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1.
Artigo em Inglês | MEDLINE | ID: mdl-37491119

RESUMO

Multiple sclerosis (MS) is a demyelinating disorder in which the myelin sheath covering the central nervous system axons is damaged or lost, disrupting action potential conduction and leading to various neurological complications. The pathogenesis of MS remains unclear, and no effective therapies are currently available. MS is triggered by environmental factors in genetically susceptible individuals. DNA damage and DNA repair failure have been proposed as MS genetic risk factors; however, inconsistent evidence has been found in multiple studies. Therefore, more investigations are needed to ascertain whether DNA damage/repair is altered in this disorder. In this context, therapies that prevent DNA damage or enhance DNA repair could be effective strategies for MS treatment. The overactivation of the extracellular-signal-related kinase 1 and 2 (Erk1/2) pathway can lead to DNA damage and has been linked to MS pathogenesis. In our study, we observed substantially elevated oxidative DNA damage and slower DNA repair rates in an experimentally autoimmune encephalomyelitis animal model of MS (EAE). Moreover, statistical decreases in oxidative DNA strand breaks and faster repair rates were observed in EAE animals injected with the Erk1/2 inhibitor PD98059 (PD). Moreover, the expression of several genes associated with DNA strand breaks and repair changed in EAE mice at both the mRNA and protein levels, as revealed by the RT2 Profiler PCR array and verified by RT-PCR and protein analyses. The treatment with PD mitigated these changes and improved DNA repair gene expression. Our results demonstrate clear associations between Erk1/2 activation, DNA damage/repair, and MS pathology, and further suggest that PD therapy may be a promising adjuvant therapeutic strategy.


Assuntos
Antineoplásicos , Encefalomielite Autoimune Experimental , Esclerose Múltipla , Camundongos , Animais , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/genética , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/genética , Camundongos Endogâmicos , Antineoplásicos/uso terapêutico , Transdução de Sinais , Reparo do DNA , DNA , Camundongos Endogâmicos C57BL
2.
Folia Morphol (Warsz) ; 81(3): 614-631, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34355785

RESUMO

BACKGROUND: Psoriasis is a common autoimmune inflammatory skin disease, with no clear cause, treated with topical agents and phototherapy, conventional immunosuppressant drugs and biologic agents. Stem cell therapy has generated significant interest in regenerative medicine. The aim of this study was to use mesenchymal stem cell (MSC) therapy compared to the topical application of the standard conventional corticosteroid cream. MATERIALS AND METHODS: Forty male adult albino rats were used, divided into four groups, 10 rats each: group I (control), group II (psoriasis-like lesions induced by usage of Aldara cream), group III (treated with betamethasone) and group IV (treated with MSCs). Specimens were stained with haematoxylin and eosin, Masson's trichrome, immune-histochemical technique for CD4, CD8 and CD31. Ultra-sections were prepared for transmission electron microscope (TEM) examination. RESULTS: Mesenchymal stem cells demonstrated efficacy in reduction of disease severity in the form of uniform epidermal thickness covered by a very thin keratin layer. Normally arranged layers of epidermal layers, with a clear border demarcation, were seen between the epidermis and the dermis with apparently intact basement membrane. TEM showed absence of gaps between the tightly connected cells of the basal layer and the resting basement membrane. CONCLUSIONS: Application of MSCs raises hope for developing a new, safe and effective therapy for psoriatic patients, avoiding the side effects of betamethasone.


Assuntos
Células-Tronco Mesenquimais , Psoríase , Animais , Betametasona/metabolismo , Betametasona/farmacologia , Epiderme , Sangue Fetal/metabolismo , Masculino , Psoríase/tratamento farmacológico , Psoríase/metabolismo , Ratos
4.
J Diabetes Metab Disord ; 18(1): 1-6, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31275868

RESUMO

PURPOSE: Glucose monitoring [GM] is a mainstay of diabetes control and management. Improving glycemic control is essential to prevent microvascular complications. However, adherence to GM can be a challenge in children and adolescents. Detecting hypoglycemia is essential for its prevention and treatment. We aim to study the impact of the flash ambulatory glucose monitoring in detecting hypoglycemia and enhancing adherence in children and adolescents with type 1 diabetes. METHODS: The study is prospective involving 3 hospital visits. Children and adolescents with diabetes were enrolled in the study which involved a period on conventional glucose self-monitoring [glucometers] followed by a similar period of monitoring using the flash glucose monitoring device (FreeStyle Libre). Frequency of GM, duration and frequency of hypoglycemia were compared on conventional and the flash monitoring. RESULTS: 75 subjects were studied. Age mean (range) was 11.9 years (2-19). Significant difference was seen in hypoglycemia detection between both testing devices. 68 (94%) and 65 (90%) patients detected nocturnal and diurnal hypoglycemia respectively on Flash monitoring compared to 12 (16.6%) and 30 (41%) on glucometer testing (p < 0.00). Mean (range) duration of hypoglycemia was 95 min (15-330). Statistically-significant difference was found between the frequency of GM on glucometer testing compared with Flash monitoring (2.87 and 11.6/day) (p < 0.001). CONCLUSIONS: Flash monitoring is a useful tool to improve adherence to GM and detecting hypoglycemia [diurnal and nocturnal] in children and adolescents with type 1 diabetes.

5.
J Fr Ophtalmol ; 42(6): 626-641, 2019 Jun.
Artigo em Francês | MEDLINE | ID: mdl-31164292

RESUMO

Behçet's disease is a chronic multisystem disorder characterized by relapsing inflammation for which the underlying histopathology is an occlusive vasculitis. The disease has a high prevalence in the Mediterranean region, Far and Middle Eastern countries. It is clinically characterized by oral and genital ulcerations, ocular inflammatory involvement, skin lesions, vascular involvement and numerous other systemic manifestations. Uveitis is by far the most common ocular manifestation of Behçet's disease. It typically presents in the form of relapsing-remitting panuveitis with retinal vasculitis that may result in severe visual loss. Management of Behçet's uveitis relies on corticosteroid therapy, conventional immunosuppressive drugs and biological agents and requires a close collaboration between ophthalmologist and internist. A better understanding of the auto-inflammatory process and of the role of cytokines implicated in the pathogenesis of Behçet's disease will enable researchers to develop more specific and effective therapy.


Assuntos
Síndrome de Behçet/complicações , Uveíte/etiologia , Adulto , Idade de Início , Segmento Anterior do Olho , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/imunologia , Síndrome de Behçet/terapia , Fatores Biológicos/uso terapêutico , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Segmento Posterior do Olho , Recidiva , Vasculite Retiniana/etiologia , Uveíte/epidemiologia , Uveíte/terapia , Transtornos da Visão/etiologia
6.
Pathologica ; 111(1): 18-23, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31217618

RESUMO

INTRODUCTION: Gastric cancer is considered to be the fourth most common malignancy worldwide and the second cause of cancer deaths. Regarding the cancer stem cells (CSCs) theory, they are a small group of tumor cells with unrestricted self-renewal and differentiation abilities that help tumor formation. There is an interest in the utility of CD133 as a promising marker to detect the tumor stem cell population for a variety of solid malignancies including gastric cancer. Tumors that express stem cell markers such as CD133 are found to be more aggressive tumors with poor prognosis and high liability for recurrence. This study aimed to evaluate the immunohistochemical expression of CD133 in invasive gastric carcinoma and study the relation between CD133 immunohistochemical expression and different clinicopathological parameters. MATERIAL AND METHODS: 77 cases of gastric carcinoma were collected from the surgical pathology unit at the Gastroenterology Center, Mansoura University, Egypt. CD133 expression in tumor tissue was evaluated by immunohistochemistry. RESULTS: CD133 expression positively correlated with tumor metastasis and recurrence. Multivariate analysis revealed CD133 positivity to be an independent prognostic factor for tumor recurrence (P = 0.03). CONCLUSION: CD133 is a good marker that can predict tumor recurrence and metastasis in gastric carcinoma. Even though, studies regarding CSCs are still in their initial stages especially those related to CD133 in gastric cancer.


Assuntos
Antígeno AC133/biossíntese , Biomarcadores Tumorais , Células-Tronco Neoplásicas/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-30959085

RESUMO

Information regarding DNA repair in autism is limited to a few studies, which have reported inconsistent results. Therefore, we designed a study to determine whether DNA repair efficiency is altered in autism and to investigate whether the H4 ligand JNJ7777120 can enhance DNA repair efficiency in BTBR T+tf/J (BTBR) mice; we also attempted to elucidate the mechanism(s) underlying this amelioration. Evaluation of DNA damage using the comet assay on bone marrow cells showed increased levels of DNA damage in BTBR mice compared with age-matched control C57BL/6J mice. Conversely, BTBR animals pretreated with 20 mg/kg JNJ7777120 for five days exhibited significant decreases in DNA damage compared with that of control BTBR mice. Our results also indicated higher sensitivity of BTBR mice exposed to gamma rays to DNA damage generation. A marked difference was observed between BTBR and C57BL/6J mice at different sampling times after irradiation, with BTBR mice showing a higher percentage of DNA damage and slower repair rate than that of C57BL/6J mice. JNJ7777120 led to enhanced repair of the DNA damage induced by radiation when administered to BTBR mice five days prior to radiation. Additionally, oxidative stress in BTBR mice was significantly elevated with a reduced GSH/GSSG ratio; significant amelioration was subsequently observed in JNJ7777120-pretreated BTBR mice. Furthermore, repetitive behaviors were also attenuated in BTBR mice by JNJ7777120 treatment without altering locomotor activity. Our results suggest that JNJ7777120 can be developed for use as a therapeutic agent to enhance DNA repair efficiency in autism spectrum disorder.


Assuntos
Transtorno do Espectro Autista/genética , Reparo do DNA , Indóis/farmacologia , Piperazinas/farmacologia , Animais , Transtorno do Espectro Autista/metabolismo , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/efeitos da radiação , Modelos Animais de Doenças , Raios gama , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação
8.
J Fr Ophtalmol ; 42(4): e133-e146, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30850197

RESUMO

Behçet's disease is a chronic multisystem disorder characterized by relapsing inflammation for which the underlying histopathology is an occlusive vasculitis. The disease has a high prevalence in the Mediterranean region, Far and Middle Eastern countries. It is clinically characterized by oral and genital ulcerations, ocular inflammatory involvement, skin lesions, vascular involvement and numerous other systemic manifestations. Uveitis is by far the most common ocular manifestation of Behçet's disease. It typically presents in the form of relapsing-remitting panuveitis with retinal vasculitis that may result in severe visual loss. Management of Behçet's uveitis relies on corticosteroid therapy, conventional immunosuppressive drugs and biological agents and requires a close collaboration between ophthalmologist and internist. A better understanding of auto-inflammatory process and of the role of cytokines implicated in the pathogenesis of Behçet's disease will enable researchers to develop more specific and effective therapy.


Assuntos
Síndrome de Behçet/complicações , Síndrome de Behçet/fisiopatologia , Olho/fisiopatologia , Fenômenos Fisiológicos Oculares , Síndrome de Behçet/tratamento farmacológico , Síndrome de Behçet/epidemiologia , Produtos Biológicos/uso terapêutico , Olho/efeitos dos fármacos , Olho/patologia , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Inflamação/complicações , Inflamação/tratamento farmacológico , Inflamação/epidemiologia , Vasculite Retiniana/tratamento farmacológico , Vasculite Retiniana/epidemiologia , Vasculite Retiniana/etiologia , Uveíte/tratamento farmacológico , Uveíte/epidemiologia , Uveíte/etiologia , Uveíte/fisiopatologia , Transtornos da Visão/tratamento farmacológico , Transtornos da Visão/epidemiologia , Transtornos da Visão/etiologia
9.
Toxicol Appl Pharmacol ; 350: 43-51, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29733868

RESUMO

Histone deacetylases (HDACs), which regulate transcription and specific functions such as tumor suppression by p53, are frequently altered in tumors and have a contentious role in carcinogenesis. HDAC inhibitors, which have a long history of use in psychiatry and neurology, have recently been tested as possible treatments for tumors. Belinostat received regulatory approval in the USA on July 3, 2014, for use against peripheral T-cell lymphoma. However, the unavailability of information on belinostat genotoxicity in normal cells and the molecular mechanisms involved in the genetic instability after exposure to belinostat encouraged us to conduct this study. Our data showed that the exposure of mice to belinostat at the recommended human doses induced chromosome breakage, whole-chromosome lagging, and oxidative DNA damage in bone marrow cells in a dose-dependent manner. The expression levels of 84 genes involved in the DNA damage signaling pathway were evaluated by using an RT2 Profiler PCR array. Belinostat exposure altered the expression of 25 genes, with statistically significant changes observed in 17 genes. The array results were supported by RT-PCR and western blotting experiments. Collectively, our results showed that belinostat exposure caused oxidative DNA damage and downregulated the expression of genes involved in DNA damage repair, which may be responsible for belinostat-induced genomic instability. Thus, the clinical usage of this drug should be weighed against the hazards of carcinogenesis, and the observed genotoxicity profile of belinostat may support further development of efficient HDAC inhibitors with weaker genotoxicity.


Assuntos
Análise Citogenética/métodos , Perfilação da Expressão Gênica/métodos , Instabilidade Genômica/efeitos dos fármacos , Inibidores de Histona Desacetilases/toxicidade , Ácidos Hidroxâmicos/toxicidade , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/toxicidade , Animais , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Relação Dose-Resposta a Droga , Instabilidade Genômica/fisiologia , Masculino , Camundongos , Transdução de Sinais/fisiologia
10.
Reprod Domest Anim ; 51(1): 54-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26660630

RESUMO

Good-quality semen is a prerequisite for successful and profitable artificial insemination (AI) of modern dairy cattle. Fertility of the bulls is evaluated with andrological examinations and semen analyses, such as morphology. However, little attention has been paid to the inheritance of bull fertility. In this study, we correlated sperm morphology, birth year and station of 695 AI bulls with calving rate (CR). Sperm morphology was clearly associated with CR underlining the usefulness of morphological examination in the assessment of fertility. The correlation between the proportion of normal spermatozoa and CR was significant (p < 0.001). No significant differences were detected between stations or birth years. We also compared the CR of 695 AI bulls with the CR of their 27 sires to study the inheritance of fertility. Sire's CR did not correlate with the CR of the sons (p = 0.218). This result indicates that at least when sires of acceptable CR are used to produce sons for use in AI the inheritance of CR is not significantly correlated.


Assuntos
Cruzamento/métodos , Bovinos , Fertilidade/genética , Inseminação Artificial/veterinária , Espermatozoides/citologia , Animais , Coeficiente de Natalidade , Bovinos/genética , Bovinos/fisiologia , Feminino , Finlândia , Masculino , Gravidez , Espermatozoides/anormalidades
11.
Cancer Chemother Pharmacol ; 77(1): 27-33, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26645402

RESUMO

PURPOSE: Despite dexrazoxane's increasing use in mitigating doxorubicin-induced cardiotoxicity, no data are available in the literature on the potential aneugenicity of drug combination. Therefore, detailed evaluation of aneugenic potential of this combination is essential to provide more insights into aneuploidy induction that may play a role in the development of secondary malignancies and reproductive toxicity after treatment with doxorubicin. Thus, our aim was to determine whether dexrazoxane has influence on the aneuploidy induced by doxorubicin in germinal and somatic cells of male mice. METHODS: Sperm BrdU-incorporation assay, sperm FISH assay and the bone marrow micronucleus test complemented by FISH assay were used to determine aneuoploidy. Moreover, the formation of 8-OHdG, one of the oxidative DNA damage by-products, has been evaluated. RESULTS: Dexrazoxane was not aneugenic at the doses tested. Pre-treatment of mice with dexrazoxane significantly reduced doxorubicin-induced aneuploidy in a dose-dependent manner. Doxorubicin induced marked biochemical alterations characteristic of oxidative DNA damage, and prior administration of dexrazoxane before doxorubicin challenge ameliorated this biochemical marker. CONCLUSION: This study provides evidence that dexrazoxane has a protective role in the abatement of doxorubicin-induced aneuploidy. This activity resides, at least in part, in its radical scavenger activity. Thus, dexrazoxane can avert secondary malignancies and abnormal reproductive outcomes in cured cancer patients exposed to doxorubicin.


Assuntos
Aneuploidia , Dexrazoxano/farmacologia , Doxorrubicina/toxicidade , Espermatozoides/citologia , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/toxicidade , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Dexrazoxano/administração & dosagem , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Hibridização in Situ Fluorescente/métodos , Masculino , Camundongos , Testes para Micronúcleos , Espermatozoides/efeitos dos fármacos
12.
Artigo em Inglês | MEDLINE | ID: mdl-25945256

RESUMO

UNLABELLED: 3-M syndrome is a rare autosomal recessive disorder caused by mutations in the CUL7, OBSL1 and CCDC8 genes. It is characterised by growth failure, dysmorphic features and skeletal abnormalities. Data in the literature show variable efficacy of GH in the treatment of short stature. We report four Emirati siblings with the condition. The index case is a 10-year-old boy with characteristic features, including prenatal and postnatal growth failure, a triangular face, a long philtrum, full lips and prominent heels. Genetic testing confirmed a novel mutation (p.val88Ala) in the CUL7 gene. The parents are healthy, first-degree cousins with nine children, of whom two died in the first year of life with respiratory failure. Both had low birth weight and growth retardation. The boy's older sibling reached an adult height of 117 cm (-6.71 SDS). She was never treated with GH. He was started on GH treatment at 7 years of age, when his height was 94 cm (-5.3 SDS). 3-M syndrome should be considered in children with short stature who have associated dysmorphism and skeletal abnormalities. The diagnosis is more likely to occur in families that have a history of consanguinity and more than one affected sibling. Death in early infancy due to respiratory failure is another clue to the diagnosis, which might have a variable phenotype within a family. Genetic testing is important for confirming the diagnosis and for genetic counselling. GH treatment might be beneficial in improving stature in affected children. LEARNING POINTS: 3-M syndrome should be considered in families that have more than one sibling with short stature, particularly if there is consanguinity.Syndrome phenotype might be variable within a family with the same mutation.Genetic analysis is helpful in confirming diagnosis in the presence of variable siblings' phenotype.GH treatment might be useful in improving stature in 3-M syndrome.

13.
Food Chem Toxicol ; 77: 101-4, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25595372

RESUMO

The ability of the anticancer drug, nocodazole, to induce dominant lethal mutations in male germ cells was investigated by the in vivo dominant lethal test. Mice were treated with single doses of 15, 30 and 60 mg/kg nocodazole. These males were mated at weekly intervals to virgin females for 6 weeks. Nocodazole clearly induced dominant lethal mutations in the early spermatid stage with the highest tested dose. Mice treated with 60 mg/kg nocodazole showed an additional peak of dominant lethal induction in mature spermatozoa during the first week matings after treatment. The percentage sperm count and sperm motility were significantly decreased after treatment of males with 30 and 60 mg/kg nocodazole. Moreover, the middle and highest doses of nocodazole significantly increased the percentage of abnormal sperm. Our study provides evidence that nocodazole is a germ cell mutagen. Marked alteration in the spermiogram analysis after nocodazole treatment possibly confirms that nocodazole has a significant effect on sperm maturation and development during storage and transit. The demonstrated mutagenicity profile of nocodazole may support further development of effective chemotherapy with less mutagenicity. Moreover, the cancer patients and medical personnel exposed to this drug chemotherapy may stand a higher risk for abnormal reproductive outcomes.


Assuntos
Antineoplásicos/efeitos adversos , Mutação , Nocodazol/efeitos adversos , Espermatozoides/efeitos dos fármacos , Animais , Antineoplásicos/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Genes Dominantes , Masculino , Camundongos , Testes de Mutagenicidade , Nocodazol/administração & dosagem , Reprodução/efeitos dos fármacos , Contagem de Espermatozoides , Motilidade dos Espermatozoides/efeitos dos fármacos
15.
Eye (Lond) ; 28(8): 986-91, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24924439

RESUMO

PURPOSE: To investigate the prevalence and causes of blindness and partial sight among a population of Tunisian diabetic patients. METHODS: A cross-sectional study of 2320 randomly identified patients with diabetes mellitus. Patient's characteristics as well as data from the last ophthalmic examination were reviewed. RESULTS: Of all patients examined, 60.2% were females and 39.8% were males. Mean age of patients was 54.5 years. Mean duration of diabetes was 7.6 years. Diabetic retinopathy (DR) was recorded in 26.3% of patients, and was proliferative in 3.4% of patients. The prevalence of visual impairment was 22.2%, with 4.4% patients legally blind and 17.8% partially sighted. Visual impairment was significantly associated with age ≥60 years (P<0.001), duration of diabetes >10 years (P<0.001), body mass index >25 (P=0.014), hypertension (P<0.001), heart disease (P<0.001), peripheral neuropathy (P=0.03), vegetative neuropathy (P=0.002), macroalbuminuria (P<0.001), cataract (P<0.001), DR (P<0.001), diabetic macular edema (P<0.001), open angle glaucoma (P<0.001), intravitreal hemorrhage (P<0.001), rubeosis iridis (P<0.001), neovascular glaucoma (P<0.001), and tractional retinal detachment (P<0.001). CONCLUSION: The current report is the largest study of DR in North African region. It provides a baseline data against which future progress can be assessed. Screening and treatment can greatly reduce the incidence of visual impairment due to diabetes.


Assuntos
Cegueira/epidemiologia , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Baixa Visão/epidemiologia , Pessoas com Deficiência Visual/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cegueira/etiologia , Glicemia/metabolismo , Constituição Corporal , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Tunísia/epidemiologia , Baixa Visão/etiologia
16.
Mutagenesis ; 29(1): 55-62, 2014 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-24342934

RESUMO

Although chloroacetonitrile (CAN), a disinfection by-product of chlorination of drinking water, is considered a rodent carcinogen that induces lung adenomas in mice, previous studies on its genotoxicity have yielded inconclusive results. Thus, its cancer mode of action has not been clearly defined. We evaluated CAN-induced genotoxicity in mice using mouse bone marrow micronucleus test, comet assays and expression of genes associated with DNA damage repair. Mice exposed to CAN at 8.75, 17.5, 35 and 52.5mg/kg for 7 days did not exhibit any significant increases in the incidence of micronuclei formation at 24 and 48h after last exposure. However, CAN caused significant suppressions of erythroblast proliferation at the highest dose. In the alkaline comet assay, there was a significant increase in the incidence of DNA strand breaks in mice killed after 3h of last treatment with 35 and 52.5mg/kg/day CAN, while no significant difference in the DNA strand breaks was found in mice killed after 24h of the last treatment. However, slight (but significant) CAN-induced oxidative DNA damage was detected following Fpg digestion at 3-h sampling time, digestion with EndoIII resulted in considerable increases in oxidative DNA damage at 3 and 24h after the last exposure to 35 and 52.5mg/kg/day CAN as detected by oxidative comet assays. The expression of DNA repair genes OGG1 , Apex1, PARP1 and p53 were up-regulated in mice given 35mg/kg/day CAN at 3h but not in 24h after the last treatment except OGG1 . However, the significant up-regulation of OGG1 at 24h after the last treatment further indicates the occurrence of oxidative DNA damage. Overall, CAN exposure is associated with up-regulation of DNA repair gene expression and the induction of oxidative DNA damage, which may be at least partially responsible for CAN-induced genotoxicity and eventually cause carcinogenicity.

18.
Food Chem Toxicol ; 62: 470-4, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24036143

RESUMO

To investigate the ability of topotecan, a topoisomerase I-targeting anticancer drug, to induce dominant lethal mutations in male mouse germ cells, males were treated with single doses of 3, 6 and 12 mg/kg topotecan. Each male was mated at 4-day intervals to virgin females for a total of nine 4-day mating intervals. The two highest doses of topotecan are shown to be mutagenic in post-meiotic cells. The greatest effect occurred in those cells which were in the early-spermatid stage at the time of exposure. Mice treated with 12 mg/kg topotecan showed an additional peak of dominant lethal induction in mature sperm during the first 4-day matings after treatment. The mutagenic effects were directly correlated with free radicals accumulation as an obvious increase in the generation reactive oxygen species and 8-hydroxydeoxyguanosine was noted in animals treated with 6 and 12 mg/kg topotecan. Treatment of male mice with N-acetylcysteine, a free radical scavenger, significantly protected mice from topotecan-induce dominant lethality. Moreover, N-acetylcysteine had no antagonizing effect on topotecan-induce topoisomerase-I inhibition. Our study provides evidence that topotecan is a germ cell mutagen and its effect is more pronounced during the post-meiotic stages through a mechanism that may involves increases in DNA oxidative stress.


Assuntos
Mutagênicos/toxicidade , Espermatozoides/efeitos dos fármacos , Inibidores da Topoisomerase I/toxicidade , Topotecan/toxicidade , 8-Hidroxi-2'-Desoxiguanosina , Acetilcisteína/farmacologia , Animais , Antineoplásicos/toxicidade , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Relação Dose-Resposta a Droga , Feminino , Sequestradores de Radicais Livres/farmacologia , Masculino , Camundongos , Testes de Mutagenicidade , Gravidez , Espécies Reativas de Oxigênio/metabolismo
19.
J Econ Entomol ; 104(4): 1220-8, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21882686

RESUMO

The essential oil of Deverra scoparia Coss. & Durieu was investigated for its acaricidal activity against the worldwide pest twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). The essential oil was analyzed by fast gas chromatography (GC) and GC-mass spectrometry. The activities of its individual and blended constituents were determined. Our study showed that female mortality increased with increasing D. scoparia oil concentrations, with LD50 and LD90 values at 1.79 and 3.2 mg liter(-1), respectively. A reduction in fecundity had already been observed for concentrations of 0.064, 0.08, and 0.26 mg liter(-1) D. scoparia essential oil. Ten major components, comprising 98.52% of the total weight, were identified; a-pinene was the most abundant constituent (31.95%) followed by sabinene (17.24%) and delta3-carene (16.85%). The 10 major constituents of D. scoparia oil were individually tested against T. urticae females. The most potent toxicity was found with alpha-pinene, delta3-carene, and terpinen-4-ol. The presence of all constituents together in the artificial mixture caused a significant decrease in the number of eggs laid by females, at 0.26 mg liter(-1) (11 eggs), compared with the control (50 eggs). The toxicity of blends of selected constituents indicated that the presence of all constituents was necessary to reproduce the toxicity level of the natural oil.


Assuntos
Acaricidas/isolamento & purificação , Apiaceae/química , Óleos Voláteis/química , Tetranychidae , Animais , Feminino , Fertilidade/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/farmacologia , Tetranychidae/efeitos dos fármacos
20.
Mutagenesis ; 26(4): 533-43, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21430063

RESUMO

The intention of the present study was to answer the question whether the catalytic topoisomerase-II inhibitor, dexrazoxane, can be used as a modulator of teniposide-induced DNA damage and programmed cell death (apoptosis) in the bone marrow cells in vivo. The alkaline single cell gel electrophoresis, scoring of chromosomal aberrations, micronuclei and mitotic activity were undertaken in the current study as markers of DNA damage. Apoptosis was analysed by the occurrence of a hypodiploid DNA peak and caspase-3 activity. Oxidative stress marker such as intracellular reactive oxygen species production, lipid peroxidation, reduced and oxidised glutathione were assessed in bone marrow as a possible mechanism underlying this amelioration. Dexrazoxane was neither genotoxic nor apoptogenic in mice at the tested dose. Moreover, for the first time, it has been shown that dexrazoxane affords significant protection against teniposide-induced DNA damage and apoptosis in the bone marrow cells in vivo and effectively suppresses the apoptotic signalling triggered by teniposide. Teniposide induced marked biochemical alterations characteristic of oxidative stress including accumulation of intracellular reactive oxygen species, enhanced lipid peroxidation, accumulation of oxidised glutathione and reduction in the reduced glutathione level. Prior administration of dexrazoxane ahead of teniposide challenge ameliorated these biochemical alterations. It is thus concluded that pretreatment with dexrazoxane attenuates teniposide-induced oxidative stress and subsequent DNA damage and apoptosis in bone marrow cells. Based on our data presented, strategies can be developed to decrease the teniposide-induced DNA damage in normal cells using dexrazoxane. Therefore, dexrazoxane can be a good candidate to decrease the deleterious effects of teniposide in the bone marrow cells of cancer patients treated with teniposide.


Assuntos
Apoptose/efeitos dos fármacos , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Dano ao DNA , Razoxano/farmacologia , Teniposídeo/toxicidade , Animais , Células da Medula Óssea/enzimologia , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Cromossomos de Mamíferos/metabolismo , Quebras de DNA/efeitos dos fármacos , Citometria de Fluxo , Glutationa/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
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