Luiz Carlos Alves - Academia.edu (original) (raw)

Papers by Luiz Carlos Alves

Reactive & Functional Polymers, 2008

A semi-interpenetrated polymer network of posiloxane and polyvinyl alcohol (POS-PVA) was synthesi... more A semi-interpenetrated polymer network of posiloxane and polyvinyl alcohol (POS-PVA) was synthesized through solgel process in the form of discs and used as solid support for antibody immobilization. POS-PVA discs presented a protein loading capacity of approximately 210 lg/disc and can covalently bind an anti-S100 protein antibody via glutaraldehyde. The POS-PVA matrix network resulted in hard and spherical discs of uniform size, diameter of 4.0 mm 2 . Scanning electron microscopy (SEM) analysis revealed a uniformly formed porous network. The SEM and infrared absorption spectra confirmed that the activation with glutaraldehyde do not alter the POS-PVA discs structure is similar to that discs before antibody immobilization. The elemental analysis of discs (POS-PVA + Glutaraldehyde + Antibody) was evaluated and the following constitution was obtained (%): carbon (6.57), nitrogen (0.67), hydrogen (4.25) and sulphur (0.32), suggesting that the antibody completely fixed after adsorption. The shelf-life of discs was performed at six months and showed better protein loading capacity by POS-PVA discs incubated at 4°C and hydrated with phosphate buffer solution when compared with same discs exposed to different environment store (room temperature and dry). In conclusion, microarrays of antibody immobilized on POS-PVA support demonstrated sensitivity, its antibody covalent immobilization and discs synthesis involves simple steps and the reagents employed are inexpensive. Hence the present semi-interpenetrating polymer network can be used as an alternative of solid support for sera assays. Published by Elsevier Ltd.

Journal of Parasitology, 2000

Roller mutants of Caenorhabditis elegans rotate around their long axis and move in circular paths... more Roller mutants of Caenorhabditis elegans rotate around their long axis and move in circular paths. Isolation and sequence of the rol-6 gene of C. elegans have shown that it encodes a cuticle collagen. In this paper, we describe the morphological alterations seen in the cuticle of the right roller mutant rol-6 (su1006) at the ultrastructural level. Deep-etched replica analyses showed that the honeycomb elements, fibers organized in a pentagonal fashion above the fishbone fibrous layer, completely fill the intermediate layer, which is observed to be largely empty spaces in the wild-type strain. The honeycomb fibers appear to connect the cortical and basal regions of the mutant cuticle. These fibers are likely to be involved in generating the helical twist of the mutant animals. Deep-etched replicas also revealed a delicate network of filaments on the nematode surface.

Science, 2010

Mosquito midgut invasion by ookinetes of the malaria parasite Plasmodium disrupts the barriers th... more Mosquito midgut invasion by ookinetes of the malaria parasite Plasmodium disrupts the barriers that normally prevent the gut microbiota from coming in direct contact with epithelial cells. This triggers a long-lived response characterized by increased abundance of granulocytes, a subpopulation of hemocytes that circulates in the insect’s hemocoel, and enhanced immunity to bacteria that indirectly reduces survival of Plasmodium parasites upon reinfection. In mosquitoes, differentiation of hemocytes was necessary and sufficient to confer innate immune memory.

Chemical & Pharmaceutical Bulletin, 2009

The synthesis of 3-(3-aryl-1,2,4-oxadiazol-5-yl)propionic acids from arylamidoximes and succinic ... more The synthesis of 3-(3-aryl-1,2,4-oxadiazol-5-yl)propionic acids from arylamidoximes and succinic anhydride under focused microwave irradiation conditions is described. The new synthetic method furnished the desired products in 2-3 min and good yields. Furthermore, the previously complicated purification procedure has been simplified in a manner which is quick, eco-friendly and cost-effective. Larvicidal bioassay and fungal growth inhibitory tests were performed using several 3-(3-aryl-1,2,4-oxadiazol-5-yl)propionic acids. These acids presented strong larvicidal activity against L4 larvae of Aedes aegypti. The results suggest that larvicidal activity might be correlated with the presence of electron-withdrawing substituents in the para position of the phenyl ring except the fluorine atom. The alterations observed in the larvae spiracular valves of the siphon and anal papillae by 1,2,4-oxadiazoles in the larvicidal bioassay are responsible for larvae's death. Furthermore, all acids inhibited the fungal growth of five different types of fungi, viz., Fusarium solani, F. oxysporum, F. moniliforme, F. decemcellulare and F. lateritium in a preliminary evaluation. Both of these activities are being disclosed for the first time for 1,2,4-oxadiazole-5-yl ring linked at C-3 of propionic acid.

Current Microbiology, 2011

The aim of this study was to determine the prevalence of the bla SHV gene in Klebsiella pneumonia... more The aim of this study was to determine the prevalence of the bla SHV gene in Klebsiella pneumoniae isolates from hospital and community infections and from the normal microbiota of healthy individuals in Recife, PE, Brazil. Fifty-two K. pneumoniae isolates were analyzed regarding the presence of the bla SHV gene, using PCR, and eight isolates were analyzed by DNA sequencing. This gene was detected in 16 isolates from hospital infections, four from community infections, and nine from the normal microbiota. This was the first study to find the bla SHV gene in K. pneumoniae isolates from the normal microbiota. Through DNA sequencing of eight K. pneumoniae isolates from hospital and community infections, with a resistance phenotype indicative of extended-spectrum β-lactamase production, a new SHV variant named SHV-122 was found. We also detected the presence of bla SHV-1, bla SHV-11, bla SHV-28, and bla SHV-108. The results show that in Recife, Brazil, K. pneumoniae isolates that presented resistance to oxyimino-β-lactams had high prevalence and diversity of the bla SHV gene. We also conclude that there was a high presence of the bla SHV gene among isolates from the normal microbiota of healthy individuals.

Journal of Parasitology, 2003

Bacillus cereus Tspores is described. Ultrathin cryosectiom of B. cereus Tspores were labeled wit... more Bacillus cereus Tspores is described. Ultrathin cryosectiom of B. cereus Tspores were labeled with rabbit anti-B. cereus T spore serum and protien A-gold conjugate, and viewed in a transmission electron microscope. Antigens were located throughout the spore exosporium and also in the spore coat and protoplast. The higher density of gold particles in the exosporium indicates that the exosporium is very antigenic and was the major antigen when whole, formalin-treated, spores were injected into rabbits. The presence of label in the interior structure suggests spores may have been degraded by the animal upon injection, permitting exposure of interior antigens. 'Paper number FSR93-32 of the Journal Series of the Department of Food Science, North Carolina State University, Raleigh, NC 27695-7624. The use of trade names in this paper does not imply endorsement by the North Carolina Agricultural Research Service nor criticism of similar ones not mentioned.

Micron, 2003

Light microscopy analyses of microfilariae of Wuchereria bancrofti treated with DEC revealed a st... more Light microscopy analyses of microfilariae of Wuchereria bancrofti treated with DEC revealed a striking loss of the microfilarial sheath. However, no effect was observed on microfilariae of Litomosoides chagasfilhoi treated with DEC. For quantitative analyses microfilariae of W. bancrofti were processed for SEM. Controls, which have not received DEC, had 29.8% of exsheathed microfilariae. Conversely, the number of exsheathed microfilariae increased as increased DEC concentrations: 5 microg/ml (75.9%), 10 microg/ml (80.1%), and 50 microg/ml (87.7%). After DEC treatment some of sheathed microfilariae showed a wrinkled surface, and in some microfilariae, sheaths were observed being liberated almost intact from the larvae surface. But, frequently residues of the lost sheath over the surface were also observed. No damage was observed in the microfilariae cuticle. The present work shows quantitative data on the loss of the microfilarial sheath of W. bancrofti after treatment with DEC. Since no loss of microfilarial sheath was observed in microfilariae of L. chagasfilhoi submitted to the same conditions, DEC may present different mechanisms of action for distinct filarial species.

Micron, 2005

This paper is the first descriptive review of hemolymph cell types in the circulation of the tara... more This paper is the first descriptive review of hemolymph cell types in the circulation of the tarantula spider Lasiodora sp. These animals are more long-lived than other arthropods, and may live for approximately twenty years. Such remarkable longevity may result from a highly successful immune system, which in turn is directly correlated with hemocyte function. Since the literature on the genus Lasiodora sp. is limited, the main goal of the present study was to identify the different cell types by optical and transmission microscope. Six hemocyte types were characterized and called prohemocyte, granulocyte type I, granulocyte type II, spherulocyte, oenocytoid and plasmatocyte. Prohemocytes presented a large nucleus, elongated granulocytes type I showed the nucleus with the same cell format, elliptical granulocytes type II showed the central nucleus of identical shape, spherulocytes exhibited the nucleus filling almost the whole cell, oval oenocytoids showed eccentric nucleus and less dense cytoplasm, and irregular plasmatocytes showed a nucleus and no granules in cytoplasm. These polymorphic granulocytes presented a round, elongated, elliptical, oval or irregular profile with large and varied numbers of granules, except for plasmatocytes, that were agranular. Different densities and different concentrations of these granules were found at the periphery of the cell. The possible reasons and implications of differences and similarities between arthropods hemocytes are discussed. It can be concluded that there are six cell types in Lasiodora sp. This study is of the first step in the elucidation of the role these cells play in the circulatory and immune system in spiders.

Medical and Veterinary Entomology, 2007

Haemocytes circulating in the haemolymph protect insects against pathogens that enter the haemoco... more Haemocytes circulating in the haemolymph protect insects against pathogens that enter the haemocoel. Changes in haemocyte morphology and differences in haemocyte counts during the immune response of Culex quinquefasciatus Say (Diptera: Culicidae) to microfilariae of Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae) were investigated in the present study. The mean number of total haemocytes was significantly elevated in infected mosquitoes ( P < 0.001), reaching a peak on the third day post-infection. Differential counts show that mean numbers of prohaemocytes, plasmatocytes, granular cells and oenocytoids increased significantly after infection with microfilariae granulocytes compared to the control and näive groups of Cx. quinquefasciatus ( P < 0.05). Changes in proportional counts of haemocytes were also analysed in haemolymph perfusates of Cx. quinquefasciatus infected with W. bancrofti . On the first day post-infection, infected mosquitoes showed an increase in the proportion of prohaemocytes (18.8% compared to 9.6% for the control) and of oenocytoids (7.1% compared to 4.7% control); however, they exhibited lower levels of plasmatocytes (36.6% compared to 42.1% control) and granular cells (36.1% compared to 41.4% control). On day 14 post-infection, similar changes were observed for these haemocyte types, except that the proportion of granular cells was significantly greater than the control (41.2% compared to 31.3% control). Although an enhancement of prohaemocyte numbers was observed, this cellular type did not show any ultrastructural alteration. On the other hand, granular cells, plasmatocytes and oenocytoids presented morphological alterations indicative of innate immunological activation in mosquitoes infected with W. bancrofti .

Micron, 2005

Topografia PUC/PR Engenharia Civil -1-1. Topografia

Topografia PUC/PR Engenharia Civil -1-1. Topografia

Reactive & Functional Polymers, 2008

A semi-interpenetrated polymer network of posiloxane and polyvinyl alcohol (POS-PVA) was synthesi... more A semi-interpenetrated polymer network of posiloxane and polyvinyl alcohol (POS-PVA) was synthesized through solgel process in the form of discs and used as solid support for antibody immobilization. POS-PVA discs presented a protein loading capacity of approximately 210 lg/disc and can covalently bind an anti-S100 protein antibody via glutaraldehyde. The POS-PVA matrix network resulted in hard and spherical discs of uniform size, diameter of 4.0 mm 2 . Scanning electron microscopy (SEM) analysis revealed a uniformly formed porous network. The SEM and infrared absorption spectra confirmed that the activation with glutaraldehyde do not alter the POS-PVA discs structure is similar to that discs before antibody immobilization. The elemental analysis of discs (POS-PVA + Glutaraldehyde + Antibody) was evaluated and the following constitution was obtained (%): carbon (6.57), nitrogen (0.67), hydrogen (4.25) and sulphur (0.32), suggesting that the antibody completely fixed after adsorption. The shelf-life of discs was performed at six months and showed better protein loading capacity by POS-PVA discs incubated at 4°C and hydrated with phosphate buffer solution when compared with same discs exposed to different environment store (room temperature and dry). In conclusion, microarrays of antibody immobilized on POS-PVA support demonstrated sensitivity, its antibody covalent immobilization and discs synthesis involves simple steps and the reagents employed are inexpensive. Hence the present semi-interpenetrating polymer network can be used as an alternative of solid support for sera assays. Published by Elsevier Ltd.

Journal of Parasitology, 2000

Roller mutants of Caenorhabditis elegans rotate around their long axis and move in circular paths... more Roller mutants of Caenorhabditis elegans rotate around their long axis and move in circular paths. Isolation and sequence of the rol-6 gene of C. elegans have shown that it encodes a cuticle collagen. In this paper, we describe the morphological alterations seen in the cuticle of the right roller mutant rol-6 (su1006) at the ultrastructural level. Deep-etched replica analyses showed that the honeycomb elements, fibers organized in a pentagonal fashion above the fishbone fibrous layer, completely fill the intermediate layer, which is observed to be largely empty spaces in the wild-type strain. The honeycomb fibers appear to connect the cortical and basal regions of the mutant cuticle. These fibers are likely to be involved in generating the helical twist of the mutant animals. Deep-etched replicas also revealed a delicate network of filaments on the nematode surface.

Science, 2010

Mosquito midgut invasion by ookinetes of the malaria parasite Plasmodium disrupts the barriers th... more Mosquito midgut invasion by ookinetes of the malaria parasite Plasmodium disrupts the barriers that normally prevent the gut microbiota from coming in direct contact with epithelial cells. This triggers a long-lived response characterized by increased abundance of granulocytes, a subpopulation of hemocytes that circulates in the insect’s hemocoel, and enhanced immunity to bacteria that indirectly reduces survival of Plasmodium parasites upon reinfection. In mosquitoes, differentiation of hemocytes was necessary and sufficient to confer innate immune memory.

Chemical & Pharmaceutical Bulletin, 2009

The synthesis of 3-(3-aryl-1,2,4-oxadiazol-5-yl)propionic acids from arylamidoximes and succinic ... more The synthesis of 3-(3-aryl-1,2,4-oxadiazol-5-yl)propionic acids from arylamidoximes and succinic anhydride under focused microwave irradiation conditions is described. The new synthetic method furnished the desired products in 2-3 min and good yields. Furthermore, the previously complicated purification procedure has been simplified in a manner which is quick, eco-friendly and cost-effective. Larvicidal bioassay and fungal growth inhibitory tests were performed using several 3-(3-aryl-1,2,4-oxadiazol-5-yl)propionic acids. These acids presented strong larvicidal activity against L4 larvae of Aedes aegypti. The results suggest that larvicidal activity might be correlated with the presence of electron-withdrawing substituents in the para position of the phenyl ring except the fluorine atom. The alterations observed in the larvae spiracular valves of the siphon and anal papillae by 1,2,4-oxadiazoles in the larvicidal bioassay are responsible for larvae's death. Furthermore, all acids inhibited the fungal growth of five different types of fungi, viz., Fusarium solani, F. oxysporum, F. moniliforme, F. decemcellulare and F. lateritium in a preliminary evaluation. Both of these activities are being disclosed for the first time for 1,2,4-oxadiazole-5-yl ring linked at C-3 of propionic acid.

Current Microbiology, 2011

The aim of this study was to determine the prevalence of the bla SHV gene in Klebsiella pneumonia... more The aim of this study was to determine the prevalence of the bla SHV gene in Klebsiella pneumoniae isolates from hospital and community infections and from the normal microbiota of healthy individuals in Recife, PE, Brazil. Fifty-two K. pneumoniae isolates were analyzed regarding the presence of the bla SHV gene, using PCR, and eight isolates were analyzed by DNA sequencing. This gene was detected in 16 isolates from hospital infections, four from community infections, and nine from the normal microbiota. This was the first study to find the bla SHV gene in K. pneumoniae isolates from the normal microbiota. Through DNA sequencing of eight K. pneumoniae isolates from hospital and community infections, with a resistance phenotype indicative of extended-spectrum β-lactamase production, a new SHV variant named SHV-122 was found. We also detected the presence of bla SHV-1, bla SHV-11, bla SHV-28, and bla SHV-108. The results show that in Recife, Brazil, K. pneumoniae isolates that presented resistance to oxyimino-β-lactams had high prevalence and diversity of the bla SHV gene. We also conclude that there was a high presence of the bla SHV gene among isolates from the normal microbiota of healthy individuals.

Journal of Parasitology, 2003

Bacillus cereus Tspores is described. Ultrathin cryosectiom of B. cereus Tspores were labeled wit... more Bacillus cereus Tspores is described. Ultrathin cryosectiom of B. cereus Tspores were labeled with rabbit anti-B. cereus T spore serum and protien A-gold conjugate, and viewed in a transmission electron microscope. Antigens were located throughout the spore exosporium and also in the spore coat and protoplast. The higher density of gold particles in the exosporium indicates that the exosporium is very antigenic and was the major antigen when whole, formalin-treated, spores were injected into rabbits. The presence of label in the interior structure suggests spores may have been degraded by the animal upon injection, permitting exposure of interior antigens. 'Paper number FSR93-32 of the Journal Series of the Department of Food Science, North Carolina State University, Raleigh, NC 27695-7624. The use of trade names in this paper does not imply endorsement by the North Carolina Agricultural Research Service nor criticism of similar ones not mentioned.

Micron, 2003

Light microscopy analyses of microfilariae of Wuchereria bancrofti treated with DEC revealed a st... more Light microscopy analyses of microfilariae of Wuchereria bancrofti treated with DEC revealed a striking loss of the microfilarial sheath. However, no effect was observed on microfilariae of Litomosoides chagasfilhoi treated with DEC. For quantitative analyses microfilariae of W. bancrofti were processed for SEM. Controls, which have not received DEC, had 29.8% of exsheathed microfilariae. Conversely, the number of exsheathed microfilariae increased as increased DEC concentrations: 5 microg/ml (75.9%), 10 microg/ml (80.1%), and 50 microg/ml (87.7%). After DEC treatment some of sheathed microfilariae showed a wrinkled surface, and in some microfilariae, sheaths were observed being liberated almost intact from the larvae surface. But, frequently residues of the lost sheath over the surface were also observed. No damage was observed in the microfilariae cuticle. The present work shows quantitative data on the loss of the microfilarial sheath of W. bancrofti after treatment with DEC. Since no loss of microfilarial sheath was observed in microfilariae of L. chagasfilhoi submitted to the same conditions, DEC may present different mechanisms of action for distinct filarial species.

Micron, 2005

This paper is the first descriptive review of hemolymph cell types in the circulation of the tara... more This paper is the first descriptive review of hemolymph cell types in the circulation of the tarantula spider Lasiodora sp. These animals are more long-lived than other arthropods, and may live for approximately twenty years. Such remarkable longevity may result from a highly successful immune system, which in turn is directly correlated with hemocyte function. Since the literature on the genus Lasiodora sp. is limited, the main goal of the present study was to identify the different cell types by optical and transmission microscope. Six hemocyte types were characterized and called prohemocyte, granulocyte type I, granulocyte type II, spherulocyte, oenocytoid and plasmatocyte. Prohemocytes presented a large nucleus, elongated granulocytes type I showed the nucleus with the same cell format, elliptical granulocytes type II showed the central nucleus of identical shape, spherulocytes exhibited the nucleus filling almost the whole cell, oval oenocytoids showed eccentric nucleus and less dense cytoplasm, and irregular plasmatocytes showed a nucleus and no granules in cytoplasm. These polymorphic granulocytes presented a round, elongated, elliptical, oval or irregular profile with large and varied numbers of granules, except for plasmatocytes, that were agranular. Different densities and different concentrations of these granules were found at the periphery of the cell. The possible reasons and implications of differences and similarities between arthropods hemocytes are discussed. It can be concluded that there are six cell types in Lasiodora sp. This study is of the first step in the elucidation of the role these cells play in the circulatory and immune system in spiders.

Medical and Veterinary Entomology, 2007

Haemocytes circulating in the haemolymph protect insects against pathogens that enter the haemoco... more Haemocytes circulating in the haemolymph protect insects against pathogens that enter the haemocoel. Changes in haemocyte morphology and differences in haemocyte counts during the immune response of Culex quinquefasciatus Say (Diptera: Culicidae) to microfilariae of Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae) were investigated in the present study. The mean number of total haemocytes was significantly elevated in infected mosquitoes ( P < 0.001), reaching a peak on the third day post-infection. Differential counts show that mean numbers of prohaemocytes, plasmatocytes, granular cells and oenocytoids increased significantly after infection with microfilariae granulocytes compared to the control and näive groups of Cx. quinquefasciatus ( P < 0.05). Changes in proportional counts of haemocytes were also analysed in haemolymph perfusates of Cx. quinquefasciatus infected with W. bancrofti . On the first day post-infection, infected mosquitoes showed an increase in the proportion of prohaemocytes (18.8% compared to 9.6% for the control) and of oenocytoids (7.1% compared to 4.7% control); however, they exhibited lower levels of plasmatocytes (36.6% compared to 42.1% control) and granular cells (36.1% compared to 41.4% control). On day 14 post-infection, similar changes were observed for these haemocyte types, except that the proportion of granular cells was significantly greater than the control (41.2% compared to 31.3% control). Although an enhancement of prohaemocyte numbers was observed, this cellular type did not show any ultrastructural alteration. On the other hand, granular cells, plasmatocytes and oenocytoids presented morphological alterations indicative of innate immunological activation in mosquitoes infected with W. bancrofti .

Micron, 2005

Topografia PUC/PR Engenharia Civil -1-1. Topografia

Topografia PUC/PR Engenharia Civil -1-1. Topografia