RESUMO
BACKGROUND: Inappropriate matching of motor and sensory fibers after nerve repair or grafting can lead to nerve recovery failure. Identifying the motor and sensory fascicles enables surgeons to match them accurately and correctly align nerve stumps, which is crucial for neural regeneration. Very few methods have been reported to differentiate between the sensory and motor nerve fascicles, and the replicability of these techniques remains unestablished. In this study, we aimed to assess the accuracy of axonal cholinesterase (CE) histochemical staining in distinguishing motor and sensory nerve fibers. METHODS: The femoral and sciatic nerves were harvested from rats. The specimens were immediately cut, frozen in isopentane, and cooled with liquid nitrogen. Nerve serial cross-sections were processed for hematoxylin and eosin staining, followed by CE histochemistry. The staining protocol solutions included acetylthiocholine iodide, phosphate buffer, cobalt sulfate hydrate, potassium phosphate monobasic, sulfuric acid, sodium bicarbonate, glutaraldehyde, and ammonium sulfide. RESULTS: Cross-sections of nerves containing efferent and afferent nerve fibers in segregated fascicles showed that CE activity was confined to motor neurons. A histochemical study revealed that motor fibers with high cholinesterase activity can be differentiated from sensory fibers. The motor branches of the femoral and sciatic nerves showed specific axonal staining, whereas the sensory branch did not show any specific staining. CONCLUSION: CE histochemical staining is a useful technique for distinguishing between motor and sensory nerve fibers. It can be potentially useful in improving the outcomes of nerve grafts or extremity allotransplantation surgery.
Assuntos
Colinesterases , Neurônios Motores , Nervo Isquiático , Coloração e Rotulagem , Animais , Nervo Isquiático/enzimologia , Ratos , Colinesterases/metabolismo , Colinesterases/análise , Coloração e Rotulagem/métodos , Neurônios Motores/enzimologia , Axônios/enzimologia , Células Receptoras Sensoriais/enzimologia , Masculino , Nervo Femoral , Ratos Sprague-DawleyRESUMO
BACKGROUND: The lack of noninvasive biomarkers for graft rejection remains a challenge for the accurate monitoring of vascularized composite allotransplants. Viral vector-mediated gene transfer is a promising method for preventing graft rejection. In this study, we aimed to establish the expression profile of microRNAs (miRNAs) in skin flap allotransplantation, with or without gene transfer, and determine the potential role of several miRNAs as biomarkers of acute rejection and immune tolerance. METHODS: An abdominal epigastric flap was transplanted from SD (RT1a) to Wistar rats (RT1Au). The adenoviral interleukin 10 (vIL-10) gene was transferred to the experimental group via flap pedicle injection. Postoperatively, flap appearance, hematoxylin and eosin staining, immunohistochemical staining, and miRNA expression analyses were performed. RESULTS: The viral IL-10 gene-treated group showed improved flap survival and reduced acute rejection response compared with the control group. On postoperative day 7, IL-10 expression in the flap was identified using immunohistochemistry and real-time polymerase chain reaction. The expression of miR-191a, miR-31a, miR-16, and miR-3473 was upregulated in the skin tissue, and that of miR-484, miR-132, miR-139, miR-150, and miR-6216 was upregulated in the serum. CONCLUSION: AV IL-10 gene transfer could be an effective immunosuppressive strategy for the prevention of skin flap allograft rejection. Additionally, some miRNAs were upregulated in the experimental group, serving as potential biomarkers of immune tolerance.
Assuntos
Rejeição de Enxerto , Sobrevivência de Enxerto , Interleucina-10 , MicroRNAs , Ratos Wistar , Retalhos Cirúrgicos , Animais , MicroRNAs/genética , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/genética , Rejeição de Enxerto/prevenção & controle , Ratos , Interleucina-10/genética , Ratos Sprague-Dawley , Masculino , Transplante de Pele , Técnicas de Transferência de GenesRESUMO
Facial bone fractures are relatively common, with the nasal bone the most frequently fractured facial bone. Computed tomography is the gold standard for diagnosing such fractures. Most nasal bone fractures can be treated using a closed reduction. However, delayed diagnosis may cause nasal deformity or other complications that are difficult and expensive to treat. In this study, the authors developed an algorithm for diagnosing nasal fractures by learning computed tomography images of facial bones with artificial intelligence through deep learning. A significant concordance with human doctors' reading results of 100% sensitivity and 77% specificity was achieved. Herein, the authors report the results of a pilot study on the first stage of developing an algorithm for analyzing fractures in the facial bone.
Assuntos
Aprendizado Profundo , Fraturas Múltiplas , Fraturas Cranianas , Humanos , Inteligência Artificial , Projetos Piloto , Fraturas Cranianas/diagnóstico por imagem , Ossos Faciais , AlgoritmosRESUMO
BACKGROUND: Viral vector-mediated interleukin 10 gene transfer is one of the most promising methods for the prevention of graft rejection. Adeno-associated virus (AAV) is a nonpathogenic helper-dependent parvovirus. This is one of the most promising vehicles for gene delivery. Our study aimed to analyze the immune-suppressive potential of recombinant adeno-associated virus-mediated rat IL-10 in rat skin allograft. METHODS: Dorsal skin from Sprague-Dawley rats was grafted to Fischer 344 rats. In vivo AAV-viral IL-10 (vIL-10) gene transfer was done in the experimental group by direct subcutaneous injection. Observation of graft appearance, cytologic and immunohistochemical testing, and confocal immunofluorescence were performed at postoperative days 5 and 10. RESULTS: The viral IL-10 gene-treated group showed improved graft survival and reduced acute rejection response compared to the control group. IL-10 expression on skin was identified by immunohistochemistry and confocal microscopy. CONCLUSION: AAV IL-10 gene transfer could be an effective immunosuppressive method for preventing skin allograft rejection.
Assuntos
Rejeição de Enxerto , Sobrevivência de Enxerto , Interleucina-10 , Aloenxertos , Animais , Técnicas de Transferência de Genes , Vetores Genéticos , Rejeição de Enxerto/prevenção & controle , Interleucina-10/genética , Ratos , Ratos Sprague-Dawley , Transplante HomólogoRESUMO
RATIONALE: Pilomatricoma is a benign skin appendageal tumor derived from hair follicle matrix cells that commonly affects the head, neck, and upper extremities of the pediatric population. Since the original tumor description, diverse variants have been reported in the literature. Pilomatricoma with florid osseous metaplasia is described as an ossifying pilomatricoma and is recognized as a distinct variant of this benign tumor. However, the pathogenesis of this variant remains unclear. In this study, we present an uncommon case of ossifying pilomatricoma and address the pathogenesis of metaplastic ossification through a comprehensive literature review. PATIENT CONCERNS: A 14-year-old boy presented with an asymptomatic protuberant mass in the preauricular region. DIAGNOSIS: Based on its clinicopathological features, we diagnosed the lesion as an ossifying pilomatricoma. INTERVENTIONS AND OUTCOMES: The lesion was surgically removed under local anesthesia. The postoperative course was uneventful during the 6-month postoperative follow-up. LESSONS: We suggest that metaplastic ossification in ossifying pilomatricoma represents another feature of foreign body reaction to keratinous materials containing shadow cells in old lesions and a walling-off phenomenon to prevent exposure of surrounding tissues to keratinous materials.
Assuntos
Calcinose , Metaplasia/patologia , Pilomatrixoma/patologia , Adolescente , Coristoma , Reação a Corpo Estranho , Doenças do Cabelo/etiologia , Doenças do Cabelo/cirurgia , Humanos , Masculino , Osteogênese , Pilomatrixoma/cirurgia , Neoplasias Cutâneas/cirurgiaRESUMO
BACKGROUND: Peripheral nerve regeneration is essential for functional recovery after traumatic limb injury or limb transplantation. With the use of immunosuppression, it has the capacity to provide regeneration and function equal to that of an autograft. The purpose of this study was to determine whether there is any difference in regeneration and rejection response between peripheral femoral and sciatic nerve in rat hindlimb allotransplantation model. METHODS: The hindlimbs of recipient Fischer 344 rats were amputated at the mid-thigh and the donor and recipient femurs were joined by an intramedullary rod. The femoral and sciatic nerves were repaired with 10-O nylon end-to-end suture followed by vessel, muscle, and skin closure. The control group received auto-transplantation and the experimental group received allo-transplantation from Sprague-Dawley donor rats. The recipients were treated with an immunosuppressive agent, FK506 (2 mg/kg), for the observation period. Both sciatic and femoral nerves were harvested 10 weeks after operation and histomorphometric analysis was conducted between these 2 nerves and control group. RESULTS: The sciatic nerve showed better regeneration, with significantly increased percentage nerve, fiber count, and density (P < .05), but demonstrated more immune cell proliferation relative to femoral nerve. CONCLUSIONS: The data showed that there are some differences in axonal regeneration capacity and immune response between large peripheral nerves.
Assuntos
Regeneração Nervosa , Nervo Isquiático , Animais , Fêmur/cirurgia , Membro Posterior/transplante , Humanos , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/fisiologia , Nervo Isquiático/cirurgiaRESUMO
Intravascular papillary endothelial hyperplasia is an uncommon benign vascular lesion characterized by a reactive proliferation of endothelial cells. The lesion of the finger often presents diagnostic challenges to surgeons because of its rarity. We report a case of intravascular papillary endothelial hyperplasia to facilitate the recognition of this uncommon lesion.
RESUMO
A classic pilomatricoma, which usually presents with an asymptomatic, solitary, firm, subcutaneous nodule in the head, neck, or extremities of the paediatric population, is easily diagnosed based on its characteristic clinical and histopathological features. However, its variants often pose particular diagnostic challenges to clinicians due to their rarity and diverse clinicopathological features. We present a new pseudocystic variant, manifesting as solid lesions floating in a fluid-filled sac.
Assuntos
Doenças do Cabelo/patologia , Pilomatrixoma/patologia , Neoplasias Cutâneas/patologia , Pré-Escolar , Extremidades/patologia , Extremidades/cirurgia , Feminino , Doenças do Cabelo/diagnóstico por imagem , Doenças do Cabelo/cirurgia , Humanos , Pilomatrixoma/diagnóstico por imagem , Pilomatrixoma/cirurgia , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/cirurgia , UltrassonografiaRESUMO
Cytoplasmic accumulation of TDP-43 in motor neurons is the most prominent pathological feature in amyotrophic lateral sclerosis (ALS). A feedback cycle between nucleocytoplasmic transport (NCT) defect and TDP-43 aggregation was shown to contribute to accumulation of TDP-43 in the cytoplasm. However, little is known about cellular factors that can control the activity of NCT, thereby affecting TDP-43 accumulation in the cytoplasm. Here, we identified via FRAP and optogenetics cytosolic calcium as a key cellular factor controlling NCT of TDP-43. Dynamic and reversible changes in TDP-43 localization were observed in Drosophila sensory neurons during development. Genetic and immunohistochemical analyses identified the cytosolic calcium-Calpain-A-Importin α3 pathway as a regulatory mechanism underlying NCT of TDP-43. In C9orf72 ALS fly models, upregulation of the pathway activity by increasing cytosolic calcium reduced cytoplasmic accumulation of TDP-43 and mitigated behavioral defects. Together, these results suggest the calcium-Calpain-A-Importin α3 pathway as a potential therapeutic target of ALS.
Assuntos
Cálcio/metabolismo , Calpaína/metabolismo , Citoplasma/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , alfa Carioferinas/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Esclerose Lateral Amiotrófica/metabolismo , Animais , Drosophila melanogaster , Neurônios/metabolismoRESUMO
Mixed tumor of the skin (MTS) is a rare skin adnexal neoplasm occurring in sweat glands. It is usually benign, measures 0.5 to 3 cm, and presents as a slowly growing, painless, firm nodule commonly in the head and neck regions. Owing to its rarity and lack of distinctive clinical manifestations, confirmative diagnosis is made on the basis of its pathologic features. Malignant MTS also develops de novo or from preexisting benign MTS even though they occur rarely. It should be excised completely to exclude malignant potentials. Herein, we report a 35-year history of a giant MTS of eccrine type measuring approximately 10.5 × 6.5 cm on the right hemiface of a 91-year-old woman, which is the largest facial MTS reported in the literature so far, to the best of our knowledge.
Assuntos
Neoplasias Faciais/cirurgia , Neoplasias Complexas Mistas/cirurgia , Neoplasias Cutâneas/cirurgia , Neoplasias das Glândulas Sudoríparas/cirurgia , Idoso de 80 Anos ou mais , Neoplasias Faciais/patologia , Feminino , Humanos , Neoplasias Cutâneas/patologia , Neoplasias das Glândulas Sudoríparas/patologiaRESUMO
BACKGROUND: The development of consistent animal experimental models is important for continued research on specific biological and immunologic aspects of vascularized composite allografts. It is also important for the translation of immune regulation and tolerance induction strategies and treatment ideas from bench to bedside. The purpose of our study is to provide an outline of the use of animal models in simulated facial transplant surgery and to investigate the feasibility of animal model use. METHODS: The animals underwent hemifacial flap transplant surgery. The flaps were placed on the external carotid artery and external jugular vein of the donor animal. Twenty-one procedures were performed in 4 different animals (6 rats, 5 rabbits, 6 dogs, 4 pigs). Two experienced plastic surgeons and 5 students performed allotransplant. RESULTS: All 4 models were suitable for facial allotransplant with different anatomic characteristics. Average feasibility scores were 4.8 for pigs, 3.6 for rabbits, 3.2 for dogs, and 3.4 for rats. Evaluations concluded that pigs were the most practical and realistic models for facial allotransplant training. Other models achieved validation thresholds. CONCLUSIONS: This study is the first comparative validation assessment of animal models used in facial allotransplant. It supports the use of pig models for surgical skills training. Pigs were the preferred simulation models, while rats, rabbits, and dogs were considered inferior models for transplant simulation.
Assuntos
Modelos Animais de Doenças , Transplante de Face/métodos , Animais , Cães , Coelhos , Ratos , SuínosRESUMO
BACKGROUND: Expression of genes with immunoregulatory capacity can potentially decrease rejection of allograft. According to recent studies, viral interleukin (IL)-10 can reduce immune response during allotransplantation and is one of the most promising methods for the prevention of rejection. Our study aimed to analyze the immunosuppressive potential of recombinant adenovirus-mediated rat IL-10 in rat skin allograft. METHODS: We performed skin graft surgery 1 hour after infecting the donated skin with adenovirus-mediated rat IL-10. On day 7 postoperatively, the skin allografts were harvested, and acute rejection was graded histologically. RESULTS: Viral IL-10 gene transfer into rat skin allografts improved graft survival and reduced acute rejections. CONCLUSION: The results of our study suggest that the therapeutic potential of graft viral IL-10 gene transfer is an effective immunosuppressive method for preventing skin allograft rejection.
Assuntos
Terapia Genética/métodos , Rejeição de Enxerto/imunologia , Interleucina-10/imunologia , Transplante de Pele , Adenoviridae/genética , Animais , Vetores Genéticos , Rejeição de Enxerto/prevenção & controle , Interleucina-10/genética , Masculino , Ratos , Ratos Endogâmicos F344 , Ratos Endogâmicos Lew , Transfecção/métodos , Transplante HomólogoRESUMO
PURPOSE: We aimed to classify nonpharmacological interventions used for preventing delirium in the intensive care unit (ICU), and estimate their effect size. MATERIALS AND METHODS: In this systematic review and meta-analysis, the literature was searched and studies were selected based on the PRISMA flow chart. Data sources included MEDLINE, Cochrane, CINHAHL, PsyInfo, and EMBASE. We used Cochrane's Effective Practice and Organisation of Care (EPOC) criteria in study design and quality assessment of the meta-analysis. RESULTS: This systematic review and meta-analysis included 35 and 15 studies, respectively. Studies were grouped into nine intervention types: multicomponent (16 studies), physical environment (9), daily interruption of sedation (2), exercise (2), patient education (2), automatic warning system (1), cerebral hemodynamics improving (1), family participation (1), and sedation reducing protocol (1). The effect size of preventive nonpharmacological interventions had an odds ratio (OR) of 0.66 (95% confidence interval [CI], 0.50-0.86) for delirium occurrence, and an OR of 0.31 (95% CI, 0.10-0.94) for delirium duration. Although relevant studies by interventions were lacking, a partial subgroup analysis by intervention was performed. CONCLUSIONS: Nonpharmacological interventions were effective in reducing the duration and occurrence of delirium. Consistent application and development of nonpharmacological interventions for use in the ICU are important.
Assuntos
Delírio/prevenção & controle , Delírio/terapia , Unidades de Terapia Intensiva/estatística & dados numéricos , Delírio/mortalidade , Humanos , Tempo de Internação/estatística & dados numéricos , Razão de Chances , Projetos de PesquisaRESUMO
(-)-Epigallocatechin-3-gallate (EGCG), a major green tea polyphenol, was tested for in vitro cytotoxicity against human laryngeal epidermoid carcinoma of the larynx Hep2 cells. EGCG-induced apoptotic cell death accompanied by a change in the cell cycle. However, EGCG did not result in caspase activation, nor did a caspase inhibitor block cell death. Furthermore, EGCG caused no change in the intracellular levels of reactive oxygen species (ROS). The levels of p53 were increased in the EGCG-treated cells, with a corresponding decrease in Bcl-2 and Bid protein levels as well as an increase in the Bax level. In addition, EGCG induced the cytoplasmic release of cytochrome c from the mitochondria accompanied by a decreased mitochondrial membrane potential, and subsequently upregulated translocation of apoptosis-inducing factor (AIF) and endonuclease G (EndoG) into the nucleus during the apoptotic process. Taken together, these findings indicate that the p53-mediated mitochondrial pathway and the nuclear translocation of AIF and EndoG play a crucial role in EGCG-induced apoptosis of human laryngeal epidermoid carcinoma Hep2 cells, which proceeds through a caspase-independent pathway.
Assuntos
Anticarcinógenos/farmacologia , Fator de Indução de Apoptose/metabolismo , Carcinoma de Células Escamosas/metabolismo , Catequina/análogos & derivados , Endodesoxirribonucleases/metabolismo , Neoplasias Laríngeas/metabolismo , Fator de Indução de Apoptose/efeitos dos fármacos , Western Blotting , Catequina/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Endodesoxirribonucleases/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismoRESUMO
Cyclosporin A (CsA), an immunosuppressive drug, has overgrowth effects on human gingival fibroblasts (HGF) in vitro. However, the molecular mechanism responsible for the CsA-induced gingival overgrowth remains still unclear. The present study is aimed to investigate the correlation with the apoptotic signal pathway in CsA-induced overgrowth of HGF. CsA-treated HGF were assessed for cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, for reactive oxygen species (ROS) detection by flow cytometry, for proliferation ability using the 5-bromo-20-deoxyuridine (BrdU), for caspase activities biochemically, for expression of apoptotic signal molecules such as cytochrome c, Fas and Fas-L and Bcl-2 family by Western blotting and VDAC by RT-PCR. CsA increased the cell viability, but not the number of BrdU-positive HGF, indicating that CsA fails to induce the proliferation of HGF. CsA also decreased the intracellular reactive oxygen species level in HGF. This was accompanied by that the antiapoptotic protein Bcl-2 was upregulated whereas the proapoptotic protein Bax was downregulated. Moreover, CsA downregulated VDAC, a mitochondrial transition pore, and decreased the level of cytochrome c released from the mitochondria into the cytosol and activation of caspase-3 and -9 associated with mitochondria-mediated apoptosis. On the other hand, Fas-L level and caspase-8 activation, the major mediator of the death receptor-mediated apoptosis, were diminished in the CsA-treated HGF. CsA inhibits the apoptotic signal molecules such as cytochrome c, caspases and Fas-L with the regulation of Bcl-2 family whereas it has no effect on cell division, which can contribute to overgrowth of HGF. These findings suggest that the decreased apoptosis plays a more important role than the increased cell proliferation in the CsA-induced overgrowth of HGF.
Assuntos
Apoptose/efeitos dos fármacos , Ciclosporina/farmacologia , Fibroblastos/efeitos dos fármacos , Gengiva/efeitos dos fármacos , Imunossupressores/farmacologia , Apoptose/fisiologia , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ciclosporina/administração & dosagem , Citocromos c/metabolismo , Citosol/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Proteína Ligante Fas/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Gengiva/citologia , Gengiva/metabolismo , Humanos , Imunossupressores/administração & dosagem , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismoRESUMO
Sodium fluoride (NaF) has been shown to be cytotoxic and produces inflammatory responses in humans. However, the cellular mechanisms underlying the NaF-induced cytotoxicity in periodontal tissues are unclear. This study examined whether or not NaF induces apoptosis in human gingival fibroblasts (HGF), and its underlying mechanisms by monitoring various apoptosis-associated processes. NaF reduced the cell viability of HGF in a dose- and time-dependent manner. NaF increased TUNEL-positive cell and induced apoptosis with concomitant chromatin condensation and DNA fragmentation in HGF. In addition, NaF increased the level of cytochrome c released from the mitochondria into the cytosol, enhanced the caspase-9, -8 and -3 activities, the cleavage of poly (ADP-ribose) polymerase (PARP), and up-regulated the voltage-dependent anion channel (VDAC) 1. However, NaF did not affect the production of reactive oxygen species (ROS) which is a strong apoptotic inducer. Furthermore, NaF up-regulated the Fas-ligand (Fas-L), a ligand of death receptor. Bcl-2, a member of the anti-apoptotic Bcl-2 family, was down-regulated, whereas the expression of Bax, a member of the pro-apoptotic Bcl-2 family, was unaffected in the NaF-treated HGF. These results suggest that NaF induces apoptosis in HGF through both the mitochondria-mediated pathways regulated by the Bcl-2 family and death receptor-mediated pathway.
Assuntos
Apoptose/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Morte Celular/metabolismo , Fluoreto de Sódio/farmacologia , Western Blotting , Caspases/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cromatina/efeitos dos fármacos , Cromatina/metabolismo , Citocromos c/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Proteína Ligante Fas/genética , Proteína Ligante Fas/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Gengiva/citologia , Humanos , Mitocôndrias/metabolismo , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Proteína X Associada a bcl-2/metabolismo , Proteína de Morte Celular Associada a bcl/metabolismoRESUMO
Epigallocatechin-3-gallate (EGCG) is a major constituent of green tea polyphenols. This study was aimed to investigate the possible mechanisms of EGCG-mediated inhibition against apoptosis in rat pheochromocytoma PC12 cells by exposure to CoCl(2). Exposure to CoCl(2) caused the generation of ROS and induced cell death with appearance of apoptotic morphology and DNA fragmentation. However, EGCG rescued the loss of viability in the cells exposed to CoCl(2) and led the reduction of DNA fragmentation and sub-G(1) fraction of cell cycle. Also, EGCG attenuated the CoCl(2)-induced disruption of mitochondrial membrane potential (DeltaPsim), release of cytochrome c from the mitochondria to cytosol and abolished the CoCl(2)-stimulated activities of the caspase cascades, caspase-9 and caspase-3. In addition, EGCG ameliorated the increase in the Bax to Bcl-2 ratio, a marker of apoptosis proceeding, induced by CoCl(2) treatment. Taken together, the present results suggest that EGCG inhibit the CoCl(2)-induced apoptosis of PC12 cells through the mitochondria-mediated apoptosis pathway involved in modulating the Bcl-2 family.