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1.
Georgian Med News ; (347): 70-76, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38609117

RESUMEN

The Nitrosogenesis of skin cancer is a modern newly introduced concept in medicine, mainly concerning melanoma, but also keratinocytic cancers such as basal cell carcinoma. The nitroso-contamination of more than 300 drugs worldwide and the permanent (relatively short-term) intake of mutagen-contaminated drugs could create serious prerequisites for the development of skin cancer. Retrospective but also prospective analyses following potentially contaminated polymedication with a heterogeneous type of nitrosamines in real patients are indicative of a causal connection rather than a sporadic association between 1) intake of a possibly nitrosamine-contaminated drug and 2) generation of keratinocytic skin cancer. The pathogenesis of high-risk periocular localized basal cell carcinomas was until recently shrouded in mystery as it was mainly and until now associated with 1) intake of phototoxic drugs and 2) intense exposure to UV radiation (without intake of drugs), 3) congenital or acquired immunodeficiencies, and 4) Goltz Gorlin syndrome or 5) Xeroderma pigmentosum. Nitrosamines/ NDSRIs within the framework of polycotaminated drug intake appear to be one reasonable additional explanation for the association between carcinogen intake and subsequent skin cancer development and progression, and a relatively short-term one at that. Recently published scientific data provide information on a new ability of some of the nitrosamines - namely that some of them are photocarcinogenic or genotoxic after activation with UVA radiation. We present 4 patients who developed high-risk periocular localized basal cell carcinomas of the skin after/within the intake of potentially nitrosamine-contaminated drugs. The presented data are confirmatory with respect to previously published scientific observations on the carcinogenic effects of valsartan, candesartan, bisoprolol, metoprolol, perindopril, lisinopril and amlodipine. The contribution of newly validated data concerning potential/actual carcinogenic/genotoxic activity in the article is also due to the following newly announced nitroso preparations: torasemide, moxonidine and mirabegron. The expansion of the ˝bases of the pyramid˝ determining the stability of drug related (Photo) Nitrosogenesis/ Carcinogenesis (in terms of skin cancer generation) is growing daily. Exogenously/drug-induced Nitrosogenesis and the subsequently triggered carcinogenesis are a completely new explanatory concepts concerning the pathogenesis of skin tumors that remained unanalyzed and hidden for decades. Until now. The official lack of 1) availability, and of 2) precise concentrations regarding nitrosamines in medicinal preparations, are some of the most unexplained acts of irresponsibility to end-users and remain for the moment without a definitive answer from either regulators and manufacturers respectively. Polycontamination of polymedication in polymorbid patients remains highly problematic, at least as a cofactor in the development and progression of keratinocytic cancers, and this in the short term. Recently published data but also data from the past are suggestive that nitrosamines in tobacco are pivotal in the development of acquired mutations in p53 and RAS oncogenes in humans and rodents. The same genes are also affected by mutations in keratinocytic cancer patients. The overlapping mutation patterns of UV radiation-induced mutations in target genes such as p53 and RAS with those caused by some nitrosamines is indicative of a synergism available in terms of gene toxicity or possibly photocarcinogenicity of the latter. What leads the scientific community to believe that the nitrosamines in drugs, similar in composition and carcinogenic potency, act differently, is unclear. The link between drug intake, nitrosamine contamination, generation of some acquired mutations and subsequent cancer development becomes more than obvious and logically conditioned. The thesis of the controlled spread of cancer sounds more than logical today because: whoever controls and regulates the spread of carcinogens/mutagens/nitrosamines is also able to control the occurrence and spread of skin cancer. The Pharmaco-oncogenesis of skin cancer is determined by exogenously mediated Nitrosogenesis or the permissive availability for certain nitrosamines in drugs worldwide.


Asunto(s)
Acetanilidas , Carcinoma Basocelular , Imidazoles , Nitrosaminas , Neoplasias Cutáneas , Tiazoles , Humanos , Torasemida , Estudios Prospectivos , Estudios Retrospectivos , Proteína p53 Supresora de Tumor , Carcinogénesis , Transformación Celular Neoplásica , Neoplasias Cutáneas/inducido químicamente , Carcinoma Basocelular/inducido químicamente , Nitrosaminas/toxicidad
2.
Georgian Med News ; (347): 136-141, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38609130

RESUMEN

Oncopharmacogenesis and Drug-Induced Skin cancer related Nitrosogenesis are newly introduced concepts in the medical literature that owe their genesis or presence to the carcinogens/ mutagens, also known as nitrosamines/NDSRIs, which are present in a heterogeneous class of drugs. The contribution to the origin of these 2 concepts is entirely due to 1) the functions and efficacy of FDA in terms of control and identification of these carcinogens, and 2) the establishment of clinicopathological correlations by the dermatologists, occurring during drug intake. According to recent FDA data, the concentration of NDMA in just one metformin tablet could be up to more than 5-fold increased. The intake of 3 to 6 tablets per day should result in a carcinogen intake that is 15 to 30 times elevated within the day and within the monomedication alone. It is these circumstances that paraphrase/ ˝betonate˝ concepts such as Onco-Pharmacogenesis and Drug-mediated Nitrosogenesis of skin cancer. Although not officially declared, these mutagens are present and have been in forced tolerance mode for the last 30-40 years. And after their intake, multiple cancers have been found to develop. The concomitant use of other nitrosamine-contaminated drugs such as losartan/hydrochlorothiazide, metoprolol and nefidipine should certainly not be surprising when it could also be associated with the development of exactly 16 keratinocytic tumours as in the case presented by us. Recent evidence in medical literature has linked the nitrosamine N-nitrosomorpholine (NMOR) with the direct development of its subsequent mutagenic action in rodents following irradiation with UVA. This fact leaves open the question of the potentially available photocarcinogenic action of the other nitrosamines in humans found in medicinal preparations. This is what necessitates a clarification of the concept of Photo-Nitroso-Carcinogenesis/ Oncogenesis in humans and its relationship to skin cancer. The overlap of the mutational patterns of some of the nitrosamine-induced mutations in target genes such as p53 and RAS oncogenes, with those of UV light-induced mutations - or practically the same ones mentioned above, suggest a possible significant role of the Drug-Induced Photo-Nitroso-Carcinogenesis of keratinocyte cancer in the context of Onco-Pharmacogenesis. Future analyses should focus on elucidating the photocarcinogenic effect of nitrosamines in drug preparations and differentiating Skin cancer Nitrosogenesis from ˝pure˝ Photo-Carcinogenesis and Nitroso-Photo-Carcinogenesis. The localization of the tumors in the area of the UV-exposed sites within the potential/actual contamination of the 4 preparations (simultaneously) in the described patient are indicative of a possible pathogenetic influence in the context of the already mentioned Nitroso-(Photo)carcinogenesis. Polycontamination of polymedication remains a so far unresolvable problem.


Asunto(s)
Nitrosaminas , Neoplasias Cutáneas , Humanos , Metoprolol , Nifedipino/efectos adversos , Losartán , Dermatólogos , Queratinocitos , Neoplasias Cutáneas/inducido químicamente , Carcinogénesis/inducido químicamente , Carcinógenos/toxicidad , Hidroclorotiazida/efectos adversos , Nitrosaminas/toxicidad , Mutágenos
3.
Akush Ginekol (Sofiia) ; 46(6): 8-12, 2007.
Artículo en Búlgaro | MEDLINE | ID: mdl-17974164

RESUMEN

Human papillomavirus (HPV) infection is common among sexually active individuals and in some cases this infection could coincide with pregnancy in women. In this study, we present our results from investigation for HPV presence in the samples of 50 women with spontaneous abortions. Detection and typing of HPV were carried out by polymerase chain reaction (PCR), using the primers designed to amplify E6/E7 gene sequences of HPV-16, 18 and L1 gene region of HPV-6, 11. HPV DNA was found in 1.5% (3/50) of the clinical samples tested (HPV-16 in one patient, HPV-18--in another one and HPV-16 and HPV-18--in the third patient. Our results support the hypothesis that HPV might be associated with some cases of spontaneous abortions. However, a bigger number of cases are needed for further studies to assess the actual risk of this virus in pregnancy.


Asunto(s)
Aborto Espontáneo/virología , Papillomavirus Humano 16/aislamiento & purificación , Papillomavirus Humano 18/aislamiento & purificación , Infecciones por Papillomavirus/complicaciones , Aborto Espontáneo/etiología , Femenino , Genes Virales , Humanos , Infecciones por Papillomavirus/virología , Placenta/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
4.
Genes Dev ; 15(16): 2146-60, 2001 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-11511545

RESUMEN

E2F is a heterogenous transcription factor and its role in cell cycle control results from the integrated activities of many different E2F family members. Unlike mammalian cells, that have a large number of E2F-related genes, the Drosophila genome encodes just two E2F genes, de2f1 and de2f2. Here we show that de2f1 and de2f2 provide different elements of E2F regulation and that they have opposing functions during Drosophila development. dE2F1 and dE2F2 both heterodimerize with dDP and bind to the promoters of E2F-regulated genes in vivo. dE2F1 is a potent activator of transcription, and the loss of de2f1 results in the reduced expression of E2F-regulated genes. In contrast, dE2F2 represses the transcription of E2F reporters and the loss of de2f2 function results in increased and expanded patterns of gene expression. The loss of de2f1 function has previously been reported to compromise cell proliferation. de2f1 mutant embryos have reduced expression of E2F-regulated genes, low levels of DNA synthesis, and hatch to give slow-growing larvae. We find that these defects are due in large part to the unchecked activity of dE2F2, since they can be suppressed by mutation of de2f2. Examination of eye discs from de2f1; de2f2 double-mutant animals reveals that relatively normal patterns of DNA synthesis can occur in the absence of both E2F proteins. This study shows how repressor and activator E2Fs are used to pattern transcription and how the net effect of E2F on cell proliferation results from the interplay between two types of E2F complexes that have antagonistic functions.


Asunto(s)
Proteínas de Ciclo Celular , Proteínas de Unión al ADN , Proteínas de Drosophila , Factores de Transcripción/antagonistas & inhibidores , Alelos , Animales , Animales Modificados Genéticamente , Ciclo Celular , Drosophila/genética , Drosophila/fisiología , Factores de Transcripción E2F , Factor de Transcripción E2F2 , Ojo , Eliminación de Gen , Regulación de la Expresión Génica , Fenotipo , Proteína de Retinoblastoma , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/fisiología , Transcripción Genética/fisiología
5.
Mol Gen Genet ; 263(1): 119-30, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10732680

RESUMEN

The hexameric regulatory protein ArgR formed by arginine-mediated dimerization of identical trimers governs the expression of genes required for arginine metabolism and some other genes in mesophilic and moderately thermophilic bacteria. We have cloned the argR gene from two hyperthermophilic bacteria of the genus Thermotoga. The two-domain ArgR proteins encoded by T. neapolitana and T. maritima share a low degree of sequence similarity with other bacterial arginine repressors. The ArgR protein from T. neapolitana binds to an operator located just upstream of its coding sequence and, therefore, the argR gene may be autoregulated. The protein has extremely high intrinsic thermostability and tolerance to urea. Moreover, its binding to target DNA increases the melting temperature by approximately 15 degrees C. The formation of oligomeric ArgR-DNA complexes is a function of protein concentration, with hexameric complexes being favoured at higher concentrations. In the presence of arginine the hyperthermophilic ArgR protein binds to its own operator, argRo, only by forming hexamer ArgR-DNA complexes, whereas both trimer-DNA and hexamer-DNA complexes are detected in the absence of arginine. However, the affinity of T. neapolitana ArgR for DNA has been found to be higher for a mixture of trimers and non-bound hexamers than for arginine-bound hexamers. Our data indicate that genes for arginine biosynthesis are clustered in a putative operon, which could also be regulated by the ArgR protein, in the hyperthermophilic host.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Bacilos Gramnegativos Anaerobios Rectos, Curvos y Espirales/metabolismo , Proteínas Represoras/química , Proteínas Represoras/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Secuencia de Bases , Clonación Molecular , Cartilla de ADN/genética , ADN Bacteriano/genética , Proteínas de Unión al ADN/genética , Estabilidad de Medicamentos , Bacilos Gramnegativos Anaerobios Rectos, Curvos y Espirales/genética , Calor , Datos de Secuencia Molecular , Regiones Operadoras Genéticas , Filogenia , Estructura Cuaternaria de Proteína , Proteínas Represoras/genética , Homología de Secuencia de Aminoácido , Thermotoga maritima/genética , Thermotoga maritima/metabolismo
6.
Mol Cell ; 4(1): 75-83, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10445029

RESUMEN

Genetic and biochemical studies indicate that the evolutionarily conserved Swi/Snf complex acts at a subset of genes to help transcriptional activators function on chromatin templates. The mechanism by which this complex is targeted to specific chromosomal loci remains unknown. We show that Swi/Snf is required for expression of the yeast histone HTA1-HTB1 locus because of the role of Hir1p and Hir2p corepressors in negatively regulating transcription. Snf5p, Snf2p/Swi2p, and Swi3p, three components of the yeast Swi/Snf complex, coimmunoprecipitate with each Hir protein, and Snf5p is maximally associated with the HTA1-HTB1 promoter when the Hir-based repression system is intact and the Swi/Snf complex is functional. The data support a role for the Hir repressors in the gene-specific targeting of Swi/Snf.


Asunto(s)
Histonas/genética , Proteínas Represoras/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Transactivadores , Transcripción Genética/genética , Adenosina Trifosfatasas , Proteínas Cromosómicas no Histona , Proteínas de Unión al ADN/genética , Evolución Molecular , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Mutación , Proteínas Nucleares/genética , Regiones Promotoras Genéticas , Proteína SMARCB1 , Factores de Transcripción/genética
7.
Gene ; 212(2): 167-77, 1998 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-9611259

RESUMEN

We have shown that the B. stearothermophilus argCJBD genes form a single operon. In B. stearothermophilus, a specific repressor governs operon expression by binding to the argCo operator site overlapping the Parg promoter sequence (Dion et al., 1997). Therefore, the enzymatic and transcriptional analyses performed in this work did not reflect the potential strength of Parg in the native host. For evaluation of the Parg promoter strength, E. coli was used as a host since its own ArgR repressor does not interact with the B. stearothermophilus heterologous operator. Parg-promoted argC gene expression dramatically increased, reaching up to 38% of the total protein in E. coli cells. An AT-rich sequence upstream of a -35 site of Parg was found to be indispensable for the promoter strength. Plasmids carrying the B. stearothermophilus argCJBD operon linked with its Parg/argCo region were unstable in E. coli. Stabilization of plasmids was achieved by repression of B. stearothermophilus arg genes through the action of the B. subtilis AhrC repressor.


Asunto(s)
Acetiltransferasas/genética , Aldehído Oxidorreductasas , Arginina/genética , Proteínas Bacterianas/genética , Escherichia coli/genética , Geobacillus stearothermophilus/genética , Operón , Regiones Promotoras Genéticas , Bacillus subtilis/genética , Secuencia de Bases , Genes Bacterianos , Factores de Integración del Huésped , Datos de Secuencia Molecular , Operón/genética , Secuencias Reguladoras de Ácidos Nucleicos
8.
Int J Gynaecol Obstet ; 47(2): 147-50, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7843484

RESUMEN

OBJECTIVE: The aim of the study was to evaluate the possibilities of endovaginal ultrasound in the preoperative clinical assessment of patients with endometrial carcinoma. METHOD: Sixty-four postmenopausal women with a diagnosis of endometrial carcinoma after dilatation and curettage were scanned before operation with a 7.5-MHz endovaginal probe. RESULTS: The location of the process and depth of myometrial invasion were estimated correctly in the vast majority of patients. Spread beyond the uterus and distance from the serosa could not be estimated precisely. CONCLUSION: Preoperative evaluation and staging of endometrial carcinoma are possible and useful for gynecologists, as they provide information on tumor location, depth of myometrial invasion, and involvement, if present, of the lower uterine segment or cervix.


Asunto(s)
Neoplasias Endometriales/diagnóstico por imagen , Neoplasias Endometriales/patología , Neoplasias Endometriales/cirugía , Endometrio/patología , Femenino , Humanos , Persona de Mediana Edad , Miometrio/patología , Invasividad Neoplásica , Estadificación de Neoplasias , Posmenopausia , Cuidados Preoperatorios , Ultrasonografía
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