RESUMEN
The purpose of this study was to compare the effects of the radial forearm free flap (RFFF) and groin soft tissue free flap (GSFF) on the quality of life (QoL) of patients undergoing reconstructive surgery after resection for oral cancer. A retrospective analysis of 48 patients was performed. The Vancouver Scar Scale (VSS), University of Washington Quality of Life (UW-QOL) questionnaire, and 14-item Oral Health Impact Profile (OHIP-14) questionnaire were used to evaluate the donor site scars and QoL of the patients. The postoperative hospital stay was significantly longer in the RFFF group than in the GSFF group (P = 0.001). Furthermore, the total VSS score (P = 0.011), VSS score for pigmentation (P < 0.001), and OHIP-14 scores for psychological discomfort (P = 0.026) and social disability (P = 0.044) were all significantly higher in the RFFF group than in the GSFF group, while the UW-QOL scores for appearance (P = 0.037) and mood (P = 0.036) were significantly lower in the RFFF group than in the GSFF group. Compared with the RFFF, the GSFF scar is more concealed, with better aesthetics at the donor site, and this flap can result in improved postoperative QoL for patients with oral cancer.
Asunto(s)
Colgajos Tisulares Libres , Neoplasias de la Boca , Procedimientos de Cirugía Plástica , Cicatriz/cirugía , Estética Dental , Ingle/cirugía , Humanos , Neoplasias de la Boca/cirugía , Calidad de Vida , Estudios RetrospectivosRESUMEN
Trichinellosis is a public health problem and is regarded as an emergent/re-emergent disease in various countries. The cDNA encoding a cystatin-like protein (Ts-cystatin) was identified by immunoscreening intestinal muscle larvae cDNA libraries with serum from pigs experimentally infected with 20,000 Trichinella spiralis muscle larvae. To study its impact on host immunity, we chose a eukaryotic expression system based on several comparisons of immunogenicity between the two Salmonella typhimurium administration schemes, which indicated that the eukaryotic expression system was superior. Humoral IgG and mucosal IgA were measured to determine the antibody response. To explore whether Th1 and Th2 responses were responsible for the induced protection, Th1- and Th2-specific cellular transcription factors and the cytokine profile were examined. Changes in the T lymphocyte and macrophage populations were detected by flow cytometry. Lastly, parasitological examination was examined. The results showed that Ts-cystatin induced a Th1/Th2-mixed type of immune response and decreased STAT6 transcription. The intestinal adult recovery increased by 10.9% in the Ts-cystatin group, the Ts-cystatin group fecundity rate was decreased by 91%. Furthermore, the number of muscle larvae did not change compared with the control group. In conclusion, our results suggest that Ts-cystatin plays an important role in Trichinella resistance to rapid expulsion by the host and is worth further study.
Asunto(s)
Cistatinas/inmunología , Trichinella spiralis/inmunología , Triquinelosis/prevención & control , Vacunas Atenuadas/administración & dosificación , Vacunas Sintéticas/administración & dosificación , Administración Oral , Animales , Cistatinas/administración & dosificación , Cistatinas/genética , Citocinas/análisis , Femenino , Expresión Génica , Vectores Genéticos , Inmunoglobulina A Secretora/análisis , Inmunoglobulina G/sangre , Mucosa Intestinal/inmunología , Macrófagos/inmunología , Ratones , Ratones Endogámicos BALB C , Distribución Aleatoria , Ratas , Ratas Wistar , Salmonella , Organismos Libres de Patógenos Específicos , Bazo/inmunología , Linfocitos T/inmunología , Transcripción Genética , Trichinella spiralis/genética , Vacunas Atenuadas/genética , Vacunas Atenuadas/inmunología , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunologíaRESUMEN
Both host and parasite factors contribute to disease severity of malaria infection; however, the molecular mechanisms responsible for the disease and the host-parasite interactions involved remain largely unresolved. To investigate the effects of parasite factors on host immune responses and pathogenesis, we measured levels of plasma cytokines/chemokines (CCs) and growth rates in mice infected with two Plasmodium yoelii strains having different virulence phenotypes and in progeny from a genetic cross of the two parasites. Quantitative trait loci (QTL) analysis linked levels of many CCs, particularly IL-1ß, IP-10, IFN-γ, MCP-1 and MIG, and early parasite growth rate to loci on multiple parasite chromosomes, including chromosomes 7, 9, 10, 12 and 13. Comparison of the genome sequences spanning the mapped loci revealed various candidate genes. The loci on chromosomes 7 and 13 had significant (P<0.005) additive effects on IL-1ß, IL-5 and IP-10 responses, and the chromosome 9 and 12 loci had significant (P=0.017) interaction. Infection of knockout mice showed critical roles of MCP-1 and IL-10 in parasitemia control and host mortality. These results provide important information for a better understanding of malaria pathogenesis and can be used to examine the role of these factors in human malaria infection.
Asunto(s)
Citocinas/metabolismo , Sitios Genéticos , Malaria/inmunología , Malaria/metabolismo , Plasmodium/genética , Plasmodium/inmunología , Animales , Quimiocina CCL2/sangre , Quimiocina CCL2/metabolismo , Quimiocinas/sangre , Quimiocinas/metabolismo , Cruzamientos Genéticos , Citocinas/sangre , Modelos Animales de Enfermedad , Epistasis Genética , Femenino , Genes Protozoarios , Genoma de Protozoos , Interacciones Huésped-Patógeno , Malaria/sangre , Malaria/genética , Malaria/mortalidad , Ratones , Ratones Noqueados , Plasmodium yoelii/genética , Plasmodium yoelii/inmunología , Polimorfismo Genético , Sitios de Carácter CuantitativoRESUMEN
Chloroquine (CQ) is the most successful antimalarial drug ever discovered. Unfortunately, parasites resistant to the drug eventually emerged after its large scale use and are now widespread. Although great progress in our understanding of the mechanisms of CQ action and CQ resistance (CQR) has been achieved over the past two decades, including the identification of the molecules responsible for CQR (e.g., Plasmodium falciparum chloroquine resistant transporter, PfCRT) many questions remain unanswered. Here we highlight recent advances in our understanding of the genetics and molecular mechanisms of CQR, with particular emphasis on the role of genes such as pfcrt and pfmdr1 in the resistance to CQ and other drugs. New drug development and applications will undoubtedly benefit from a better understanding of CQR, eventually leading to more effective malaria control measures.
Asunto(s)
Antimaláricos/farmacología , Cloroquina/farmacología , Resistencia a Medicamentos/genética , Proteínas de Transporte de Membrana/fisiología , Plasmodium falciparum/genética , Proteínas Protozoarias/fisiología , Animales , Plasmodium falciparum/efectos de los fármacosRESUMEN
Drug resistance is one of the major factors contributing to the resurgence of malaria, especially resistance to the most affordable drugs such as chloroquine and Fansidar, a combination drug of pyrimethamine and sulfadoxine. Understanding the mechanisms of such resistance and developing new treatments, including new drugs, are urgently needed. Great progress has been made recently in studying the mechanisms of drug action and drug resistance in malaria parasites, particularly in Plasmodium falciparum. These efforts are highlighted by the demonstration of mutations in the parasite dihydrofolate reductase and dihydropteroate synthase genes conferring resistance to pyrimethamine and sulfadoxine, respectively, and by the recent discovery of mutations in the gene coding for a putative transporter, PfCRT, conferring resistance to chloroquine. Mutations in a homologue of a human multiple-drug-resistant gene, pfmdr1, have also been shown to be associated with responses to multiple drugs. However, except in the case of resistance to antifolate drugs, the mechanisms of action and resistance to most drugs currently in use are essentially unknown or are being debated. Additionally, novel mechanisms of resistance exist in different malaria parasites, complicating the process of developing new drugs and treatment strategies. Here we summarise the progress made in drug resistance research in malaria parasites over the past 20 years, emphasising the most recent developments in the genetics of drug resistance.
Asunto(s)
Antimaláricos/farmacología , Resistencia a Medicamentos/genética , Malaria/parasitología , Plasmodium falciparum/efectos de los fármacos , Plasmodium vivax/efectos de los fármacos , Animales , Antimaláricos/metabolismo , Antimaláricos/uso terapéutico , Cloroquina/farmacología , Dihidropteroato Sintasa/genética , Resistencia a Múltiples Medicamentos , Humanos , Desequilibrio de Ligamiento , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Malaria Vivax/tratamiento farmacológico , Malaria Vivax/epidemiología , Malaria Vivax/parasitología , Mefloquina/farmacología , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana , Mutación , Fenantrenos/farmacología , Plasmodium falciparum/genética , Plasmodium vivax/genética , Proteínas Protozoarias , Pirimetamina/farmacología , Sulfadoxina/farmacología , Tetrahidrofolato Deshidrogenasa/genéticaRESUMEN
Autochthonous Plasmodium falciparum malaria (PFM) in Central Europe has been reported repeatedly, transmission of the parasite being attributed to blood transfusion or imported P. falciparum-infected vectors. We report two cases of PFM in German children without travel history to malaria-endemic areas. Both infections occurred during a stay in a hospital where a child from Angola with chronic P. falciparum infection was hospitalized at the time. Known routes of transmission, such as imported mosquitoes or blood transfusion, were very unlikely or could be excluded, whereas evidence was obtained for transmission by the indigenous mosquito species Anopheles plumbeus.
Asunto(s)
Anopheles/parasitología , Malaria Falciparum/parasitología , Malaria Falciparum/transmisión , Plasmodium falciparum/aislamiento & purificación , Adulto , Animales , Niño , Preescolar , ADN Protozoario/análisis , Femenino , Alemania , Humanos , Insectos Vectores/parasitología , Plasmodium falciparum/clasificación , Plasmodium falciparum/genética , Reacción en Cadena de la PolimerasaRESUMEN
BACKGROUND: Chloroquine-resistant Plasmodium falciparum malaria is a major health problem, particularly in sub-Saharan Africa. Chloroquine resistance has been associated in vitro with point mutations in two genes, pfcrt and pfmdr 1, which encode the P. falciparum digestive-vacuole transmembrane proteins PfCRT and Pgh1, respectively. METHODS: To assess the value of these mutations as markers for clinical chloroquine resistance, we measured the association between the mutations and the response to chloroquine treatment in patients with uncomplicated falciparum malaria in Mali. The frequencies of the mutations in patients before and after treatment were compared for evidence of selection of resistance factors as a result of exposure to chloroquine. RESULTS: The pfcrt mutation resulting in the substitution of threonine (T76) for lysine at position 76 was present in all 60 samples from patients with chloroquine-resistant infections (those that persisted or recurred after treatment), as compared with a base-line prevalence of 41 percent in samples obtained before treatment from 116 randomly selected patients (P<0.001), indicating absolute selection for this mutation. The pfmdr 1 mutation resulting in the substitution of tyrosine for asparagine at position 86 was also selected for, since it was present in 48 of 56 post-treatment samples from patients with chloroquine-resistant infections (86 percent), as compared with a base-line prevalence of 50 percent in 115 samples obtained before treatment (P<0.001). The presence of pfcrt T76 was more strongly associated with the development of chloroquine resistance (odds ratio, 18.8; 95 percent confidence interval, 6.5 to 58.3) than was the presence of pfmdr 1 Y86 (odds ratio, 3.2; 95 percent confidence interval, 1.5 to 6.8) or the presence of both mutations (odds ratio, 9.8; 95 percent confidence interval, 4.4 to 22.1). CONCLUSIONS: This study shows an association between the pfcrt T76 mutation in P. falciparum and the development of chloroquine resistance during the treatment of malaria. This mutation can be used as a marker in surveillance for chloroquine-resistant falciparum malaria.
Asunto(s)
Cloroquina/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Plasmodium falciparum/genética , Mutación Puntual , Adulto , Factores de Edad , Animales , Niño , Cloroquina/farmacología , Análisis Mutacional de ADN , Resistencia a Medicamentos/genética , Marcadores Genéticos , Humanos , Modelos Logísticos , Malaria Falciparum/parasitología , Plasmodium falciparum/efectos de los fármacos , Valor Predictivo de las Pruebas , Prevalencia , Selección Genética , Resultado del TratamientoRESUMEN
The determinant of verapamil-reversible chloroquine resistance (CQR) in a Plasmodium falciparum genetic cross maps to a 36 kb segment of chromosome 7. This segment harbors a 13-exon gene, pfcrt, having point mutations that associate completely with CQR in parasite lines from Asia, Africa, and South America. These data, transfection results, and selection of a CQR line harboring a novel K761 mutation point to a central role for the PfCRT protein in CQR. This transmembrane protein localizes to the parasite digestive vacuole (DV), the site of CQ action, where increased compartment acidification associates with PfCRT point mutations. Mutations in PfCRT may result in altered chloroquine flux or reduced drug binding to hematin through an effect on DV pH.
Asunto(s)
Cloroquina/farmacología , Proteínas de la Membrana/metabolismo , Plasmodium falciparum/genética , Proteínas Protozoarias/genética , Vacuolas/fisiología , Secuencia de Aminoácidos , Animales , Animales Modificados Genéticamente , Sistema Digestivo/metabolismo , Resistencia a Medicamentos , Exones , Humanos , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Plasmodium falciparum/efectos de los fármacos , Reacción en Cadena de la Polimerasa , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Tetrahidrofolato Deshidrogenasa/genética , Transfección , Verapamilo/farmacologíaRESUMEN
Microsatellite loci are generally assumed to evolve via a stepwise mutational process and a battery of statistical techniques has been developed in recent years based on this or related mutation models. It is therefore important to investigate the appropriateness of these models in a wide variety of taxa. We used two approaches to examine mutation patterns in the malaria parasite Plasmodium falciparum: (i) we examined sequence variation at 12 tri-nucleotide repeat loci; and (ii) we analysed patterns of repeat structure and heterozygosity at 114 loci using data from 12 laboratory parasite lines. The sequencing study revealed complex patterns of mutation in five of the 12 loci studied. Alleles at two loci contain indels of 24 bp and 57 bp in flanking regions, while in the other three loci, blocks of imperfect microsatellites appear to be duplicated or inserted; these loci essentially consist of minisatellite repeats, with each repeat unit containing four to eight microsatellites. The survey of heterozygosity revealed a positive relationship between repeat number and microsatellite variability for both di- and trinucleotides, indicating a higher mutation rate in loci with longer repeat arrays. Comparisons of levels of variation in different repeat types indicate that the mutation rate of dinucleotide-bearing loci is 1.6-2.1 times faster than trinucleotides, consistent with the lower mean number of repeats in trinucleotide-bearing loci. However, despite the evidence that microsatellite arrays themselves are evolving in a manner consistent with stepwise mutation model in P. falciparum, the high frequency of complex mutations precludes the use of analytical tools based on this mutation model for many microsatellite-bearing loci in this protozoan. The results call into question the generality of models based on stepwise mutation for analysing microsatellite data, but also demonstrate the ease with which loci that violate model assumptions can be detected using minimal sequencing effort.
Asunto(s)
Repeticiones de Microsatélite , Mutación , Plasmodium falciparum/genética , Animales , Secuencia de Bases , Evolución Molecular , Heterocigoto , Datos de Secuencia Molecular , Análisis de Secuencia de ADNRESUMEN
Whole-genome methods are changing the scope of biological questions that can be addressed in malaria research. In the rich context provided by Plasmodium falciparum genome sequencing, genetic mapping is a powerful tool for identifying genes involved in parasite development, invasion, transmission and drug resistance. The recent development of a high-resolution P. falciparum linkage map consisting of hundreds of microsatellite markers will facilitate an integrated genomic approach to understanding the relationship between genetic variations and biological phenotypes. Here, Michael Ferdig and Xin-zhuan Su provide an overview for applying microsatellite markers and genetic maps to gene mapping, parasite typing and studies of parasite population changes.
Asunto(s)
Mapeo Cromosómico , Malaria Falciparum/parasitología , Repeticiones de Microsatélite/genética , Plasmodium falciparum/genética , Animales , Ligamiento Genético , Variación Genética/genética , Humanos , Plasmodium falciparum/clasificaciónRESUMEN
The complex human and parasite determinants that influence disease severity in Plasmodium falciparum malaria reflect thousands of years of selective pressure. Emerging genetic and genomic resources offer the prospect of unraveling interactions of these determinants.
Asunto(s)
Interacciones Huésped-Parásitos/genética , Malaria Falciparum/genética , Plasmodium falciparum/genética , Animales , Humanos , Malaria Falciparum/fisiopatología , Polimorfismo Genético , Selección GenéticaRESUMEN
Multiple, selectively neutral genetic markers are the most appropriate tools for analysis of parasite population structure and epidemiology, but yet existing methods for characterization of malaria field samples utilize a limited number of antigen encoding genes, which appear to be under strong selection. We describe protocols for characterization of 12 microsatellite markers from finger-prick blood samples infected with Plasmodium falciparum. A two-step, heminested strategy was used to amplify all loci, and products were visualized by fluorescent end-labelling of internal primers. This procedure allows amplification from low levels of template, while eliminating the problem of spurious products due to primer carry over from the primary round of PCR. The loci can be conveniently multiplexed, while accurate sizing and quantification of PCR products can be automated using the GENOTYPER software. The primers do not amplify co-infecting malaria species such as P. vivax and P. malariae. To demonstrate the utility of these markers, we characterized 57 infected finger-prick blood samples from the village of Mebat in Papua New Guinea for all 12 loci, and all samples were genotyped a second time to measure reproducibility. Numbers of alleles per locus range from 4 to 10 in this population, while heterozygosities range from 0.21 to 0.87. Reproducibility (measured as concordance between predominant alleles detected in replicate samples) ranged from 92 to 98% for the 12 loci. The composition of PCR products from infections containing multiple malaria clones could also be defined using strict criteria and scored in a highly repeatable manner.
Asunto(s)
ADN Protozoario/genética , Malaria Falciparum/sangre , Repeticiones de Microsatélite , Plasmodium falciparum/genética , Reacción en Cadena de la Polimerasa/métodos , Alelos , Animales , Cartilla de ADN , Dedos , Marcadores Genéticos , Variación Genética , Heterocigoto , Humanos , Malaria Falciparum/epidemiología , Papúa Nueva Guinea/epidemiología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , Especificidad de la Especie , Manejo de EspecímenesRESUMEN
Genome analysis of the Plasmodium falciparum malaria parasite already is identifying genes relevant to therapeutic- and vaccine-related research. The genetic blueprint of P. falciparum will ultimately need to be understood at multiple levels of an integrated system and will provide a detailed account of the life processes of the parasite and of the devastating disease it causes.
Asunto(s)
Genoma de Protozoos , Plasmodium falciparum/genética , Animales , Humanos , Malaria Falciparum/parasitología , Malaria Falciparum/prevención & controlAsunto(s)
Dermatoglifia del ADN/métodos , ADN Protozoario/análisis , ADN Satélite/análisis , Familia de Multigenes , Plasmodium falciparum/genética , Animales , Secuencia de Bases , Cartilla de ADN/química , ADN Protozoario/química , ADN Satélite/química , Genes Protozoarios , Datos de Secuencia Molecular , Familia de Multigenes/genética , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Factores de TiempoRESUMEN
The Plasmodium falciparum Genome Project is a collaborative effort by many laboratories that will provide detailed molecular information about the parasite, which may be used for developing practical control measures. Initial goals are to prepare an electronically indexed clone bank containing partially sequenced clones representing up to 80% of the parasite's genes and to prepare an ordered set of overlapping clones spanning each of the parasite's 14 chromosomes. Currently, clones of genomic DNA, prepared as yeast artificial chromosomes, are arranged into contigs covering approximately 70% of the genome of parasite clone 3D7, gene sequence tags are available from more than contigs covering approximately 70% of the genome of parasite clone 3D7, gene sequence tags are available from more than 20% of the parasite's genes, and approximately 5% of the parasite's genes are tentatively identified from similarity searches of entries in the international sequence databases. A total of > 0.5 Mb of P. falciparum sequence tag data is available. The gene sequence tags are presently being used to complete YAC contig assembly and localize the cloned genes to positions on the physical map in preparation for sequencing the genome. Routes of access to project information and services are described.
Asunto(s)
Genoma de Protozoos , Plasmodium falciparum/genética , Animales , Núcleo Celular/genética , Mapeo Cromosómico , ADN Complementario/genética , Expresión Génica , Genes Protozoarios , Datos de Secuencia Molecular , Organizaciones , Análisis de Secuencia de ADNRESUMEN
A total of 507 simple sequence repeats (SSRs or "microsatellites") were identified from Plasmodium falciparum sequences in GenBank and from inserts in a genomic DNA library. Oligonucleotide primers from sequences that flank 224 of these SSRs were synthesized and used in PCR assays to test for simple sequence length polymorphisms (SSLPs). Of the 224 SSRs, 188 showed SSLPs among 12 different P. falciparum lines; 116 of these SSLPs were assigned to chromosome linkage groups by physical mapping and by comparing their inheritance patterns against those of restriction fragment length polymorphism markers in a genetic cross (HB3xDd2). The predominant SSLPs in P. falciparum were found to contain [TA]n, [T]n, and [TAA]n, a feature that is reminiscent of plant genomes and is consistent with the proposed algal-like origin of malaria parasites. Since such SSLPs are abundant and readily isolated, they are a powerful resource for genetic analysis of P. falciparum.