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1.
Malays Orthop J ; 15(3): 143-146, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34966511

RESUMO

The management of a patient with traumatic hemipelvectomy is complex. We report the acute management and rehabilitation of a 21-year-old patient as well as her prosthesis modification. She was able to return to society as a K3 level ambulator.

2.
Semin Cancer Biol ; 35 Suppl: S244-S275, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25865774

RESUMO

Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), ß-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-ß), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Caderinas/genética , Humanos , Invasividade Neoplásica/genética , Metástase Neoplásica , Neoplasias/patologia , Transdução de Sinais/efeitos dos fármacos , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/genética
3.
Oncogene ; 30(1): 117-26, 2011 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-20818437

RESUMO

Zinc has a crucial role in the biology of p53 in that p53 binds to DNA through a structurally complex domain stabilized by zinc atom. The p53 negative regulator MDM2 protein also carries a C-terminal RING domain that coordinates two zinc atoms, which are responsible for p53 nuclear export and proteasomal degradation. In this clinically translatable study, we explored the critical role of zinc on p53 reactivation by MDM2 inhibitor, MI-219, in colon and breast cancer cells. ZnCl(2) enhanced MI-219 activity (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), apoptosis and colony formation), and chelation of zinc not only blocked the activity of MI-219, but also suppressed reactivation of the p53 and its downstream effector molecules p21(WAF1) and Bax. N,N,N'N'-tetrakis(-)[2-pyridylmethyl]-ethylenediamine (TPEN), a specific zinc chelator, but not 1,2-bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (Bapta-AM), a calcium chelator, blocked MI-219-induced apoptosis. Nuclear localization is a prerequisite for proper functioning of p53 and our results confirm that TPEN, and not Bapta-AM, could abrogate p53 nuclear localization and it interfered with p53 transcriptional activation. Addition of zinc suppressed the known p53 feedback MDM2 activation, which could be restored by TPEN. Co-immunoprecipitation studies verified that MI-219-mediated MDM2-p53 disruption could be suppressed by TPEN and restored by zinc. As such, single-agent therapies that target MDM2 inhibition, without supplemental zinc, may not be optimal in certain patients owing to the less recognized mild zinc deficiency among the 'at-risk population' as in the elderly who are more prone to cancers. Therefore, use of supplemental zinc with MI-219 will benefit the overall efficacy of MIs and this potent combination warrants further investigation.


Assuntos
Cloretos/farmacologia , Inibidores Enzimáticos/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Compostos de Zinco/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Quelantes/farmacologia , Neoplasias do Colo/metabolismo , Sinergismo Farmacológico , Células HCT116 , Humanos , Transcrição Gênica , Transfecção , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
4.
Chemotherapy ; 56(4): 280-4, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20714144

RESUMO

Catalytic therapy is a cancer treatment modality based on the generation of reactive oxygen species (ROS) through administration of ascorbate/medicinal herbal extracts and copper. It is known that antioxidants such as ascorbate also exhibit prooxidant activity in the presence of transition metals such as copper. Based on our work and that in the literature, in this review we propose a mechanism for the cytotoxic action of ascorbate against cancer cells. It involves redox cycling of exogenous/endogenous copper ions and the consequent generation of ROS leading to oxidative DNA breakage. Using human peripheral lymphocytes and the Comet assay, we have shown that ascorbic acid is able to cause oxidative breakage in cellular DNA. Such DNA degradation is inhibited by neocuproine (a Cu(I) sequestering agent) and scavengers of ROS indicating that the cellular DNA breakage involves the generation of Cu(I) and formation of ROS. Similar results are also obtained with plant polyphenol antioxidants that are important constituents of medicinal herbal extracts. Copper is an essential component of chromatin and can take part in redox reactions. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and ascorbate/plant polyphenols to generate ROS. In this review we cite evidence to indicate that in catalytic therapy cytotoxic action against cancer cells involves redox cycling of exogenous/endogenous copper ions.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ácido Ascórbico/uso terapêutico , Cobre/metabolismo , Neoplasias/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Ácido Ascórbico/metabolismo , Quebras de DNA , Clivagem do DNA , Flavonoides/metabolismo , Flavonoides/farmacologia , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Neoplasias/metabolismo , Oxirredução
5.
Pharm Res ; 27(6): 979-88, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20119749

RESUMO

Plant polyphenols are important components of human diet, and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring anti-oxidants but also act as pro-oxidants catalyzing DNA degradation in the presence of metal ions such as copper. The plant polyphenol resveratrol confers resistance to plants against fungal agents and has been implicated as a cancer chemopreventive agent. Of particular interest is the observation that resveratrol has been found to induce apoptosis in cancer cell lines but not in normal cells. Over the last few years, we have shown that resveratrol is capable of causing DNA breakage in cells such as human lymphocytes. Such cellular DNA breakage is inhibited by copper specific chelators but not by iron and zinc chelating agents. Similar results are obtained by using permeabilized cells or with isolated nuclei, indicating that chromatin-bound copper is mobilized in this reaction. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and resveratrol to generate reactive oxygen species responsible for DNA cleavage. The results are in support of our hypothesis that anti-cancer mechanism of plant polyphenols involves mobilization of endogenous copper and the consequent pro-oxidant action. Such a mechanism better explains the anti-cancer effects of resveratrol, as it accounts for the preferential cytotoxicity towards cancer cells.


Assuntos
Anticarcinógenos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Cobre/metabolismo , Dano ao DNA/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Neoplasias/prevenção & controle , Estilbenos/farmacologia , Anticarcinógenos/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Quimioprevenção , Humanos , Linfócitos/metabolismo , Resveratrol , Estilbenos/uso terapêutico
6.
Toxicol Appl Pharmacol ; 218(3): 249-55, 2007 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-17208261

RESUMO

Plant-derived dietary material contains several classes of polyphenols such as flavonoids, curcuminoids, stilbenes and hydroxycinnamic acids. They are recognized as naturally occurring antioxidants but also act as prooxidants catalyzing cellular DNA degradation in the presence of transition metal ions such as copper. Earlier we have shown that the stilbene resveratrol is able to mobilize endogenous copper ions leading to oxidative breakage of cellular DNA. In this paper, we show that caffeic acid (a hydroxycinnamic acid), which is a major constituent of coffee, is also capable of DNA breakage in human peripheral lymphocytes. Incubation of lymphocytes with neocuproine inhibited the DNA degradation confirming that Cu(I) is an intermediate in the DNA cleavage reaction. Further, we have also shown that caffeic acid generates oxidative stress in lymphocytes, which is inhibited by scavengers of reactive oxygen species and neocuproine. These results are in further support of our hypothesis that anticancer mechanism of plant polyphenols involves mobilization of endogenous copper, possibly chromatin bound copper, and the consequent prooxidant action.


Assuntos
Antineoplásicos/metabolismo , Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Cobre/metabolismo , Dano ao DNA , DNA/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Quelantes/metabolismo , Quelantes/farmacologia , Ensaio Cometa , Cobre/química , Ácidos Cumáricos/farmacologia , Quebras de DNA , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Sequestradores de Radicais Livres/farmacologia , Ácido Gálico/metabolismo , Ácido Gálico/farmacologia , Humanos , Linfócitos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenantrolinas/metabolismo , Fenantrolinas/farmacologia , Propionatos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
7.
Med J Malaysia ; 62(3): 238-40, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18246915

RESUMO

This study was designed to identify surface and subsurface microscopic changes in different carious lesions by using Confocal Laser Scanning Microscope (CLSM) and Image analyzer (light microscopy). Thirty extracted carious posterior teeth were fixed, embedded and polymerized in plastic fixation medium. The final thin sections (80mm) were stained with H&E and Masson Goldner's Tricome while others were left unstained. Under Confocal, marked differences between control sound enamel and dentin, and carious area of the samples were observed which illustrated that a correlation existed between the zone of autofluoresence, demineralization and carious enamel and dentin. Compared to CLSM, Image Analyzer only produce two-dimensional images but the histopathological changes were better appreciated by using various staining methods.


Assuntos
Cárie Dentária , Esmalte Dentário , Processamento de Imagem Assistida por Computador , Microscopia Confocal , Humanos
8.
Toxicol In Vitro ; 18(4): 435-40, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15130600

RESUMO

Previous reports from this laboratory have shown that flavonoids including apigenin are capable of inducing oxidative DNA cleavage in the presence of copper ions. In the present report, we have examined the ability of amentoflavone, a biflavonoid which is a dimer of apigenin, to catalyze the degradation of DNA. Amentoflavone was found to degrade calf thymus DNA in the presence of Cu(II) at a rate almost twice that of apigenin. Amentoflavone was also shown to reduce Cu(II) to Cu(I) and to generate hydroxyl radicals in the presence of copper ions. In the presence of Cu(II), the absorption spectrum of amentoflavone undergoes a shift and a quenching effect indicating that the biflavonoid is capable of binding to copper ions. Amentoflavone and apigenin were isolated from Cycas rumphii and Trifolium alexandrinum, respectively. The results are discussed in relation to the putative chemopreventive mechanism of amentoflavone.


Assuntos
Biflavonoides/toxicidade , Cobre/farmacologia , Dano ao DNA , DNA/metabolismo , Animais , Anticarcinógenos/farmacologia , Bovinos , Quimioprevenção , Radical Hidroxila/química , Oxidantes/química , Oxirredução , Timo/química
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