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1.
Actas dermo-sifiliogr. (Ed. impr.) ; 111(8): 629-638, oct. 2020.
Article in Spanish | IBECS | ID: ibc-188364

ABSTRACT

BACKGROUND AND OBJECTIVES: Spain is in a situation of indefinite lockdown due to the ongoing coronavirus disease 2019 (COVID-19) pandemic. One of the consequences of this lockdown is delays in medical and surgical procedures for common diseases. The aim of this study was to model the impact on survival of tumor growth caused by such delays in patients with squamous cell carcinoma (SCC) and melanoma. MATERIAL AND METHODS: Multicenter, retrospective, observational cohort study. We constructed an exponential growth model for both SCC and melanoma to estimate tumor growth between patient-reported onset and surgical excision at different time points. RESULTS: Data from 200 patients with SCC of the head and neck and 1000 patients with cutaneous melanoma were included. An exponential growth curve was calculated for each tumor type and we estimated tumor size after 1, 2, and 3 months of potential surgical delay. The proportion of patients with T3 SCC (diameter > 4 cm or thickness > 6 mm) increased from 41.5% (83 patients) in the initial study group to an estimated 58.5%, 70.5%, and 72% after 1, 2, and 3 months of delay. Disease-specific survival at 2, 5, and 10 years in patients whose surgery was delayed by 3 months decreased by 6.2%, 8.2%, and 5.2%, respectively. The proportion of patients with ultrathick melanoma (> 6 mm) increased from 6.9% in the initial study group to 21.9%, 30.2%, and 30.2% at 1, 2, and 3 months. Five-and 10-year disease-specific survival both decreased by 14.4% in patients treated after a potential delay of 3 months. CONCLUSIONS: In the absence of adequate diagnosis and treatment of SCC and melanoma in the current lockdown situation in Spain, we can expect tosee to a considerable increase in large and thick SCCs and melanomas. Efforts must be taken to encourage self-examination and facilitate access to dermatologists in order to prevent further delays


ANTECEDENTES Y OBJETIVOS: La pandemia del coronavirus COVID-19 ha provocado un confinamiento indefinido. Una posible consecuencia de esta situación es un retraso en los procedimientos asistenciales de las patologías comunes. El objetivo de este estudio es estimar el hipotético impacto en la supervivencia que tendría el aumento del tamaño tanto para los carcinomas de células escamosas (CCE) como de los melanomas. MATERIAL Y MÉTODO: Estudio observacional retrospectivo de cohortes multicéntrico. Se desarrolló un modelo de crecimiento exponencial para cada tumor basado en el tiempo de evolución que refiere el paciente. RESULTADOS: Se incluyeron un total de 200 pacientes con CCEs localizados en la cabeza y el cuello y 1000 pacientes con melanoma cutáneo. Se calculó una curva de crecimiento exponencial para cada tumor y se estimó el tamaño del tumor tras 1, 2 y 3 mes tras el diagnóstico. En la muestra, los CCE mayores de 4 cm o > 6 mm de grosor (definidos como T3) pasaron de 83 (41.5%) en el grupo de estudio real a una estimación de 58,5%, 70,5% y 72% tras 1, 2 y 3 meses de retraso quirúrgico estimado. Se estimó una disminución de la supervivencia específica de enfermedad (SEE) de un 6,2%, 8,2% y 5,2% a los 2, 5 y 10 años, respectivamente, tras tres meses de retraso. Para los melanomas, los melanomas ultragruesos (> 6 mm) pasaron del 6,9% en el grupo de estudio al 21,9%, 30,2% y 30,2% tras 1,2 y 3 meses de demora. La SEE a los 5 y 10 años del grupo de estudio descendió un 14,4% en ambos tiempos. CONCLUSIONES: En ausencia de un adecuado diagnóstico y tratamiento de los pacientes con CCE y melanoma en la actual situación de confinamiento en España, podemos llegar a asistir a un considerable aumento de los casos de CCE y melanomas gruesos y de gran tamaño. Se deben fomentar los esfuerzos para promocionar la autoexploración y facilitar el acceso a los dermatólogos para no aumentar la demora de estos pacientes. Palabras clave: melanoma, pronóstico, diagnóstico precoz, carcinoma de células escamosas cutáneo, COVID-19, confinamiento


Subject(s)
Humans , Male , Female , Aged , Aged, 80 and over , Neoplasms, Squamous Cell/mortality , Melanoma/mortality , Skin Neoplasms/mortality , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Betacoronavirus , Pandemics , Quarantine , Survival Analysis , Retrospective Studies , Cohort Studies
2.
Actas Dermosifiliogr (Engl Ed) ; 111(8): 629-638, 2020 Oct.
Article in Spanish | MEDLINE | ID: mdl-32513393

ABSTRACT

BACKGROUND AND OBJECTIVES: Spain is in a situation of indefinite lockdown due to the ongoing coronavirus disease 2019 (COVID-19) pandemic. One of the consequences of this lockdown is delays in medical and surgical procedures for common diseases. The aim of this study was to model the impact on survival of tumor growth caused by such delays in patients with squamous cell carcinoma (SCC) and melanoma. MATERIAL AND METHODS: Multicenter, retrospective, observational cohort study. We constructed an exponential growth model for both SCC and melanoma to estimate tumor growth between patient-reported onset and surgical excision at different time points. RESULTS: Data from 200 patients with SCC of the head and neck and 1000 patients with cutaneous melanoma were included. An exponential growth curve was calculated for each tumor type and we estimated tumor size after 1, 2, and 3 months of potential surgical delay. The proportion of patients with T3 SCC (diameter >4cm or thickness >6 mm) increased from 41.5% (83 patients) in the initial study group to an estimated 58.5%, 70.5%, and 72% after 1, 2, and 3 months of delay. Disease-specific survival at 2, 5, and 10 years in patients whose surgery was delayed by 3 months decreased by 6.2%, 8.2%, and 5.2%, respectively. The proportion of patients with ultrathick melanoma (>6 mm) increased from 6.9% in the initial study group to 21.9%, 30.2%, and 30.2% at 1, 2, and 3 months. Five- and 10-year disease-specific survival both decreased by 14.4% in patients treated after a potential delay of 3 months. CONCLUSIONS: In the absence of adequate diagnosis and treatment of SCC and melanoma in the current lockdown situation in Spain, we can expect to see to a considerable increase in large and thick SCCs and melanomas. Efforts must be taken to encourage self-examination and facilitate access to dermatologists in order to prevent further delays.


Subject(s)
Betacoronavirus , Carcinoma, Squamous Cell/pathology , Coronavirus Infections/epidemiology , Head and Neck Neoplasms/pathology , Melanoma/pathology , Pneumonia, Viral/epidemiology , Skin Neoplasms/pathology , Tumor Burden , Age Factors , Algorithms , COVID-19 , Carcinoma, Squamous Cell/mortality , Delayed Diagnosis/adverse effects , Delayed Diagnosis/statistics & numerical data , Female , Head and Neck Neoplasms/mortality , Health Services Accessibility , Humans , Male , Melanoma/mortality , Pandemics , Public Health Surveillance/methods , Quarantine , Retrospective Studies , SARS-CoV-2 , Sex Factors , Skin Neoplasms/mortality , Spain/epidemiology , Time Factors , Time-to-Treatment
3.
ACS Appl Mater Interfaces ; 12(38): 42622-42633, 2020 Sep 23.
Article in English | MEDLINE | ID: mdl-32568508

ABSTRACT

Cu-based metal-organic framework (MOF) microdevices are applied in sampling and preconcentration of nerve agents (NAs) diluted in gaseous streams. An in situ electrochemical-assisted synthesis of a Cu-benzene-1,3,5-tricarboxylate (BTC) thick film is carried out to functionalize a Cu-modified glass substrate. This simple, rapid, reproducible, and easy-to-integrate MOF synthesis approach enables the microfabrication of functional micro-preconcentrators with a large Brunauer-Emmett-Teller (BET) surface area (above 2000 cm2) and an active pore volume (above 90 nL) for the efficient adsorption of nerve agent molecules along the microfluidic channel 2.5 cm in length. The equilibrium adsorption capacity of the bulk material has been characterized through thermogravimetric analysis after exposure to controlled atmospheres of a sarin gas surrogate, dimethyl methylphosphonate (DMMP), in both dry and humid conditions (30% RH at 293 K). Breakthrough tests at the ppm level (162 mg/m3) reveal equilibrium adsorption capacities up to 691 mg/g. The preconcentration performance of such µ-devices when dealing with highly diluted surrogate atmosphere, i.e., 520 ppbV (2.6 mg/m3) at 298 K, leads to preconcentration coefficients up to 171 for sample volume up to 600 STP cm3. We demonstrate the potentialities of Cu-BTC micro-preconcentrators as smart first responder tools for "on-field" detection of nerve agents in the gas phase at relevant conditions.


Subject(s)
Copper/chemistry , Metal-Organic Frameworks/chemistry , Nerve Agents/analysis , Tricarboxylic Acids/chemistry , Adsorption , Particle Size , Potentiometry , Surface Properties
4.
An. pediatr. (2003, Ed. impr.) ; 78(4): 268-268[e1-e7], abr. 2013. tab, graf
Article in Spanish | IBECS | ID: ibc-110396

ABSTRACT

En España, hasta el año 2010 se ha prestado poca atención a los adolescentes con cáncer. En el año 2011 se crea el Comité de adolescentes con cáncer dentro de la Sociedad Española de Onco-Hematología Pediátrica (SEHOP), con el objetivo de cubrir las demandas y necesidades de estos pacientes. Con esta encuesta nacional se pretende obtener una fotografía de la situación actual de los adolescentes con cáncer en las unidades de hemato-oncología pediátrica españolas. Se ha realizado una encuesta, enviada vía email a 41 unidades de hemato-oncología pediátrica españolas. Se incluyen preguntas acerca de la epidemiología, el tratamiento, el abordaje psicosocial, las instalaciones y el seguimiento de estos pacientes. Un total de 40 unidades respondieron a la encuesta (98%). El 56% de las unidades trata a pacientes por encima de los 14 años, pero solo el 36% hasta los 18 años. Solo el 25,5% de las unidades trata más de 40 casos nuevos cada año. El porcentaje de los pacientes entre 14 y 18 años del total es menor del 10% en la mayoría de las unidades (77%).El 30,8 y el 48,7% de las unidades pediátricas tratan los adolescentes con hemopatías malignas y con tumores sólidos, respectivamente. El resto de los adolescentes con estas afecciones son tratados por los servicios de adultos. Solo existe una unidad en España que tenga un médico dedicado a la enfermedad oncológica del adolescente y solo hay 2 unidades que tengan una sala específica para adolescentes. Esta encuesta demuestra que la mayoría de los adolescentes con cáncer en España son tratados por especialistas de adultos, a pesar de que la supervivencia de estos pacientes es mayor cuando se utilizan protocolos pediátricos para su tratamiento. La mayoría de las unidades no tienen instalaciones ni personal especialmente dedicados a este grupo de pacientes. La SEHOP está aunando esfuerzos para mejorar tanto la supervivencia como la calidad del tratamiento de estos pacientes(AU)


Little attention was paid to adolescents with Cancer in Spain up to 2010. In 2011 an “Adolescents with Cancer Committee” was established by the Spanish Society of Pediatric Hemato-Oncology (SEHOP) to care for the needs of these patients. The aim of this national survey was to outline the present situation of adolescents with cancer in Spanish Pediatric Hemato-Oncology units. A web based survey assessed institutional management of adolescents with cancer. The survey was personally sent to one member of the staff of each Pediatric Hemato-Oncology unit in Spain. It included questions about epidemiology, management, psycho-social coverage, specific facilities, and follow up of these patients. A total of 40 institutions out of 41 responded to the survey (overall response rate 98%). Fifty-six percent of the institutions had patients over 14, but only 36% of the institutions treated patients up to 18 years old. Only 25.6% of the units have more than 40 new pediatric cases every year. The percentage of patients between 14 and 18 years of age is below 10% in most of the units (77%).The survey shows that most adolescents with cancer in Spain between 14 and 18 years of age are treated by adult oncologists. Most pediatric institutions still do not have specific facilities and psychosocial support for adolescents. The SEHOP is working hard in order to improve the quality of cancer care, and the quality of survival of this population. In 30.8% and 48.7% of the institutions, pediatric hemato-oncologists treat adolescents with hematological and solid tumors, respectively. The rest of the patients are seen by adult oncologists. There is only one institution that has a physician specifically dedicated to adolescent patients, and only two units have a “teenager's room”. Only 2 units have a psychologist specifically trained to treat adolescents with cancer(AU)


Subject(s)
Humans , Male , Female , Adolescent , Neoplasms/epidemiology , Oncology Service, Hospital/statistics & numerical data , 24419 , Survival Rate
5.
An Pediatr (Barc) ; 78(4): 268.e1-7, 2013 Apr.
Article in Spanish | MEDLINE | ID: mdl-23201346

ABSTRACT

Little attention was paid to adolescents with Cancer in Spain up to 2010. In 2011 an "Adolescents with Cancer Committee" was established by the Spanish Society of Pediatric Hemato-Oncology (SEHOP) to care for the needs of these patients. The aim of this national survey was to outline the present situation of adolescents with cancer in Spanish Pediatric Hemato-Oncology units. A web based survey assessed institutional management of adolescents with cancer. The survey was personally sent to one member of the staff of each Pediatric Hemato-Oncology unit in Spain. It included questions about epidemiology, management, psycho-social coverage, specific facilities, and follow up of these patients. A total of 40 institutions out of 41 responded to the survey (overall response rate 98%). Fifty-six percent of the institutions had patients over 14, but only 36% of the institutions treated patients up to 18 years old. Only 25.6% of the units have more than 40 new pediatric cases every year. The percentage of patients between 14 and 18 years of age is below 10% in most of the units (77%). In 30.8% and 48.7% of the institutions, pediatric hemato-oncologists treat adolescents with hematological and solid tumors, respectively. The rest of the patients are seen by adult oncologists. There is only one institution that has a physician specifically dedicated to adolescent patients, and only two units have a "teenager's room". Only 2 units have a psychologist specifically trained to treat adolescents with cancer. The survey shows that most adolescents with cancer in Spain between 14 and 18 years of age are treated by adult oncologists. Most pediatric institutions still do not have specific facilities and psychosocial support for adolescents. The SEHOP is working hard in order to improve the quality of cancer care, and the quality of survival of this population.


Subject(s)
Neoplasms/epidemiology , Adolescent , Health Care Surveys , Hematology , Hospital Units , Humans , Medical Oncology , Pediatrics , Spain , Surveys and Questionnaires
8.
Virus Genes ; 23(1): 105-18, 2001.
Article in English | MEDLINE | ID: mdl-11556396

ABSTRACT

The complete sequence (28580 nt) of the PUR46-MAD clone of the Purdue cluster of transmissible gastroenteritis coronavirus (TGEV) has been determined and compared with members of this cluster and other coronaviruses. The computing distances among their S gene sequences resulted in the grouping of these coronaviruses into four clusters, one of them exclusively formed by the Purdue viruses. Three new potential sequence motifs with homology to the alpha-subunit of the polymerase-associated nucleocapsid phosphoprotein of rinderpest virus, the Bowman-Birk type of proteinase inhibitors, and the metallothionein superfamily of cysteine rich chelating proteins have been identified. Comparison of the TGEV polymerase sequence with that of other RNA viruses revealed high sequence homology with the A-E domains of the palm subdomain of nucleic acid polymerases.


Subject(s)
Evolution, Molecular , Genome, Viral , Transmissible gastroenteritis virus/genetics , Amino Acid Sequence , Animals , Molecular Sequence Data , Open Reading Frames , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Swine , Transmissible gastroenteritis virus/classification , Transmissible gastroenteritis virus/isolation & purification
9.
J Biotechnol ; 88(3): 183-204, 2001 Jul 12.
Article in English | MEDLINE | ID: mdl-11434966

ABSTRACT

Both helper dependent expression systems, based on two components, and single genomes constructed by targeted recombination, or by using infectious cDNA clones, have been developed. The sequences that regulate transcription have been characterized mainly using helper dependent expression systems and it will now be possible to validate them using single genomes. The genome of coronaviruses has been engineered by modification of the infectious cDNA leading to an efficient (>20 microg ml(-1)) and stable (>20 passages) expression of the foreign gene. The possibility of engineering the tissue and species tropism to target expression to different organs and animal species, including humans, increases the potential of coronaviruses as vectors. Thus, coronaviruses are promising virus vectors for vaccine development and, possibly, for gene therapy.


Subject(s)
Coronavirus/genetics , Genetic Vectors/genetics , Coronavirus/pathogenicity , Gene Expression Regulation, Viral , Genetic Therapy/methods , Genome, Viral , Humans , Transcription, Genetic , Tropism , Vaccines
10.
J Virol ; 75(15): 7018-29, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11435582

ABSTRACT

A characterization of the A45R gene from vaccinia virus (VV) strain Western Reserve is presented. The open reading frame is predicted to encode a 125-amino-acid protein (M(r), of 13,600) with 39% amino acid identity to copper-zinc superoxide dismutase (Cu-Zn SOD). Sequencing of the A45R gene from other orthopoxviruses, here and by others, showed that the protein is highly conserved in all viruses sequenced, including 16 strains of VV, 2 strains of cowpox virus, camelpox virus, and 4 strains of variola virus. In all cases the protein lacks key residues involved in metal ion binding that are important for the catalytic activity. The A45R protein was expressed in Escherichia coli, purified, and tested for SOD activity, but neither enzymatic nor inhibitory SOD activity was detected. Additionally, no virus-encoded SOD activity was detected in infected cells or purified virions. A monoclonal antibody raised against the A45R protein expressed in E. coli identified the A45R gene product as a 13.5-kDa protein that is expressed late during VV infection. Confocal microscopy of VV-infected cells indicated that the A45R protein accumulated predominantly in cytoplasmic viral factories. Electron microscopy and biochemical analyses showed that the A45R protein is incorporated into the virion core. A deletion mutant lacking the majority of the A45R gene and a revertant virus in which the deleted gene was restored were constructed and characterized. The growth properties of the deletion mutant virus were indistinguishable from those of wild-type and revertant viruses in all cell lines tested, including macrophages. Additionally, the virulence and pathogenicity of the three viruses were also comparable in murine and rabbit models of infection. A45R is unusual in being the first VV core protein described that affects neither virus replication nor virulence.


Subject(s)
Superoxide Dismutase/metabolism , Vaccinia virus/enzymology , Viral Proteins/metabolism , Virus Replication , Animals , Base Sequence , Cell Line , Conserved Sequence , DNA, Viral , Escherichia coli , Gene Expression , Genes, Viral , Genome, Viral , Haplorhini , HeLa Cells , Humans , Molecular Sequence Data , Orthopoxvirus/genetics , Peptides/genetics , Rabbits , Subcellular Fractions , Superoxide Dismutase/genetics , Vaccinia virus/growth & development , Vaccinia virus/pathogenicity , Vaccinia virus/physiology , Viral Core Proteins/genetics , Viral Core Proteins/metabolism , Viral Proteins/genetics , Virion , Virulence
14.
Proc Natl Acad Sci U S A ; 97(10): 5516-21, 2000 May 09.
Article in English | MEDLINE | ID: mdl-10805807

ABSTRACT

The construction of cDNA clones encoding large-size RNA molecules of biological interest, like coronavirus genomes, which are among the largest mature RNA molecules known to biology, has been hampered by the instability of those cDNAs in bacteria. Herein, we show that the application of two strategies, cloning of the cDNAs into a bacterial artificial chromosome and nuclear expression of RNAs that are typically produced within the cytoplasm, is useful for the engineering of large RNA molecules. A cDNA encoding an infectious coronavirus RNA genome has been cloned as a bacterial artificial chromosome. The rescued coronavirus conserved all of the genetic markers introduced throughout the sequence and showed a standard mRNA pattern and the antigenic characteristics expected for the synthetic virus. The cDNA was transcribed within the nucleus, and the RNA translocated to the cytoplasm. Interestingly, the recovered virus had essentially the same sequence as the original one, and no splicing was observed. The cDNA was derived from an attenuated isolate that replicates exclusively in the respiratory tract of swine. During the engineering of the infectious cDNA, the spike gene of the virus was replaced by the spike gene of an enteric isolate. The synthetic virus replicated abundantly in the enteric tract and was fully virulent, demonstrating that the tropism and virulence of the recovered coronavirus can be modified. This demonstration opens up the possibility of employing this infectious cDNA as a vector for vaccine development in human, porcine, canine, and feline species susceptible to group 1 coronaviruses.


Subject(s)
Coronavirus/immunology , Escherichia coli/genetics , Genetic Engineering/methods , Genome, Viral , RNA, Viral/genetics , Transmissible gastroenteritis virus/genetics , Animals , Cat Diseases/immunology , Cats , Cell Line , Cloning, Molecular , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , DNA, Complementary , Dog Diseases/immunology , Dogs , Humans , Male , Molecular Sequence Data , Swine , Testis , Viral Vaccines
15.
Vet Immunol Immunopathol ; 73(1): 73-81, 2000 Jan 31.
Article in English | MEDLINE | ID: mdl-10678400

ABSTRACT

CD46 is a major transmembrane glycoprotein that belongs to the regulator of complement activation (RCA) family. Recently, mAbs to human CD46 were shown to suppress IL-12 production. Here, we describe that mAbs against different porcine CD46 epitopes induced a marked adhesion of normal lymphocytes. Addition of low amounts of antibody to freshly isolated lymphocytes or thymocytes resulted in the clustering of the cells. Cross-linking of CD46 molecules seems essential since Fab fragments failed to induce aggregation. This aggregation was dependent on active cell metabolism and on the presence of divalent cations and required a functional cytoskeleton. It was not inhibited by antibodies to CD18, CD29, CD2, CD11a and CD11b. Staurosporine, an inhibitor of protein kinases, partially blocked the aggregation. This finding is indicative of a role of protein kinases in the transduction of the signal generated by CD46 engagement.


Subject(s)
Antibodies, Monoclonal/immunology , Antigens, CD/physiology , Lymphocytes/physiology , Membrane Glycoproteins/physiology , Swine/immunology , Animals , Cell Aggregation , Membrane Cofactor Protein , Mice , Mice, Inbred BALB C
16.
Virology ; 266(2): 340-51, 2000 Jan 20.
Article in English | MEDLINE | ID: mdl-10639320

ABSTRACT

The open reading frame EP153R, located within the EcoRI E' fragment of the African swine fever (ASF) virus genome, is predicted to encode a membrane protein of 153 amino acids that presents significant homology to the N-terminal region of several CD44 molecules. EP153R contains multiple putative sites for N-glycosylation, phosphorylation, and myristoylation, a central transmembrane region, a C-type animal lectin-like domain, and a cell attachment sequence. Transcription of EP153R takes place at both early and late times during the virus infection. The disruption of the gene, achieved by insertion of the marker gene LacZ within EP153R, did not change either the in vitro virus growth rate or the virus-sensitive/resistant condition of up to 17 established cell lines, but abrogated the hemadsorption phenomenon induced in ASF virus-infected cells. As the sequence and expression of the ASF virus protein pEP402R, a CD2 homolog responsible for the adhesion of erythrocytes to susceptible cells, was unaffected in cultures infected with the EP153R deletion mutant, we conclude that the gene EP153R is needed to induce and/or maintain the interaction between the viral CD2 homolog and its corresponding cell receptor.


Subject(s)
African Swine Fever Virus/genetics , African Swine Fever Virus/pathogenicity , Genes, Viral , Viral Proteins/genetics , Viral Proteins/physiology , Amino Acid Sequence , Animals , Base Sequence , Cell Adhesion , Cell Line , DNA, Viral/genetics , Gene Deletion , Humans , Hyaluronan Receptors/genetics , Lectins/genetics , Molecular Sequence Data , Open Reading Frames , Sequence Homology, Amino Acid
17.
Immunology ; 96(4): 663-70, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10233756

ABSTRACT

Pig membrane cofactor protein (MCP; CD46) is a 50 000-60 000 MW glycoprotein that is expressed on a wide variety of cells, including erythrocytes. Pig MCP has cofactor activity for factor I-mediated cleavage of C3b and is an efficient regulator of the classical and alternative pathway of human and pig complement. A panel of 10 monoclonal antibodies (mAbs) was collected from two different laboratories; all of these mAbs were raised against pig leucocytes and all recognized the same complex banding pattern on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of erythrocyte membranes. All were shown to be reactive with pig MCP and were divided into four groups of mutually competitive antibodies based on competition studies for membrane-bound MCP and for soluble MCP, the latter by surface plasmon resonance (SPR) analysis. The antigenic properties of membrane-bound and soluble MCP were similar, although some interesting differences were revealed. None of the 10 mAbs were cross-reactive with human MCP and only one showed cross-reactivity with leucocytes from a panel of large mammals - a weak cross-reactivity with a subset of dog leucocytes. All antibodies in one of the epitope groups and some in a second epitope group were able to block the functional activity of pig MCP, as measured by inhibition of MCP-catalysed C3 degradation by factor I.


Subject(s)
Antibodies, Monoclonal/immunology , Antigens, CD/immunology , Complement Inactivator Proteins/immunology , Epitope Mapping , Membrane Glycoproteins/immunology , Swine/immunology , Animals , Antibody Specificity , Binding, Competitive , Cross Reactions , Dogs , Electrophoresis, Polyacrylamide Gel , Humans , Leukocytes/immunology , Membrane Cofactor Protein , Species Specificity , Surface Plasmon Resonance
18.
J Virol ; 72(4): 3185-95, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9580160

ABSTRACT

A method to study the function of individual African swine fever virus (ASFV) gene products utilizing the Escherichia coli lac repressor-operator system has been developed. Recombinant viruses containing both the lacI gene encoding the lac repressor and a strong virus late promoter modified by the insertion of one or two copies of the lac operator sequence at various positions were constructed. The ability of each modified promoter to regulate expression of the firefly luciferase gene was assayed in the presence and in the absence of the inducer isopropyl beta-D-thiogalactoside (IPTG). Induction and repression of gene activity were dependent on the position(s) of the operator(s) with respect to the promoter and on the number of operators inserted. The ability of this system to regulate the expression of ASFV genes was analyzed by constructing a recombinant virus inducibly expressing the major capsid protein p72. Electron microscopy analysis revealed that under nonpermissive conditions, electron-dense membrane-like structures accumulated in the viral factories and capsid formation was inhibited. Induction of p72 expression allowed the progressive building of the capsid on these structures, leading to assembly of ASFV particles. The results of this report demonstrate that the transferred inducible expression system is a powerful tool for analyzing the function of ASFV genes.


Subject(s)
African Swine Fever Virus/genetics , Capsid Proteins , Capsid/genetics , Escherichia coli Proteins , Gene Expression Regulation, Viral , African Swine Fever Virus/ultrastructure , Animals , Bacterial Proteins/genetics , Capsid/metabolism , Chlorocebus aethiops , Cloning, Molecular , Genetic Vectors , Isopropyl Thiogalactoside/pharmacology , Lac Repressors , Morphogenesis , Operator Regions, Genetic , Plasmids , Promoter Regions, Genetic , Rabbits , Rats , Recombinant Fusion Proteins/genetics , Repressor Proteins/genetics , Vero Cells , Virion/metabolism
19.
J Virol ; 71(8): 5799-804, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9223468

ABSTRACT

We have identified an open reading frame (ORF), CP530R, within the EcoRI C' fragment of the African swine fever virus (ASFV) genome that encodes a polyprotein of 62 kDa (pp62). Antisera raised against different regions of ORF CP530R recognized a polypeptide of 62 kDa in ASFV-infected cells during the late phase of virus replication, after the onset of viral DNA synthesis. Pulse-chase experiments showed that polyprotein pp62 is posttranslationally processed to give rise to two proteins of 35 kDa (p35) and 15 kDa (p15). This proteolytic processing was found to take place at the consensus sequence Gly-Gly-X through an ordered cascade of proteolytic cleavages like that which also occurs with ASFV polyprotein pp220 (C. Simón-Mateo, G. Andrés, and E. Viñuela, EMBO J. 12:2977-2987, 1993). Immunofluorescence studies showed that polyprotein pp62 is localized in the viral factories. In addition, immunoprecipitation analysis of purified virus particles showed that mature products p35 and p15 are major structural proteins. According to these results, polyprotein processing represents an essential strategy for the maturation of ASFV structural proteins.


Subject(s)
African Swine Fever Virus/metabolism , Viral Structural Proteins/metabolism , African Swine Fever Virus/genetics , Amino Acid Sequence , Animals , Base Sequence , Chlorocebus aethiops , Molecular Sequence Data , Molecular Weight , Open Reading Frames , Vero Cells , Viral Structural Proteins/analysis
20.
Biochim Biophys Acta ; 1361(1): 92-102, 1997 Jul 10.
Article in English | MEDLINE | ID: mdl-9247093

ABSTRACT

The Leishmania cell surface virulence factor gp63 is a protease family that plays an important role in the survival of the parasite protozoon into the host macrophages. We have cloned and characterised the gp63 gene from L. infantum. The sequence analysis of the gene indicates the existence of a high degree of conservation with the other old world species L. major and L. donovani. The similarity is lower with new world species with the exception of L. chagasi which shows a strikingly high percentage of identity (99-100%). In L. infantum the gp63 gene expresses two polypeptides of 58 and 60 kDa, respectively, which show a similar proteolytic activity. The 60 kDa polypeptide is expressed during the whole life cycle of the promastigote form of the parasite with a moderate increase at the stationary phase of growth while the 58 kDa product, although slightly present in the logarithmic phase, notable increases its expression during the highly infectious stationary phase. RNA analysis showed that the presence in L. chagasi of these two polypeptides correlates with two RNA molecules and with the degree of parasite infectivity, whereas in the case of L. infantum a single 3 kb messenger RNA is detected through the whole promastigote life cycle. Our data indicate that in L. infantum, the differences in gene expression of the gp63 protease family according to parasite phase of growth seem to be due to a differential pattern of glycosilation of the polypeptides which correlates with the different infective forms of the promastigote form of the parasite.


Subject(s)
Leishmania/genetics , Metalloendopeptidases/genetics , Amino Acid Sequence , Animals , Base Sequence , Blotting, Northern , Cloning, Molecular , Gene Expression Regulation , Glycosylation , Leishmania/physiology , Metalloendopeptidases/metabolism , Molecular Sequence Data , Protein Processing, Post-Translational , Virulence
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