteins, pp65a and pp65b, with isoelectric points of 5.1 and 5.2, respectively. Phosphorylation of both substrates was initiated between 1 and 5 min after coincubation with tumor targets. Contact between LAKs and targets was required for p65 phosphorylation because soluble tumor factors failed to induce phosphorylation. Normal peripheral blood lymphocyte targets, which are bound very poorly by LAKs and are resistant to killing, failed to induce LAK p65 phosphorylation. The broad protein kinase inhibitor staurosporine inhibited phosphorylation of pp65a and pp65b, supporting the hypothesis that activation of a LAK protein kinase leads to p65 phosphorylation. Cross-linking of CD16 (Fc gamma RIIIA), which mediates antibody-dependent cellular cytotoxicity in LAKs, also led to increased pp65a and pp65b phosphorylation. Collectively, these data provide correlative evidence that p65 phosphorylation may be involved in the cytolytic function of LAKs.


Asunto(s)
Citotoxicidad Inmunológica/inmunología , Células Asesinas Activadas por Linfocinas/inmunología , Linfoma/inmunología , Melanoma/inmunología , Proteínas/metabolismo , Comunicación Celular , Técnicas de Cocultivo , Electroforesis en Gel Bidimensional , Humanos , Células Asesinas Activadas por Linfocinas/metabolismo , Activación de Linfocitos , Linfoma/metabolismo , Melanoma/metabolismo , Fosforilación , Células Tumorales Cultivadas
9.
Cancer Res ; 56(1): 138-44, 1996 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-8548753

RESUMEN

Contact between lymphokine-activated killer (LAK) cells and natural killer-resistant tumor targets SK-Mel-1 (human melanoma) or Raji (human lymphoma) stimulates phosphorylation of two M(r) 65,000 LAK proteins (pp65a and pp65b) with nearly identical isoelectric points. Phosphoamino acid analysis of pp65a and pp65b detected phosphorylation exclusively on serine residues. Phosphotyrosine could not be detected on either substrate after immunoblotting with an antiphosphotyrosine antibody, and herbimycin A treatment failed to inhibit p65 phosphorylation induced by target contact. However, phorbol myristate acetate treatment alone induced LAK pp65a and pp65b phosphorylation, suggesting phosphorylation may be mediated by protein kinase C or a protein kinase C-regulated kinase. The molecular weight and isoelectric points of pp65a and pp65b are similar to that reported for the human actin-bundling protein, L-plastin (L-fimbrin). On two-dimensional SDS-PAGE gel immunoblots, a peptide specific anti-L-plastin antiserum bound to pp65a and pp65b, suggesting that the phosphoproteins are similar or identical to L-plastin. In addition, two adjacent M(r) 65,000 LAK proteins were also detected by the antiserum and may correspond to unphosphorylated forms of L-plastin. On the basis of known properties of phosphorylated L-plastin, it is hypothesized that p65 phosphorylation in LAKs may regulate adhesion to tumor targets.


Asunto(s)
Células Asesinas Activadas por Linfocinas/metabolismo , Linfoma/inmunología , Melanoma/inmunología , Fosfoproteínas/metabolismo , Técnicas de Cocultivo , Citotoxicidad Inmunológica , Electroforesis en Gel Bidimensional , Humanos , Células Asesinas Activadas por Linfocinas/inmunología , Glicoproteínas de Membrana , Proteínas de Microfilamentos , Proteínas de Neoplasias/metabolismo , Fosforilación , Células Tumorales Cultivadas
10.
Australas Phys Eng Sci Med ; 38(2): 217-21, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26076746

RESUMEN

This policy statement, which is the fifth of a series of documents being prepared by the Asia-Oceania Federation of Organizations for Medical Physics Professional Development Committee, gives guidance on how clinical medical physicists' careers should progress from their initial training to career end. It is not intended to be prescriptive as in some AFOMP countries career structures are already essentially defined by employment awards and because such matters will vary considerably from country to country depending on local culture, employment practices and legislation. It is intended to be advisory and set out options for member countries and employers of clinical medical physicists to develop suitable career structures.


Asunto(s)
Movilidad Laboral , Educación Profesional , Física Sanitaria/educación , Sociedades Científicas , Curriculum , Empleo , Humanos
11.
Environ Health Perspect ; 106 Suppl 6: 1325-30, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9860888

RESUMEN

Current methods to estimate the quantitative cancer risk of complex mixtures of polycyclic aromatic hydrocarbons (PAH) such as coal tar assume that overall potency can be derived from knowledge of the concentration of a few carcinogenic components such as benzo[a]pyrene (B[a]P). Genotoxic damage, such as DNA adducts, is thought to be an essential aspect of PAH-induced tumorigenesis and could be a biomarker for exposure useful for estimating risk. However, the role of B[a]P and the relationship of adduct formation in tumorigenesis have not been tested rigorously in models appropriate for human health risk assessment. Therefore, we directly compared tumor induction and adduct formation by B[a]P and coal tars in several experimental protocols, including one broadly accepted and used by regulators. We found that B[a]P content did not account for tumor incidences after exposure to coal tars. DNA adducts were found in both tumors and tumor-free tissue and tumor outcomes were not predicted by either quantitation of total DNA adducts or by the DNA adduct formed by B[a]P. These data suggest that risk assessments based on B[a]P content may not predict accurately risk to human health posed by environmental PAH.


Asunto(s)
Benzo(a)pireno/toxicidad , Carcinógenos/toxicidad , Alquitrán/toxicidad , Aductos de ADN/efectos de los fármacos , Administración Oral , Animales , Pruebas de Carcinogenicidad , Interacciones Farmacológicas , Femenino , Inyecciones Intraperitoneales , Ratones , Ratones Endogámicos , Medición de Riesgo , Factores de Tiempo
12.
Radiat Res ; 110(1): 45-60, 1987 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3562792

RESUMEN

A rat mammary adenocarcinoma cell clone, MTC, and a rat lung endothelial cell clone, RLE cl.4, both syngeneic to the Fisher 344 rat, were compared for proteins synthesized at 37 degrees C and after a 1-h, 42 degrees C heat dose. The heat stress-induced or -enhanced synthesis of a series of molecular mass groups and isoelectric point species (isomers) was observed in both equilibrium and nonequilibrium two-dimensional gel electrophoresis. Tumor and endothelial cell heat-stress proteins (hsp) were strikingly similar with most hsp in 11 or 13 molecular mass groups having from 1 to 12 major isomers. In comparing the two cell types, 6 of about 23 major hsp isomers appeared different in equilibrium pH gels, with tumor cells seemingly exhibiting less synthesis of these 6 isomers. Four additional endothelial cell hsp isomers were apparent in nonequilibrium pH gels. Since two of these later hsp can be found at higher heat doses in tumor cells, some of these apparent differences between tumor and endothelial cells may be attributable to different dose ranges for induction of hsp. Fluorograms and silver-stained gels showed that several hsp were being synthesized at appreciable levels in unheated cells. However, there were hsp whose synthesis appeared to be de novo rather than representing enhanced synthesis of existing proteins. These last two observations were made in both tumor and normal cells. The constitutive levels of hsp synthesis appeared to be generally similar in unheated tumor and normal cells in vitro with few exceptions. These results indicate the presence of few unique hsp in syngeneic tumor and normal cells in vitro. However, focusing subsequent studies on the few differences may lead to insights concerning hyperthermic biology of tumor and normal cells, phenotypic differences between these cells, and roles of some hsp.


Asunto(s)
Adenocarcinoma/metabolismo , Endotelio/metabolismo , Proteínas de Choque Térmico/biosíntesis , Neoplasias Mamarias Experimentales/metabolismo , Animales , Punto Isoeléctrico , Peso Molecular , Proteínas de Neoplasias/metabolismo , Ratas , Ratas Endogámicas F344
13.
Chem Biol Interact ; 27(2-3): 177-90, 1979 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-498353

RESUMEN

The in vivo binding of radioactive N-2-acetylaminofluorene (AAF) and N-hydroxy-2-acetylaminofluorene (N-OH-AAF) to the DNA of rat liver chromatin was examined. The chromatin was fractionated into putative transcriptionally active and inactive fractions by hydrodynamic shearing and subsequent glycerol gradient centrifugation, DNAase II digestion followed by MgCl2 aggregation of transcriptionally inactive chromatin, or mild digestion with micrococcal nuclease. Carcinogens were administered for various times prior to sacrifice. Irrespective of the duration of exposure, no preferential binding of either carcinogen to DNA was detected in any of the fractions prepared by hydrodynamic shearing of DNAase II digestion. When micrococcal nuclease was utilized, a 2-fold increase in carcinogen bound to the DNA of that chromatin fraction containing the smallest molecular weight fragments was detected. These small molecular weight fragments produced by micrococcal nuclease have been postulated to be derived from in vivo transcriptional units. Additionally, when DNAase II was used to probe chromatin from rat livers which had been exposed to a carcinogenic regimen of AAF, no preferential binding of radioactive N-OH-AAF to the DNA of any chromatin fraction was detected.


Asunto(s)
2-Acetilaminofluoreno/análogos & derivados , 2-Acetilaminofluoreno/metabolismo , Cromatina/metabolismo , ADN/metabolismo , Hidroxiacetilamino Fluoreno/metabolismo , Animales , Centrifugación por Gradiente de Densidad , ADN/aislamiento & purificación , Desoxirribonucleasas , Dieta , Endonucleasas , Hígado/ultraestructura , Masculino , Nucleasa Microcócica , Ratas , Factores de Tiempo
14.
Chem Biol Interact ; 96(3): 207-21, 1995 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-7750161

RESUMEN

The potential non-additive interactions of polynuclear aromatic hydrocarbon (PAH) mixtures as inducers of Cyp1a-1 and Cyp1a-2 gene expression were investigated in B6C3F1 mice using a reconstituted PAH mixture. The chemical composition (% by weight) of the reconstituted PAH mixture was: 2-ring PAHs--indan (0.22), naphthalene (23.8), 2-methylnaphthalene (23.2) and 1-methylnaphthalene (13.3); 3-ring PAHs--acenaphthylene (7.7), acenaphthene (0.6), dibenzofuran (0.7), fluorene (4.3), phenanthrene (10.5) and anthracene (3.4); > or = 4-ring PAHs--fluoranthene (2.4), pyrene (4.3), benz[a]anthracene (1.4), chrysene (1.5), benzo[b]fluoranthene (0.8), benzo[k]fluoranthene (0.9) and benzo[a]pyrene (0.9). The composition of the 2-, 3- and > or = 4-ring PAH fractions were based on the relative concentration of individual PAHs as noted above. The > or = 4-ring PAH fractions were based on the relative concentration of individual PAHs as noted above. The > or = 4-ring PAH fraction and reconstituted mixture induced hepatic microsomal ethoxyresorufin O-deethylase (EROD) activity and Cyp1a-1 mRNA levels, whereas the 2- and 3-ring PAHs were only weakly active. Direct comparison of the potencies of the reconstituted mixture and > or = 4-ring PAHs showed that the Cyp1a-1 induction activity of the reconstituted mixture was due to the > or = 4-ring PAHs. The reconstituted PAH mixture and > or = 4-ring PAHs also induced Cyp1a-2 hepatic mRNA levels and microsomal methoxyresorufin O-deethylase (MROD) activity; however, their dose-response curves indicated that the reconstituted PAH mixture was more potent as a Cyp1a-2 inducer than the > or = 4 ring PAHs. The differences in potency were due to 3-ring PAHs which were found to be strong inducers of hepatic Cyp1a-2 mRNA levels and microsomal MROD activity at the lowest dose administered (37 mg/kg). The 3-ring mixture caused a maximal 29-fold increase in hepatic MROD activity at a dose of 292 mg/kg, but only 28% of maximal induction of EROD activity. Northern analysis of liver mRNA from mice treated with 3-ring PAHs showed that there was minimal induction of Cyp1a-1 mRNA levels. The 3-ring PAHs did not competitively bind to the mouse hepatic cytosolic aryl hydrocarbon (Ah) receptor suggesting that 3-ring PAHs are a new class of Cyp1a-2 inducers which do not act through the Ah receptor.


Asunto(s)
Sistema Enzimático del Citocromo P-450/genética , Hígado/enzimología , Oxidorreductasas/genética , Compuestos Policíclicos/farmacología , Animales , Citocromo P-450 CYP1A2 , Citosol/enzimología , Inducción Enzimática/efectos de los fármacos , Femenino , Expresión Génica/efectos de los fármacos , Heterocigoto , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Microsomas Hepáticos/enzimología , Compuestos Policíclicos/química , ARN Mensajero/genética , Receptores de Hidrocarburo de Aril/metabolismo , Relación Estructura-Actividad
15.
Chem Biol Interact ; 89(2-3): 141-58, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8269543

RESUMEN

The relative potencies of benzo[a]pyrene and a complex mixture of polynuclear aromatic hydrocarbons (PAHs) produced as by-products of manufactured gas plant (MGP) residues as inducers of hepatic microsomal ethoxyresorufin O-deethylase (EROD) activity were determined in the B6C3F1 mouse. The ED50 values for the induction response were 78 and 65 mg/kg for benzo[a]pyrene and the MGP-PAH mixture, respectively. Analysis of the MGP-PAH mixture indicated that benzo[a]pyrene and other compounds containing four or more rings and which are known to induce EROD activity were only present as trace components of this mixture. A comparison of the EROD induction potencies of benzo[a]pyrene and the MGP-PAH mixture showed that the mixture was approximately 706 times more potent than expected based on its benzo[a]pyrene content (0.17%). This induced P-450 activity could significantly increase the metabolism of the carcinogenic PAHs and thereby modulate the overall carcinogenicity of the mixture. The apparent synergistic activity of the MGP-PAH mixture was further investigated by comparing the activities of this mixture and benzo[a]pyrene for several other aryl hydrocarbon (Ah) receptor-mediated responses including (i) induction of hepatic CYP1A1 mRNA levels, (ii) transformation of the rat cytosolic Ah receptor to a complex which binds to a dioxin responsive element, (iii) induction of EROD activity and (iv) antiestrogenicity in MCF-7 human breast cancer cells, and (v) inhibition of the splenic plaque-forming cell (PFC) response to both T cell-dependent and independent antigens in B6C3F1 mice. For the EROD and CYP1A1 mRNA induction and cytosolic transformation activities and immunosuppressive effects, the MGP-PAH mixture was approximately 100-900 times more potent as an Ah receptor agonist than expected based on its benzo[a]pyrene content. The synergistic activity was lower (19-fold) for the antiestrogenic response in MCF-7 cells. The reason for the synergistic effects of the MGP-PAH mixture were not due to contamination of the mixture by 2,3,7,8-tetrachlorodibenzo-p-dioxin and related compounds and the results suggest that the enhanced potency of the mixture is due to unknown interactions between the individual PAHs present in the mixture.


Asunto(s)
Carcinógenos/farmacología , Compuestos Policíclicos/farmacología , Receptores de Hidrocarburo de Aril/efectos de los fármacos , Animales , Secuencia de Bases , Catepsina D/metabolismo , Citocromo P-450 CYP1A1 , Sistema Enzimático del Citocromo P-450/biosíntesis , Sinergismo Farmacológico , Inducción Enzimática , Precursores Enzimáticos/metabolismo , Femenino , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Datos de Secuencia Molecular , Oxidorreductasas/biosíntesis , Ratas , Bazo/efectos de los fármacos , Células Tumorales Cultivadas
16.
Chem Biol Interact ; 33(2-3): 149-61, 1981 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7460064

RESUMEN

Conformationally distinct chromatin populations were utilized as substrates to quantitate the relative amount of and accessibility of internal 5'-phosphomonoester breaks in DNA-chromatin. In these studies, a constant amount of chromatin as well as deproteinized DNA derived from the respective chromatin sample was titrated with increasing quantities of adenylated polynucleotide ligase intermediate. This enzyme intermediate releases its AMP moiety while repairing a DNA single strand interruption, release of AMP being directly proportional to the number of internal 5'-phosphomonoester breaks repaired. Results of this study indicate that the ability of polynucleotide ligase to repair DNA breaks within chromatin was affected by the conformational state of the chromatin. The degree of conformational constraint present in a given chromatin, therefore, determined the capacity of the enzyme to repair internal DNA 5'-phosphomonoester breaks.


Asunto(s)
Adenosina Monofosfato/metabolismo , Cromatina/metabolismo , Reparación del ADN , Polinucleótido Ligasas/metabolismo , Animales , Dicroismo Circular , Técnicas In Vitro , Masculino , Ratones , Conformación Proteica , Ratas , Ratas Endogámicas ACI
17.
Environ Toxicol Pharmacol ; 5(3): 205-13, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-21781866

RESUMEN

Acenaphthylene is a tricyclic aromatic hydrocarbon which induces hepatic methoxyresorufin O-demethylase (MROD) activity and CYP1A2 mRNA levels in 2 week-old male B6C3F1 mice. In the present study, this induction response was further investigated in genetically-inbred mice which differ in their aryl-hydrocarbon (Ah)-responsiveness. Acenapthylene (300 mg/kg) induced a 5- to 23-fold induction of MROD activity in Ah-nonresponsive (DBA and SJL) and responsive (C3H, C57/BL6, A/J, CBA and B6C3F1) mice. The highest induction response was observed in the DBA strain in which there was a 23- and 15-fold increase in activity in males and females, respectively. Acenaphthylene also caused a 2-fold increase in CYP1A2 mRNA and immunoreactive protein levels in 2 week-old DBA mice; however, this induction response was not observed in 6 week-old animals. For example, MROD activity in 6 week-old DBA mice was induced <2-fold by acenaphthylene, mainly as a consequence of increased basal CYP1A2 expression and MROD activity which, at the age of 6 weeks, approached levels induced by acenaphthylene in the 2 week-old mice. This was also observed by immunohistochemical staining with CYP1A2 antibodies of 2 and 6 week-old hepatic tissue from treated and control mice which also showed that CYP1A2 induction was dependent on the age of the animals.

20.
Curr Opin Urol ; 10(2): 111-6, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10785852

RESUMEN

Transrectal ultrasound guided needle biopsies of the prostate are routinely performed to diagnose and stage prostate cancer. This diagnostic technique is a safe method to diagnose prostate cancer with few major complications but frequent minor complications.


Asunto(s)
Biopsia con Aguja/efectos adversos , Biopsia con Aguja/métodos , Neoplasias de la Próstata/patología , Humanos , Incidencia , Masculino , Complicaciones Posoperatorias/epidemiología , Neoplasias de la Próstata/diagnóstico por imagen , Recto , Factores de Riesgo , Ultrasonografía
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