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2.
Indian J Pathol Microbiol ; 64(4): 702-706, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34673589

RESUMO

INTRODUCTION: Synovium has been documented as a primary site of inflammation and a major effector organ in a variety of joint diseases. Study of simple technique like synovial biopsy can help in early diagnosis and treatment of diseases significantly improving outcome of patient in cases of rheumatoid arthritis, osteoarthritis, etc., Only limited data exist on utility of synovial biopsies. AIM AND OBJECTIVES: To analyze the pattern of synovial lesions to differentiate between different kinds of arthritis. Also, to identify early stages of arthritis so as to prevent unnecessary invasive surgical procedure. MATERIALS AND METHODS: It's a retrospective study to analyze 103 cases of synovial lesions diagnosed in last five years at a tertiary care orthopedic center. All synovial biopsies obtained mainly by open method and few by arthroscopic method, that came to the Dept of Pathology were included. Lesions were classified into four categories that is, inflammatory joint diseases, degenerative joint diseases, tumor-like conditions and tumors. RESULTS: Age group most affected was between 61 and 70 years, with male predominance. Osteoarthritis (OA) was the most common histopathological diagnosis. Early OA tissues showed greater lining layer thickness, vessel proliferation, and inflammation, while surface fibrin deposition along with fibrosis was noted in later stages. CONCLUSION: The histo-morphological observations made in this study may have important therapeutic implications for some patients during the early evolution of arthritis and could prevent unnecessary operative intervention of later stages.


Assuntos
Biópsia/estatística & dados numéricos , Artropatias/diagnóstico , Artropatias/fisiopatologia , Membrana Sinovial/fisiopatologia , Centros de Atenção Terciária/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
3.
J Orthop Surg (Hong Kong) ; 29(1): 23094990211001621, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33779373

RESUMO

PURPOSE: The aim of this study was to assess the effects of the COVID-19 pandemic on anxiety, sleep outcomes and change in clinical management practices among orthopaedic surgeons following a nation-wide lockdown. METHODS: We conducted an online cross-sectional study using piloted structured questionnaires with self-reported responses from Indian orthopaedic surgeons. Study participants were identified through social networking sites: Facebook and WhatsApp. The extent of anxiety and sleep quality was assessed by the standardised seven-item Generalised Anxiety Disorder (GAD-7) scale, single-item sleep quality scale, questions on unavailability of personal protective equipment, training module on COVID-19 and change in orthopaedic patient management. RESULTS: One hundred male orthopaedic surgeons responded to the survey with majority (79%) in 30-44 years age group. Severe anxiety scores were observed in 8%; moderate, mild and minimal anxiety was observed in 12%, 27% and 53% surgeons respectively. Changes in management practice due to the pandemic was admitted by 65% respondents. We also observed an association between higher anxiety among surgeons and primary or secondary level of healthcare facility: (p = 0.04). Sleep disturbance was significantly associated with change in management practice to non-operative procedures (p = 0.03). CONCLUSION: Anxiety among orthopaedic surgeons during the COVID-19 pandemic is related to factors like younger age group, working in a primary or secondary healthcare facility. Early recognition of anxiety is essential to prevent serious psychological sequelae.


Assuntos
Ansiedade/etiologia , COVID-19/complicações , Cirurgiões Ortopédicos/estatística & dados numéricos , Pandemias , Sono/fisiologia , Adulto , Ansiedade/epidemiologia , COVID-19/epidemiologia , Comorbidade , Estudos Transversais , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Inquéritos e Questionários
4.
Spine Deform ; 8(4): 677-684, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32162198

RESUMO

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The purpose was to analyze the effect of care bundle protocol on SSI in our institution. Postoperative surgical site infections (SSI) pose significant health burden. In spite of the use of prophylactic antibiotics, surgical advances and postoperative care, wound infection continues to affect patient outcomes after spine surgery. METHODS: Retrospective analysis of 9607 consecutive patients who underwent spine procedures from 2014 to 2018 was performed. Preventive care bundle was implemented from January 2017 consisting of (a) preoperative bundle-glycemic control, chlorhexidine gluconate (CHG) bath, (b) intra-operative bundle-time specified antibiotic prophylaxis, CHG+ alcohol-based skin preparation (c) postoperative bundle-five moments of hand hygiene, early mobilization and bundle auditing. Patients operated from January 2017 were included in the post-implementation cohort and prior to that the pre-implementation cohort was formed. Data were drawn from weekly and yearly spine audits from the hospital infection committee software. Infection data were collected based on CDC criteria, further sub classification was done based on procedure, spinal disorders and spine level. Variables were analyzed and level of significance was set as < 0.05. RESULTS: A total of 7333 patients met the criteria. The overall SSI rate decreased from 3.42% (131/3829) in pre-implementation cohort to 1.22% (43/3504, p = 0.0001) in post-implementation cohort (RR = 2.73, OR = 2.79). Statistically significant reduction was seen in all the groups (a) superficial and deep, (b) early and late and (c) instrumented and uninstrumented groups but was more pronounced in early (p = 0.0001), superficial (p = 0.0001) and instrumented groups (p = 0.0001). On subgroup analysis based on spine level and spinal disorders, significant reduction was seen in lumbar (p = 0.0001) and degenerative group (p = 0.0001). CONCLUSIONS: Our study revealed significant reduction of SSI secondary to strict bundle adherence and monitored compliance compared to patients who did not receive these interventions. LEVEL OF EVIDENCE: III.


Assuntos
Pacotes de Assistência ao Paciente/métodos , Doenças da Coluna Vertebral/cirurgia , Coluna Vertebral/cirurgia , Infecção da Ferida Cirúrgica/prevenção & controle , Adulto , Idoso , Antibioticoprofilaxia , Banhos , Clorexidina/análogos & derivados , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Controle de Infecções/métodos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Estudos Retrospectivos , Adulto Jovem
5.
Asian Spine J ; 14(1): 43-50, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31608610

RESUMO

STUDY DESIGN: Prospective study. PURPOSE: During the last decades, an emergence of unplanned readmissions has been shown to be a useful tool to gage the healthcare quality and hospital performance. Previous studies were limited by their retrospective designs based on database information and short-term 30-day follow-up intervals. We analyzed the incidence and causes for unplanned readmissions following spine surgery at a 90-day interval and the difference at 30-, 31-60-, and 61-90-day intervals after discharge. Additionally, we assessed total beddays lost and the economic impact of readmissions and probable risk factors. OVERVIEW OF LITERATURE: Recent reports on readmission rates suggested the contribution of this parameter for the assessment of healthcare quality. METHODS: A prospective analysis of 2,860 admissions was performed over 1 year in a tertiary care orthopedic hospital. All unscheduled readmissions following spine surgery within 90 days of discharge were included, irrespective of type or location of surgery. Polytrauma, primary osseous infections, and planned readmissions were excluded. RESULTS: Our readmission rate was 3.32% (95/2,860). Leading readmission causes were surgical site infections (SSIs) accounting for 44.21% (n=42; superficial, 23; deep, 11; organ and space, 8), followed by aseptic pain 31.58% (n=30) and medical causes 13.68% (n=13). Though 86.95% of superficial SSIs occurred within 30 days, 21.1% of deep SSIs occurred beyond 30 days. During the 30-90-day interval, 33.68% of readmissions occurred. The financial burden amounted to 41,93,660 Indian Rupees, and the mean bed-days lost was 7.33 per readmission. Hospital stay ≥10 days, health insurance, and comorbid illnesses (diabetes, hypertension, and liver disease) were associated with readmissions (p<0.05). CONCLUSIONS: Our study showed that SSIs and aseptic pain were the leading causes of readmissions at 90 days after spine surgery. Limiting the analysis to 30-day readmissions as in previous studies would lead to failure in the identification of more severe complications like deep SSIs. Continued vigilance, particularly for patients with predisposing factors, could help alleviate the financial burden.

6.
Methods Mol Biol ; 2031: 301-311, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31473967

RESUMO

DNA is one of the most biologically important targets of exogenous and endogenous toxicants as well as carcinogens. Damage to DNA can be of different types (e.g., DNA adducts, DNA protein cross-links, single-strand breaks, oxidized bases, abasic sites, and double-strand breaks (DSBs)). DSBs are considered the most lethal form of DNA damage for eukaryotic cells, and if left unrepaired or misrepaired, can cause cell death, chromosome instability, and cancer. DSBs can arise in the cells through different sources and can be distinguished as endogenous or exogenous DSBs. Exogenous sources can be chemotherapeutic drugs, irradiation, and environmental chemicals. The endogenous causes of DNA DSBs in the cells are mainly reactive oxygen species and faulty repair of oxidative clustered DNA lesions. Qualitative and quantitative analysis of DNA DSBs is of utmost importance to understand physiologically relevant cellular processes as well as to investigate the genotoxic or clastogenic effects of toxicants. Pulsed-field gel electrophoresis (PFGE) is a widely used method for direct quantification of DNA DSBs. In this method, the cells exposed to DSB-inducing agents are embedded in the agarose blocks and lysed. These agarose blocks containing DNA are then run under multiple electric fields which are at 120° angle, to aid in the movement of large DNA strands. It gives a direct and specific measure of DSBs unlike the foci-based assays. This chapter provides a brief overview of the various commonly used approaches to analyze DNA DSBs and describes the theory, advantages and method of PFGE, for use in cells exposed to DNA DSB inducing agents.


Assuntos
Quebras de DNA de Cadeia Dupla , Eletroforese em Gel de Campo Pulsado/métodos , Linhagem Celular , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Humanos , Testes de Mutagenicidade/métodos , Mutagênicos/toxicidade , Coloração e Rotulagem/métodos
7.
J Nanosci Nanotechnol ; 18(1): 544-555, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29768880

RESUMO

Little is known of the effects of nanoparticles in human systems, let alone in diseased individuals and nanotechnology has preceded nanotoxicology. Therefore, the effects of titanium dioxide (TiO2) nanoparticles in peripheral blood lymphocytes from patients with respiratory diseases [lung cancer, chronic obstructive pulmonary disease (COPD) and asthma] were compared with those in healthy Individuals, to determine differences in sensitivity to nanochemical insult. The Comet assay was performed according to recommended guidelines. The micronucleus assay and ras oncoprotein detection were conducted according to published standard methods. The results showed statistically significant concentration-dependent genotoxic effects of TiO2 NPs in both respiratory patient and control groups in the Comet assay. The TiO2 NPs caused DNA damage in a concentration dependent manner in both groups (respiratory and healthy controls) with the exception of the lowest TiO2 concentration (10 µg/ml) which did not induce significant damage in healthy controls (n.s). When OTM data were used to compare the whole patient group and the control group, the patient group had more DNA damage (p > 0.001) with the exception of 10 µg/ml of TiO2 that caused less significant damage to patient lymphocytes (p < 0.05). Similarly, there was an increase in the pattern of cytogenetic damage measured in the MN assay without statistical significance except when compared to the negative control of healthy individuals. Furthermore, when modulation of ras p21 expression was investigated, regardless of TiO2 treatment, only lung cancer and COPD patients expressed measurable ras p21 levels. Results were achieved in the absence of cytotoxicity.


Assuntos
Dano ao DNA , Nanopartículas Metálicas , Nanopartículas , Titânio , Ensaio Cometa , Humanos , Linfócitos , Titânio/toxicidade
8.
Sci Rep ; 7(1): 10787, 2017 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-28883613

RESUMO

Endogenous formaldehyde is abundantly present in our bodies, at around 100 µM under normal conditions. While such high steady state levels of formaldehyde may be derived by enzymatic reactions including oxidative demethylation/deamination and myeloperoxidation, it is unclear whether endogenous formaldehyde can initiate and/or promote diseases in humans. Here, we show that fluorescent malondialdehyde-formaldehyde (M2FA)-lysine adducts are immunogenic without adjuvants in mice. Natural antibody titers against M2FA are elevated in atherosclerosis-prone mice. Staining with an antibody against M2FA demonstrated that M2FA is present in plaque found on the aortic valve of ApoE -/- mice. To mimic inflammation during atherogenesis, human myeloperoxidase was incubated with glycine, H2O2, malondialdehyde, and a lysine analog in PBS at a physiological temperature, which resulted in M2FA generation. These results strongly suggest that the 1,4-dihydropyridine-type of lysine adducts observed in atherosclerosis lesions are likely produced by endogenous formaldehyde and malondialdehyde with lysine. These highly fluorescent M2FA adducts may play important roles in human inflammatory and degenerative diseases.


Assuntos
Aterosclerose/imunologia , Aterosclerose/metabolismo , Epitopos/imunologia , Formaldeído/metabolismo , Animais , Apolipoproteínas E/deficiência , Cromatografia Líquida , Formaldeído/química , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Camundongos , Camundongos Knockout , Estrutura Molecular , Peroxidase/metabolismo , Placa Aterosclerótica/imunologia , Placa Aterosclerótica/metabolismo
9.
Oncotarget ; 7(37): 59795-59808, 2016 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-27486975

RESUMO

Isopropyl methanesulfonate (IPMS) is the most potent genotoxic compound among methanesulfonic acid esters. The genotoxic potential of alkyl sulfonate esters is believed to be due to their alkylating ability of the O6 position of guanine. Understanding the primary repair pathway activated in response to IPMS-induced DNA damage is important to profile the genotoxic potential of IPMS. In the present study, both chicken DT40 and human TK6 cell-based DNA damage response (DDR) assays revealed that dysfunction of the FANC pathway resulted in higher sensitivity to IPMS compared to EMS or MMS. O6-alkyl dG is primarily repaired by methyl guanine methyltransferase (MGMT), while isopropyl dG is less likely to be a substrate for MGMT. Comparison of the cytotoxic potential of IPMS and its isomer n-propyl methanesulfonate (nPMS) revealed that the isopropyl moiety avoids recognition by MGMT and leads to higher cytotoxicity. Next, the micronucleus (MN) assay showed that FANC deficiency increases the sensitivity of DT40 cells to MN induction by IPMS. Pretreatment with O6-benzyl guanine (OBG), an inhibitor of MGMT, increased the MN frequency in DT40 cells treated with nPMS, but not IPMS. Lastly, IPMS induced more double strand breaks in FANC-deficient cells compared to wild-type cells in a time-dependent manner. All together, these results suggest that IPMS-derived O6-isopropyl dG escapes recognition by MGMT, and the unrepaired DNA damage leads to double strand breaks, resulting in MN induction. FANC, therefore, plays a pivotal role in preventing MN induction and cell death caused by IPMS.


Assuntos
Linfócitos B/fisiologia , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Grupos de Complementação da Anemia de Fanconi/metabolismo , Anemia de Fanconi/genética , Guanina/metabolismo , Mesilatos/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Proteínas Supressoras de Tumor/metabolismo , Animais , Linfócitos B/efeitos dos fármacos , Morte Celular , Linhagem Celular , Galinhas , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Dano ao DNA , Metilases de Modificação do DNA/antagonistas & inibidores , Reparo do DNA , Enzimas Reparadoras do DNA/antagonistas & inibidores , Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Guanina/análogos & derivados , Guanina/farmacologia , Humanos , RNA Interferente Pequeno/genética , Transdução de Sinais , Proteínas Supressoras de Tumor/antagonistas & inibidores
10.
Oncotarget ; 7(18): 25377-90, 2016 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-27015367

RESUMO

DNA damage and mutations induced by oxidative stress are associated with various different human pathologies including cancer. The facts that most human tumors are characterized by large genome rearrangements and glutathione depletion in mice results in deletions in DNA suggest that reactive oxygen species (ROS) may cause gene and chromosome mutations through DNA double strand breaks (DSBs). However, the generation of DSBs at low levels of ROS is still controversial. In the present study, we show that H2O2 at biologically-relevant levels causes a marked increase in oxidative clustered DNA lesions (OCDLs) with a significant elevation of replication-independent DSBs. Although it is frequently reported that OCDLs are fingerprint of high-energy IR, our results indicate for the first time that H2O2, even at low levels, can also cause OCDLs leading to DSBs specifically in G1 cells. Furthermore, a reverse genetic approach revealed a significant contribution of the non-homologous end joining (NHEJ) pathway in H2O2-induced DNA repair & mutagenesis. This genomic instability induced by low levels of ROS may be involved in spontaneous mutagenesis and the etiology of a wide variety of human diseases like chronic inflammation-related disorders, carcinogenesis, neuro-degeneration and aging.


Assuntos
Dano ao DNA/fisiologia , Reparo do DNA por Junção de Extremidades/fisiologia , Mutagênese/fisiologia , Estresse Oxidativo/fisiologia , Animais , Linhagem Celular , Galinhas , Peróxido de Hidrogênio/toxicidade , Oxidantes/toxicidade
11.
Strategies Trauma Limb Reconstr ; 10(2): 79-85, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26216233

RESUMO

The aim of our study was to evaluate the shoulder function after clavicular hook plate fixation of acute acromioclavicular dislocations (Rockwood type III) in a population group consisting exclusively of high-demand military personnel. This prospective study was carried out at a tertiary care military orthopaedic centre during 2012-2013 using clavicular hook plate for management of acromioclavicular injuries without coracoclavicular ligament reconstruction in 33 patients. All patients underwent routine implant removal after 16 weeks. The functional outcome was assessed at 3, 6 and 12 months after hook plate removal and 2 years from the initial surgery using the Constant Murley and UCLA Scores. All the patients were male serving soldiers and had sustained acromioclavicular joint dislocation (Rockwood type III). Mean age of the patient group was 34.24 years (21-55 years). The mean follow-up period in this study was 23.5 months (20-26 months) after hook plate fixation and an average of 19.9 months (17-22 months) after hook plate removal. The average Constant Score at 3 months after hook plate removal was 60.3 as compared to 83.7 and 90.3 at 6 months and 1 year, respectively, and an average of 91.8 at the last follow-up that was approximately 2 years after initial surgery which was statistically significant (p value <0.05). The UCLA Score was an average of 15.27, 25.9 and 30.1 at 3, 6 months and 1 year, respectively, after removal of hook plate which improved further an average of 32.3 at the last follow-up, which was also statistically significant (p value <0.05). Clavicular hook plate fixation without coracoclavicular ligament reconstruction is a good option for acute acromioclavicular dislocations producing excellent medium-term functional results in high-demand soldiers.

12.
Chem Res Toxicol ; 27(4): 480-2, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24628573

RESUMO

For DNA-reactive chemicals, a low dose linear assessment of cancer risk is the science policy default. In the present study, we quantitated the endogenous and exogenous N7-methyl-G and O(6)-methyl-dG adducts in human lymphoblastoid cells exposed to low dose [D3]-methylnitrosourea. Endogenous amounts of both adducts remained nearly constant, while the exogenous adducts showed linear dose-responses. The data show that O(6)-methyl-dG adducts ≥1.8/10(8) dG correlated with published studies that demonstrated significant increases of mutations under these conditions. The combined results do not support linear extrapolations to zero when data are available for science-based regulations.


Assuntos
Desoxiguanosina/análogos & derivados , Guanina/análogos & derivados , Metilnitrosoureia/farmacologia , Células Cultivadas , Desoxiguanosina/metabolismo , Relação Dose-Resposta a Droga , Guanina/metabolismo , Humanos , Metilnitrosoureia/administração & dosagem
13.
Methods Mol Biol ; 1028: 231-46, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23740124

RESUMO

The distinctive characteristics of engineered nanoparticles (ENPs) such as higher surface-to-volume ratio find immense applications in personal care products, food packaging, drug delivery systems, therapeutics & biosensors and others. The exponential increase in the ENP containing consumer products in the last 5 years has also increased their inadvertent release in the environment and a debate towards their adverse effects to the human and environment health. A variety of ENPs with different size, shape, and surface properties have been shown to induce genotoxicity, cytotoxicity, and oxidative stress in different cellular models. Here we describe the techniques and protocols used in the assessment of the genotoxicity (single-cell gel electrophoresis (comet) assay, cytokinesis block micronucleus assay) and oxidative stress parameters (reactive oxygen species, lipid peroxidation, and glutathione depletion) induced by the ENPs in the cells.


Assuntos
Dano ao DNA , Nanopartículas/toxicidade , Estresse Oxidativo , Células Cultivadas , Ensaio Cometa/métodos , Meios de Cultura , Glutationa/metabolismo , Humanos , Peroxidação de Lipídeos , Malondialdeído/metabolismo , Testes para Micronúcleos , Espécies Reativas de Oxigênio/metabolismo , Padrões de Referência , Análise de Célula Única/métodos , Espectrofotometria/normas
14.
Apoptosis ; 17(8): 852-70, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22395444

RESUMO

The wide scale use of Zinc oxide (ZnO) nanoparticles in the world consumer market makes human beings more prone to the exposure to ZnO nanoparticles and its adverse effects. The liver, which is the primary organ of metabolism, might act as a major target organ for ZnO nanoparticles after they gain entry into the body through any of the possible routes. Therefore, the aim of the present study was to assess the apoptotic and genotoxic potential of ZnO nanoparticles in human liver cells (HepG2) and the underlying molecular mechanism of its cellular toxicity. The role of dissolution in the toxicity of ZnO nanoparticles was also investigated. Our results demonstrate that HepG2 cells exposed to 14-20 µg/ml ZnO nanoparticles for 12 h showed a decrease in cell viability and the mode of cell death induced by ZnO nanoparticles was apoptosis. They also induced DNA damage which was mediated by oxidative stress as evidenced by an increase in Fpg sensitive sites. Reactive oxygen species triggered a decrease in mitochondria membrane potential and an increase in the ratio of Bax/Bcl2 leading to mitochondria mediated pathway involved in apoptosis. In addition, ZnO nanoparticles activated JNK, p38 and induced p53(Ser15) phosphorylation. However, apoptosis was found to be independent of JNK and p38 pathways. This study investigating the effects of ZnO nanoparticles in human liver cells has provided valuable insights into the mechanism of toxicity induced by ZnO nanoparticles.


Assuntos
Apoptose/efeitos dos fármacos , Dano ao DNA , Mitocôndrias Hepáticas/efeitos dos fármacos , Mutagênicos/toxicidade , Nanopartículas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Óxido de Zinco/farmacologia , Óxido de Zinco/toxicidade , Antioxidantes/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Células Hep G2 , Humanos , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos , Potencial da Membrana Mitocondrial , Mitocôndrias Hepáticas/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Nanopartículas/ultraestrutura , Oxirredução , Estresse Oxidativo , Tamanho da Partícula , Fosforilação , Processamento de Proteína Pós-Traducional , Óxido de Zinco/metabolismo
15.
J Biomed Nanotechnol ; 7(1): 108-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21485827

RESUMO

Carbon nanotubes (CNTs) are well known for their exceptional thermal, mechanical and electrical properties. For many CNT applications it is of the foremost importance to know their health hazards related to their exposure. Normal human bronchial epithelial cells (BEAS-2B) has been used for assessment the cytotoxicity of SWCNT (Diameter--1.2-1.5 nm) and DWCNT (Diameter--1.3-5 nm). Clear interference of CNTs with conventional in vitro cytotoxicity assays (MTT, NRU and LDH) dye was found which was confirmed by acellular system. However morphological changes and flow cytometry showed the characteristics of cytotoxicity. Thus our study showed that there is a need of appropriate method for the assessment of cytotoxicity of CNT.


Assuntos
Brônquios/citologia , Brônquios/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Teste de Materiais
16.
Toxicol In Vitro ; 25(1): 231-41, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21092754

RESUMO

Titanium dioxide nanoparticles (TiO(2) NPs) are among the top five NPs used in consumer products, paints and pharmaceutical preparations. Since, exposure to such nanoparticles is mainly through the skin and inhalation, the present study was conducted in the human epidermal cells (A431). A mild cytotoxic response of TiO(2) NPs was observed as evident by the MTT and NR uptake assays after 48 h of exposure. However, a statistically significant (p<0.05) induction in the DNA damage was observed by the Fpg-modified Comet assay in cells exposed to 0.8 µg/ml TiO(2) NPs (2.20±0.26 vs. control 1.24±0.04) and higher concentrations for 6 h. A significant (p<0.05) induction in micronucleus formation was also observed at the above concentration (14.67±1.20 vs. control 9.33±1.00). TiO(2) NPs elicited a significant (p<0.05) reduction in glutathione (15.76%) with a concomitant increase in lipid hydroperoxide (60.51%; p<0.05) and reactive oxygen species (ROS) generation (49.2%; p<0.05) after 6h exposure. Our data demonstrate that TiO(2) NPs have a mild cytotoxic potential. However, they induce ROS and oxidative stress leading to oxidative DNA damage and micronucleus formation, a probable mechanism of genotoxicity. This is perhaps the first study on human skin cells demonstrating the cytotoxic and genotoxic potential of TiO(2) NPs.


Assuntos
Epiderme/efeitos dos fármacos , Epiderme/metabolismo , Mutagênicos/toxicidade , Nanopartículas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Titânio/toxicidade , Transporte Biológico , Biomarcadores/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa/métodos , Qualidade de Produtos para o Consumidor , Dano ao DNA/efeitos dos fármacos , Epiderme/ultraestrutura , Glutationa/metabolismo , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Peróxidos Lipídicos/metabolismo , Testes para Micronúcleos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Nanopartículas/ultraestrutura , Tamanho da Partícula , Titânio/farmacocinética
17.
Toxicol Lett ; 185(3): 211-8, 2009 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-19382294

RESUMO

At present, more than 20 countries worldwide are manufacturing and marketing different varieties of nanotech-based consumer products of which cosmetics form the largest category. Due to the extremely small size of the nanoparticles (NPs) being used, there is a concern that they may interact directly with macromolecules such as DNA. The present study was aimed to assess the genotoxicity of zinc oxide (ZnO) NPs, one of the widely used ingredients of cosmetics, and other dermatological preparations in human epidermal cell line (A431). A reduction in cell viability as a function of both NP concentration as well as exposure time was observed. ZnO NPs demonstrated a DNA damaging potential as evident from an increased Olive tail moment (OTM) of 2.13 +/- 0.12 (0.8 g/ml) compared to control 1.37 +/- 0.12 in the Comet assay after an exposure of 6 h. ZnO NPs were also found to induce oxidative stress in cells indicated by depletion of glutathione (59% and 51%); catalase (64% and 55%) and superoxide dismutase (72% and 75%) at 0.8 and 0.08 g/ml respectively. Our data demonstrates that ZnO NPs even at low concentrations possess a genotoxic potential in human epidermal cells which may be mediated through lipid peroxidation and oxidative stress. Hence, caution should be taken in their use in dermatological preparations as well as while handling.


Assuntos
Dano ao DNA , Epiderme/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Mutagênicos/toxicidade , Nanopartículas , Óxido de Zinco/toxicidade , Catalase/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Células Epidérmicas , Epiderme/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Glutationa/metabolismo , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Microscopia Eletrônica de Transmissão , Mutagênicos/química , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Propriedades de Superfície , Óxido de Zinco/química
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