Daniel Diaz - Academia.edu (original) (raw)
Papers by Daniel Diaz
Acta Medica (Hradec Kralove, Czech Republic), 2015
The cell culture became an invaluable tool for studying cell behaviour, development, function, ge... more The cell culture became an invaluable tool for studying cell behaviour, development, function, gene expression, toxicity of compounds and efficacy of novel drugs. Although most results were obtained from cell cultivation in two-dimensional (2D) systems, in which cells are grown in a monolayer, three-dimensional (3D) cultures are more promising as they correspond closely to the native arrangement of cells in living tissues. In our study, we focused on three types of 3D in vitro systems used for cultivation of one cell type. Cell morphology, their spatial distribution inside of resulting multicellular structures and changes in time were analysed with histological examination of samples harvested at different time periods. In multilayered cultures of WRL 68 hepatocytes grown on semipermeable membranes and non-passaged neurospheres generated by proliferation of neural progenitor cells, the cells were tightly apposed, showed features of cell differentiation but also cell death that was o...
Summary: High grade gliomas are some of the deadliest human tumours. Conventional treatments such... more Summary: High grade gliomas are some of the deadliest human tumours. Conventional treatments such as surgery, radio-therapy and chemotherapy have only a limited effect. Nowadays, resection is the common treatment of choice and although new approaches, such as perioperative magnetic resonance imaging or fluorescent microscopy have been developed, the survival rate of diagnosed patients is still very low. The inefficacy of conventional methods has led to the development of new strategies and the significant progress of nanotechnology in recent years. These platforms can be used either as novel imaging tools or to improve anticancer drug delivery into tumours while minimizing its distribution and toxicity in healthy tissues. Amongst the new nanotechnology platforms used for delivery into the brain tissue are: polymeric nanoparticles, liposomes, dendrimers, nanoshells, carbon nanotubes, superparamagnetic nanoparticles and nucleic acid based nanopar-ticles (DNA, RNA interference [RNAi] a...
Summary: Ovarian cancer is the fifth most common malignancy in the world’s female population and ... more Summary: Ovarian cancer is the fifth most common malignancy in the world’s female population and with the highest lethality index among gynecological tumors. The prognosis of metastatic disease is usually poor, especially in platinum-re-sistant cases. There are several options for the treatment of metastatic disease resistant to platinum derivates (e.g. paclitaxel, topotecan and pegylated liposomal doxorubicin), all of which are considered equipotent. Pegylated liposomal doxorubicin (PLD) is a liposomal form of the anthracycline antibiotic doxorubicin. It is characterized by more convenient pharmacoki-netics and a different toxicity profile. Cardiotoxicity, the major adverse effect of conventional doxorubicin, is reduced in PLD as well as hematotoxicity, alopecia, nausea and vomiting. Skin toxicity and mucositis, however, emerge as serious issues since they represent dose and schedule-limiting toxicities. The pharmacokinetics of PLD (prolonged biological half-life and preferential d...
Acta Medica (Hradec Kralove, Czech Republic), 2015
Ovarian cancer is the fifth most common malignancy in the world’s female population and with the ... more Ovarian cancer is the fifth most common malignancy in the world’s female population and with the highest lethality index among gynecological tumors. The prognosis of metastatic disease is usually poor, especially in platinum-resistant cases. There are several options for the treatment of metastatic disease resistant to platinum derivates (e.g. paclitaxel, topotecan and pegylated liposomal doxorubicin), all of which are considered equipotent. Pegylated liposomal doxorubicin (PLD) is a liposomal form of the anthracycline antibiotic doxorubicin. It is characterized by more convenient pharmacokinetics and a different toxicity profile. Cardiotoxicity, the major adverse effect of conventional doxorubicin, is reduced in PLD as well as hematotoxicity, alopecia, nausea and vomiting. Skin toxicity and mucositis, however, emerge as serious issues since they represent dose and schedule-limiting toxicities. The pharmacokinetics of PLD (prolonged biological half-life and preferential distribution...
Acta Medica (Hradec Kralove, Czech Republic), 2015
High grade gliomas are some of the deadliest human tumours. Conventional treatments such as surge... more High grade gliomas are some of the deadliest human tumours. Conventional treatments such as surgery, radiotherapy and chemotherapy have only a limited effect. Nowadays, resection is the common treatment of choice and although new approaches, such as perioperative magnetic resonance imaging or fluorescent microscopy have been developed, the survival rate of diagnosed patients is still very low. The inefficacy of conventional methods has led to the development of new strategies and the significant progress of nanotechnology in recent years. These platforms can be used either as novel imaging tools or to improve anticancer drug delivery into tumours while minimizing its distribution and toxicity in healthy tissues. Amongst the new nanotechnology platforms used for delivery into the brain tissue are: polymeric nanoparticles, liposomes, dendrimers, nanoshells, carbon nanotubes, superparamagnetic nanoparticles and nucleic acid based nanoparticles (DNA, RNA interference [RNAi] and antisens...
Acta medica (Hradec Králové) / Universitas Carolina, Facultas Medica Hradec Králové, 2015
Though mid-term survival rates of over 95% in several series have been published, there is still ... more Though mid-term survival rates of over 95% in several series have been published, there is still a paucity of related literature regarding the role of vertical stem instability in the osteointegration of fluted tapered stems. This paper presents a comprehensive and prospective assessment on short-term experiences with uncemented modular femoral stem in the treatment of defective femur during revision surgery of total hip replacement. Clinical and radiological monitoring of 20 consecutive patients with implanted tapered fluted revision stem (Lima Corporate, Udine, Italy) was of 27 months in average (20-35 months). The average pre-operative Merle d'Aubigné and Postel method score was 6.3 points (3-10 points). The frequency of femur defects, classified according to Paprosky, was IIIA = 9 and IIIB = 11. During last follow-up, the Merle d'Aubigné and Postel hip score was on average 11.7 (6-16 points). Compared to post-operation radiograph, stem migration of 1.9 mm (0-11 mm) on av...
Tumori
Breast cancer is the most common type of malignant disease in women worldwide. In developing coun... more Breast cancer is the most common type of malignant disease in women worldwide. In developing countries the past few years have sustained an increasing incidence of this type of cancer. Currently, breast cancer is the second leading cause of death due to cancer in women. In 2008 alone it was diagnosed in more than 1 million patients and each year the number of breast cancer-related deaths is estimated to be ~450,000. The mortality rate in breast cancer patients has been decreasing over the years thanks to the development of early diagnostic methods and more effective treatments. But despite the new advances in cancer diagnosis and treatment, the risk of recurrence and metastasis is ever present. It has been theorized that cancer stem cells are involved in the process of tumor growth and metastases. Due to their self-renewing and differentiation capabilities, they are now considered the underlying factor in tumor recurrence and the main reason for therapy resistance. Therefore, the ch...
Journal of Bacteriology, 2011
Ace, a known virulence factor and the first identified microbial surface component recognizing ad... more Ace, a known virulence factor and the first identified microbial surface component recognizing adhesive matrix molecule (MSCRAMM) of Enterococcus faecalis is associated with host cell adherence and endocarditis. The Fsr quorum-sensing system of E. faecalis , a two-component signal transduction system, has also been repeatedly linked to virulence in E. faecalis , due in part to the transcriptional induction of an extracellular metalloprotease, gelatinase (GelE). In this study, we discovered that disruption of the Fsr pathway significantly increased the levels of Ace on the cell surface in the latter phases of growth. Furthermore, we observed that, in addition to fsrB mutants, other strains identified as deficient in GelE activity also demonstrated a similar phenotype. Additional experiments demonstrated the GelE-dependent cleavage of Ace from the surface of E. faecalis , confirming that GelE specifically reduces Ace cell surface display. In addition, disruption of the Fsr system or G...
International Journal of Molecular Sciences, 2021
The primary function of the skin is that of a physical barrier against the environment and divers... more The primary function of the skin is that of a physical barrier against the environment and diverse pathogens; therefore, its integrity is essential for survival. Skin regeneration depends on multiple stem cell compartments within the epidermis, which, despite their different transcriptional and proliferative capacity, as well as different anatomical location, fall under the general term of skin stem cells (SSCs). Skin wounds can normally heal without problem; however, some diseases or extensive damage may delay or prevent healing. Non-healing wounds represent a serious and life-threatening scenario that may require advanced therapeutic strategies. In this regard, increased focus has been directed at SSCs and their role in wound healing, although emerging therapeutical approaches are considering the use of other stem cells instead, such as mesenchymal stem cells (MSCs). Given its extensive and broad nature, this review supplies newcomers with an introduction to SSCs, wound healing, a...
Journal of Cellular and Molecular Medicine
This is an open access article under the terms of the Creat ive Commo ns Attri bution License, wh... more This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
International journal of oncology, 2012
The carcinogenic potential of HPV infections is based on the integration and constitutive express... more The carcinogenic potential of HPV infections is based on the integration and constitutive expression of the E6 and E7 genes which inhibit the p53 and Rb tumor suppressor proteins. In normal cells, Mdm2 regulates p53 in a negative feedback loop, and although Mdm2 is apparently functional in HPV-infected cells, E6 is the protein responsible for repressing p53 replacing Mdm2 function. The role of Mdm2 in HPV-positive cells is still elusive. In this study, Mdm2 was knocked down in an HPV-positive cervical cancer cell line; as a result we found downregulation of the expression of E6 and E7 and p53 upregulation.
Experimental and Therapeutic Medicine, May 1, 2012
Vitiligo is a skin disease characterized by depigmentation. Its etiopathogenesis is unclear, but ... more Vitiligo is a skin disease characterized by depigmentation. Its etiopathogenesis is unclear, but it has been associated with autoimmune processes. Gene polymorphisms in the tumor necrosis factor-α (TNF-α) have been associated with several imflammatory diseases. In particular, the-308G/A polymorphism in the gene promoter region has been reported to be associated with increased plasma levels of TNF-α and with an increased risk to develop autoimmune diseases. To date, this polymorphism has not been associated with vitiligo. ...
Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia, Jan 18, 2013
A biological scaffold from extracellular matrix can be produced by a variety of decellularization... more A biological scaffold from extracellular matrix can be produced by a variety of decellularization methods whose caveat consists in efficiently eliminating cells from the treated tissue. This scaffold can be used in diverse applications for tissue engineering and organ regeneration. Preservation of the extracellular matrix ultrastructure is highly desirable because of its unique architecture, contained growth factors and decreased immunological response. All of these properties provide attachment sites and adequate environment for cells colonizing this scaffold, reconstituting the decellularized organ. This review briefly describes chemical decellularization methods, evaluation of these protocols and the role of ECM in tissue engineering. Chemical decellularization is an often used method for scaffold preparation and makes possible a well-preserved three dimensional structure of extracellular matrix.
International Journal of Molecular Sciences, 2014
Hair follicle morphogenesis depends on Wnt, Shh, Notch, BMP and other signaling pathways interpla... more Hair follicle morphogenesis depends on Wnt, Shh, Notch, BMP and other signaling pathways interplay between epithelial and mesenchymal cells. The Wnt pathway plays an essential role during hair follicle induction, Shh is involved in morphogenesis and late stage differentiation, Notch signaling determines stem cell fate while BMP is involved in cellular differentiation. The Wnt pathway is considered to be the master regulator during hair follicle morphogenesis. Wnt signaling proceeds through EDA/EDAR/NF-κB signaling. NF-κB regulates the Wnt pathway and acts as a signal mediator by upregulating the expression of Shh ligand. Signal crosstalk between epithelial and mesenchymal cells takes place mainly through primary cilia. Primary cilia formation is initiated with epithelial laminin-511 interaction with dermal β-1 integrin, which also upregulates expression of downstream effectors of Shh pathway in dermal lineage. PDGF signal transduction essential for crosstalk is mediated through epithelial PDGF-A and PDGFRα expressed on the primary cilia. Dermal Shh and PDGF signaling up-regulates dermal noggin expression; noggin is a potent inhibitor of BMP signaling which helps in counteracting BMP mediated β-catenin inhibition. This interplay of signaling between the epithelial and dermal lineage helps in epithelial Shh signal amplification. The dermal Wnt pathway helps in upregulation OPEN ACCESS
Acta Medica (Hradec Kralove, Czech Republic), 2015
The cell culture became an invaluable tool for studying cell behaviour, development, function, ge... more The cell culture became an invaluable tool for studying cell behaviour, development, function, gene expression, toxicity of compounds and efficacy of novel drugs. Although most results were obtained from cell cultivation in two-dimensional (2D) systems, in which cells are grown in a monolayer, three-dimensional (3D) cultures are more promising as they correspond closely to the native arrangement of cells in living tissues. In our study, we focused on three types of 3D in vitro systems used for cultivation of one cell type. Cell morphology, their spatial distribution inside of resulting multicellular structures and changes in time were analysed with histological examination of samples harvested at different time periods. In multilayered cultures of WRL 68 hepatocytes grown on semipermeable membranes and non-passaged neurospheres generated by proliferation of neural progenitor cells, the cells were tightly apposed, showed features of cell differentiation but also cell death that was o...
Summary: High grade gliomas are some of the deadliest human tumours. Conventional treatments such... more Summary: High grade gliomas are some of the deadliest human tumours. Conventional treatments such as surgery, radio-therapy and chemotherapy have only a limited effect. Nowadays, resection is the common treatment of choice and although new approaches, such as perioperative magnetic resonance imaging or fluorescent microscopy have been developed, the survival rate of diagnosed patients is still very low. The inefficacy of conventional methods has led to the development of new strategies and the significant progress of nanotechnology in recent years. These platforms can be used either as novel imaging tools or to improve anticancer drug delivery into tumours while minimizing its distribution and toxicity in healthy tissues. Amongst the new nanotechnology platforms used for delivery into the brain tissue are: polymeric nanoparticles, liposomes, dendrimers, nanoshells, carbon nanotubes, superparamagnetic nanoparticles and nucleic acid based nanopar-ticles (DNA, RNA interference [RNAi] a...
Summary: Ovarian cancer is the fifth most common malignancy in the world’s female population and ... more Summary: Ovarian cancer is the fifth most common malignancy in the world’s female population and with the highest lethality index among gynecological tumors. The prognosis of metastatic disease is usually poor, especially in platinum-re-sistant cases. There are several options for the treatment of metastatic disease resistant to platinum derivates (e.g. paclitaxel, topotecan and pegylated liposomal doxorubicin), all of which are considered equipotent. Pegylated liposomal doxorubicin (PLD) is a liposomal form of the anthracycline antibiotic doxorubicin. It is characterized by more convenient pharmacoki-netics and a different toxicity profile. Cardiotoxicity, the major adverse effect of conventional doxorubicin, is reduced in PLD as well as hematotoxicity, alopecia, nausea and vomiting. Skin toxicity and mucositis, however, emerge as serious issues since they represent dose and schedule-limiting toxicities. The pharmacokinetics of PLD (prolonged biological half-life and preferential d...
Acta Medica (Hradec Kralove, Czech Republic), 2015
Ovarian cancer is the fifth most common malignancy in the world’s female population and with the ... more Ovarian cancer is the fifth most common malignancy in the world’s female population and with the highest lethality index among gynecological tumors. The prognosis of metastatic disease is usually poor, especially in platinum-resistant cases. There are several options for the treatment of metastatic disease resistant to platinum derivates (e.g. paclitaxel, topotecan and pegylated liposomal doxorubicin), all of which are considered equipotent. Pegylated liposomal doxorubicin (PLD) is a liposomal form of the anthracycline antibiotic doxorubicin. It is characterized by more convenient pharmacokinetics and a different toxicity profile. Cardiotoxicity, the major adverse effect of conventional doxorubicin, is reduced in PLD as well as hematotoxicity, alopecia, nausea and vomiting. Skin toxicity and mucositis, however, emerge as serious issues since they represent dose and schedule-limiting toxicities. The pharmacokinetics of PLD (prolonged biological half-life and preferential distribution...
Acta Medica (Hradec Kralove, Czech Republic), 2015
High grade gliomas are some of the deadliest human tumours. Conventional treatments such as surge... more High grade gliomas are some of the deadliest human tumours. Conventional treatments such as surgery, radiotherapy and chemotherapy have only a limited effect. Nowadays, resection is the common treatment of choice and although new approaches, such as perioperative magnetic resonance imaging or fluorescent microscopy have been developed, the survival rate of diagnosed patients is still very low. The inefficacy of conventional methods has led to the development of new strategies and the significant progress of nanotechnology in recent years. These platforms can be used either as novel imaging tools or to improve anticancer drug delivery into tumours while minimizing its distribution and toxicity in healthy tissues. Amongst the new nanotechnology platforms used for delivery into the brain tissue are: polymeric nanoparticles, liposomes, dendrimers, nanoshells, carbon nanotubes, superparamagnetic nanoparticles and nucleic acid based nanoparticles (DNA, RNA interference [RNAi] and antisens...
Acta medica (Hradec Králové) / Universitas Carolina, Facultas Medica Hradec Králové, 2015
Though mid-term survival rates of over 95% in several series have been published, there is still ... more Though mid-term survival rates of over 95% in several series have been published, there is still a paucity of related literature regarding the role of vertical stem instability in the osteointegration of fluted tapered stems. This paper presents a comprehensive and prospective assessment on short-term experiences with uncemented modular femoral stem in the treatment of defective femur during revision surgery of total hip replacement. Clinical and radiological monitoring of 20 consecutive patients with implanted tapered fluted revision stem (Lima Corporate, Udine, Italy) was of 27 months in average (20-35 months). The average pre-operative Merle d'Aubigné and Postel method score was 6.3 points (3-10 points). The frequency of femur defects, classified according to Paprosky, was IIIA = 9 and IIIB = 11. During last follow-up, the Merle d'Aubigné and Postel hip score was on average 11.7 (6-16 points). Compared to post-operation radiograph, stem migration of 1.9 mm (0-11 mm) on av...
Tumori
Breast cancer is the most common type of malignant disease in women worldwide. In developing coun... more Breast cancer is the most common type of malignant disease in women worldwide. In developing countries the past few years have sustained an increasing incidence of this type of cancer. Currently, breast cancer is the second leading cause of death due to cancer in women. In 2008 alone it was diagnosed in more than 1 million patients and each year the number of breast cancer-related deaths is estimated to be ~450,000. The mortality rate in breast cancer patients has been decreasing over the years thanks to the development of early diagnostic methods and more effective treatments. But despite the new advances in cancer diagnosis and treatment, the risk of recurrence and metastasis is ever present. It has been theorized that cancer stem cells are involved in the process of tumor growth and metastases. Due to their self-renewing and differentiation capabilities, they are now considered the underlying factor in tumor recurrence and the main reason for therapy resistance. Therefore, the ch...
Journal of Bacteriology, 2011
Ace, a known virulence factor and the first identified microbial surface component recognizing ad... more Ace, a known virulence factor and the first identified microbial surface component recognizing adhesive matrix molecule (MSCRAMM) of Enterococcus faecalis is associated with host cell adherence and endocarditis. The Fsr quorum-sensing system of E. faecalis , a two-component signal transduction system, has also been repeatedly linked to virulence in E. faecalis , due in part to the transcriptional induction of an extracellular metalloprotease, gelatinase (GelE). In this study, we discovered that disruption of the Fsr pathway significantly increased the levels of Ace on the cell surface in the latter phases of growth. Furthermore, we observed that, in addition to fsrB mutants, other strains identified as deficient in GelE activity also demonstrated a similar phenotype. Additional experiments demonstrated the GelE-dependent cleavage of Ace from the surface of E. faecalis , confirming that GelE specifically reduces Ace cell surface display. In addition, disruption of the Fsr system or G...
International Journal of Molecular Sciences, 2021
The primary function of the skin is that of a physical barrier against the environment and divers... more The primary function of the skin is that of a physical barrier against the environment and diverse pathogens; therefore, its integrity is essential for survival. Skin regeneration depends on multiple stem cell compartments within the epidermis, which, despite their different transcriptional and proliferative capacity, as well as different anatomical location, fall under the general term of skin stem cells (SSCs). Skin wounds can normally heal without problem; however, some diseases or extensive damage may delay or prevent healing. Non-healing wounds represent a serious and life-threatening scenario that may require advanced therapeutic strategies. In this regard, increased focus has been directed at SSCs and their role in wound healing, although emerging therapeutical approaches are considering the use of other stem cells instead, such as mesenchymal stem cells (MSCs). Given its extensive and broad nature, this review supplies newcomers with an introduction to SSCs, wound healing, a...
Journal of Cellular and Molecular Medicine
This is an open access article under the terms of the Creat ive Commo ns Attri bution License, wh... more This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
International journal of oncology, 2012
The carcinogenic potential of HPV infections is based on the integration and constitutive express... more The carcinogenic potential of HPV infections is based on the integration and constitutive expression of the E6 and E7 genes which inhibit the p53 and Rb tumor suppressor proteins. In normal cells, Mdm2 regulates p53 in a negative feedback loop, and although Mdm2 is apparently functional in HPV-infected cells, E6 is the protein responsible for repressing p53 replacing Mdm2 function. The role of Mdm2 in HPV-positive cells is still elusive. In this study, Mdm2 was knocked down in an HPV-positive cervical cancer cell line; as a result we found downregulation of the expression of E6 and E7 and p53 upregulation.
Experimental and Therapeutic Medicine, May 1, 2012
Vitiligo is a skin disease characterized by depigmentation. Its etiopathogenesis is unclear, but ... more Vitiligo is a skin disease characterized by depigmentation. Its etiopathogenesis is unclear, but it has been associated with autoimmune processes. Gene polymorphisms in the tumor necrosis factor-α (TNF-α) have been associated with several imflammatory diseases. In particular, the-308G/A polymorphism in the gene promoter region has been reported to be associated with increased plasma levels of TNF-α and with an increased risk to develop autoimmune diseases. To date, this polymorphism has not been associated with vitiligo. ...
Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia, Jan 18, 2013
A biological scaffold from extracellular matrix can be produced by a variety of decellularization... more A biological scaffold from extracellular matrix can be produced by a variety of decellularization methods whose caveat consists in efficiently eliminating cells from the treated tissue. This scaffold can be used in diverse applications for tissue engineering and organ regeneration. Preservation of the extracellular matrix ultrastructure is highly desirable because of its unique architecture, contained growth factors and decreased immunological response. All of these properties provide attachment sites and adequate environment for cells colonizing this scaffold, reconstituting the decellularized organ. This review briefly describes chemical decellularization methods, evaluation of these protocols and the role of ECM in tissue engineering. Chemical decellularization is an often used method for scaffold preparation and makes possible a well-preserved three dimensional structure of extracellular matrix.
International Journal of Molecular Sciences, 2014
Hair follicle morphogenesis depends on Wnt, Shh, Notch, BMP and other signaling pathways interpla... more Hair follicle morphogenesis depends on Wnt, Shh, Notch, BMP and other signaling pathways interplay between epithelial and mesenchymal cells. The Wnt pathway plays an essential role during hair follicle induction, Shh is involved in morphogenesis and late stage differentiation, Notch signaling determines stem cell fate while BMP is involved in cellular differentiation. The Wnt pathway is considered to be the master regulator during hair follicle morphogenesis. Wnt signaling proceeds through EDA/EDAR/NF-κB signaling. NF-κB regulates the Wnt pathway and acts as a signal mediator by upregulating the expression of Shh ligand. Signal crosstalk between epithelial and mesenchymal cells takes place mainly through primary cilia. Primary cilia formation is initiated with epithelial laminin-511 interaction with dermal β-1 integrin, which also upregulates expression of downstream effectors of Shh pathway in dermal lineage. PDGF signal transduction essential for crosstalk is mediated through epithelial PDGF-A and PDGFRα expressed on the primary cilia. Dermal Shh and PDGF signaling up-regulates dermal noggin expression; noggin is a potent inhibitor of BMP signaling which helps in counteracting BMP mediated β-catenin inhibition. This interplay of signaling between the epithelial and dermal lineage helps in epithelial Shh signal amplification. The dermal Wnt pathway helps in upregulation OPEN ACCESS