Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 199
Filtrar
Más filtros

Intervalo de año de publicación
1.
BMC Med ; 17(1): 14, 2019 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-30665398

RESUMEN

BACKGROUND: Substantial global progress in the control of malaria in recent years has led to increased commitment to its potential elimination. Whether this is possible in high transmission areas of sub-Saharan Africa remains unclear. Zanzibar represents a unique case study of such attempt, where modern tools and strategies for malaria treatment and vector control have been deployed since 2003. METHODS: We have studied temporal trends of comprehensive malariometric indices in two districts with over 100,000 inhabitants each. The analyses included triangulation of data from annual community-based cross-sectional surveys, health management information systems, vital registry and entomological sentinel surveys. RESULTS: The interventions, with sustained high-community uptake, were temporally associated with a major malaria decline, most pronounced between 2004 and 2007 and followed by a sustained state of low transmission. In 2015, the Plasmodium falciparum community prevalence of 0.43% (95% CI 0.23-0.73) by microscopy or rapid diagnostic test represented 96% reduction compared with that in 2003. The P. falciparum and P. malariae prevalence by PCR was 1.8% (95% CI 1.3-2.3), and the annual P. falciparum incidence was estimated to 8 infections including 2.8 clinical episodes per 1000 inhabitants. The total parasite load decreased over 1000-fold (99.9%) between 2003 and 2015. The incidence of symptomatic malaria at health facilities decreased by 94% with a trend towards relatively higher incidence in age groups > 5 years, a more pronounced seasonality and with reported travel history to/from Tanzania mainland as a higher risk factor. All-cause mortality among children < 5 years decreased by 72% between 2002 and 2007 mainly following the introduction of artemisinin-based combination therapies whereas the main reduction in malaria incidence followed upon the vector control interventions from 2006. Human biting rates decreased by 98% with a major shift towards outdoor biting by Anopheles arabiensis. CONCLUSIONS: Zanzibar provides new evidence of the feasibility of reaching uniquely significant and sustainable malaria reduction (pre-elimination) in a previously high endemic region in sub-Saharan Africa. The data highlight constraints of optimistic prognostic modelling studies. New challenges, mainly with outdoor transmission, a large asymptomatic parasite reservoir and imported infections, require novel tools and reoriented strategies to prevent a rebound effect and achieve elimination.


Asunto(s)
Malaria Falciparum/epidemiología , Malaria Falciparum/prevención & control , Malaria Falciparum/transmisión , Adolescente , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Incidencia , Lactante , Masculino , Prevalencia , Tanzanía/epidemiología
2.
J Antimicrob Chemother ; 74(7): 1890-1893, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-30869127

RESUMEN

BACKGROUND: Delayed parasite clearance and, consequently, reduced efficacy of artemisinin-based combination therapies have been linked with Plasmodium falciparum K13 gene SNPs in Southeast Asia. In Africa, significantly prolonged clearance has not yet been observed and the presently restricted variation in parasite clearance cannot be explained by K13 polymorphisms. OBJECTIVES: Our aim was to study the in vivo pfK13 transcriptional response in patients treated with artemether-lumefantrine and explore whether the pfk13 transcripts can explain the patients' parasite clearance outcomes. PATIENTS AND METHODS: A total of 47 Tanzanian children with microscopically confirmed uncomplicated P. falciparum malaria were hospitalized and received artemether-lumefantrine treatment (clinical trial ID: NCT00336375). RNA was extracted from venous blood samples collected before treatment initiation and at five more timepoints after treatment. cDNA was synthesized and pfk13 transcripts measured by real-time PCR. RESULTS: A wide range of pfk13 transcript variation was observed throughout all timepoints after artemether-lumefantrine treatment. Taking parasite clearance data together with the pfk13 transcripts profile, we observed a negative correlation inferring that pfk13 down-regulation is associated with longer parasite clearance time. CONCLUSIONS: The findings suggest that a reduced PfK13 transcriptional response may represent a first step towards artemisinin tolerance/resistance.


Asunto(s)
Antimaláricos/uso terapéutico , Combinación Arteméter y Lumefantrina/uso terapéutico , Tolerancia a Medicamentos , Expresión Génica , Malaria Falciparum/tratamiento farmacológico , Plasmodium falciparum/efectos de los fármacos , Proteínas Protozoarias/genética , Animales , Antimaláricos/farmacología , Combinación Arteméter y Lumefantrina/farmacología , Niño , Preescolar , Femenino , Perfilación de la Expresión Génica , Humanos , Lactante , Malaria Falciparum/parasitología , Masculino , Tanzanía , Resultado del Tratamiento
3.
Glob Ecol Biogeogr ; 28(2): 78-95, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31007605

RESUMEN

AIM: Plant functional groups are widely used in community ecology and earth system modelling to describe trait variation within and across plant communities. However, this approach rests on the assumption that functional groups explain a large proportion of trait variation among species. We test whether four commonly used plant functional groups represent variation in six ecologically important plant traits. LOCATION: Tundra biome. TIME PERIOD: Data collected between 1964 and 2016. MAJOR TAXA STUDIED: 295 tundra vascular plant species. METHODS: We compiled a database of six plant traits (plant height, leaf area, specific leaf area, leaf dry matter content, leaf nitrogen, seed mass) for tundra species. We examined the variation in species-level trait expression explained by four traditional functional groups (evergreen shrubs, deciduous shrubs, graminoids, forbs), and whether variation explained was dependent upon the traits included in analysis. We further compared the explanatory power and species composition of functional groups to alternative classifications generated using post hoc clustering of species-level traits. RESULTS: Traditional functional groups explained significant differences in trait expression, particularly amongst traits associated with resource economics, which were consistent across sites and at the biome scale. However, functional groups explained 19% of overall trait variation and poorly represented differences in traits associated with plant size. Post hoc classification of species did not correspond well with traditional functional groups, and explained twice as much variation in species-level trait expression. MAIN CONCLUSIONS: Traditional functional groups only coarsely represent variation in well-measured traits within tundra plant communities, and better explain resource economic traits than size-related traits. We recommend caution when using functional group approaches to predict tundra vegetation change, or ecosystem functions relating to plant size, such as albedo or carbon storage. We argue that alternative classifications or direct use of specific plant traits could provide new insights for ecological prediction and modelling.

4.
Antimicrob Agents Chemother ; 56(7): 3615-9, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22508315

RESUMEN

The 4-aminoquinoline bisquinoline piperaquine is an important partner drug in one of the presently recommended artemisinin combination therapies. Recent clinical trials have confirmed its high efficacy in combination with dihydroartemisinin. Resistance to piperaquine alone has, however, been documented. Amplification in copy number of the Plasmodium falciparum multidrug resistance locus on chromosome 5, containing the pfmdr1 gene, has been shown to confer resistance to structurally unrelated antimalarials. Through the determination of the 50% inhibitory concentrations (IC(50)s) and IC(90)s for piperaquine and chloroquine in a set of 46 adapted P. falciparum cultures originating from the Thai-Burmese border, we have characterized the regions around the pfmdr1 gene and identified a significant association between the presence of pfmdr1 duplications and enhanced sensitivity to piperaquine (P = 0.005 for IC(50) and P = 0.002 for IC(90)) and chloroquine, reaching statistical significance at IC(90)s (P = 0.026). These results substantiate the potential importance of pfmdr1 copy number amplifications in the efficacy of the combination therapy piperaquine-dihydroartemisinin. It supports the rational use of 4-aminoquinolines and artemisinin-based compounds, as they independently select for mutually incompatible combinations of mutations.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Antimaláricos/farmacología , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/metabolismo , Quinolinas/farmacología , Transportadoras de Casetes de Unión a ATP/genética , Cloroquina/farmacología , Dosificación de Gen , Plasmodium falciparum/genética , Proteínas Protozoarias/genética
5.
Diabet Med ; 29(12): e449-56, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22998552

RESUMEN

AIMS: To evaluate multi-frequency tactilometry as a method to measure vibrotactile sense in the sole of the foot in subjects with diabetes. METHODS: Vibration thresholds were investigated at five frequencies (8, 16, 32, 64 and 125 Hz) at three sites (first and fifth metatarsal heads and heel) in the sole of the foot in subjects with Type 1 and Type 2 diabetes (n = 37). Thresholds were compared with healthy, age- and gender-matched subjects (n = 37) and related to glycaemic levels, subjective estimation of sensation in the feet and to perception of touch. RESULTS: Vibration thresholds were significantly higher in subjects with diabetes compared with healthy subjects at low frequencies (8, 16 and 32 Hz) at all measured sites, and also at 64 Hz for the metatarsal heads. Perception of touch and subjective estimation of sensation were significantly impaired in subjects with diabetes. Glycaemic levels, which were higher in subjects with diabetes, did not correlate with vibration thresholds at 32 Hz (most sensitive to Meissner's corpuscles) or with touch thresholds in subjects with diabetes. Vibration thresholds at 32 Hz correlated significantly with perception of touch (rho = 0.45-0.65; P < 0.01) and with subjective sensation (rho = -0.38 to -0.52; P < 0.001) in subjects with diabetes. Perception of touch and subjective estimation of sensation did also correlate (rho = -0.51 to -0.80; P < 0.002). CONCLUSIONS: Tactilometry is effective in detecting neuropathy in the sole of the foot at low frequencies of mainly 8-32 Hz, indicating that at least Meissner's corpuscles, or their related large nerve fibres, are affected by diabetes.


Asunto(s)
Neuropatías Diabéticas/fisiopatología , Pie/fisiopatología , Umbral Sensorial , Vibración , Glucemia/metabolismo , Índice de Masa Corporal , Neuropatías Diabéticas/sangre , Neuropatías Diabéticas/diagnóstico , Electrofisiología , Femenino , Pie/inervación , Hemoglobina Glucada/metabolismo , Humanos , Masculino , Mecanorreceptores , Persona de Mediana Edad , Dimensión del Dolor , Valor Predictivo de las Pruebas , Ondas de Radio
6.
Trop Med Int Health ; 17(7): 854-7, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22594779

RESUMEN

Amodiaquine (AQ) is a 4-aminoquinoline widely used in the treatment of malaria as part of the artemisinin combination therapy (ACT). AQ is metabolised towards its main metabolite desethylamodiaquine mainly by cytochrome P450 2C8 (CYP2C8). CYP1A1 and CYP1B1 play a minor role in the metabolism but they seem to be significantly involved in the formation of the short-lived quinine-imine. To complete the genetic variation picture of the main genes involved in AQ metabolism in the Zanzibar population, previously characterised for CYP2C8, we analysed in this study CYP1A1 and CYP1B1 main genetic polymorphisms. The results obtained show a low frequency of the CYP1A1*2B/C allele (2.4%) and a high frequency of CYP1B1*6 (approximately 42%) followed by CYP1B1*2 (approximately 27%) in Zanzibar islands. Genotype data for CYP1A1 and CYP1B1 show a low incidence of fast metabolisers, revealing a relatively safe genetic background in Zanzibar's population regarding the appearance of adverse effects.


Asunto(s)
Aminoquinolinas/metabolismo , Antimaláricos/metabolismo , Hidrocarburo de Aril Hidroxilasas/genética , Citocromo P-450 CYP1A1/genética , Variación Genética , Malaria Falciparum/genética , Alelos , Aminoquinolinas/uso terapéutico , Antimaláricos/uso terapéutico , Hidrocarburo de Aril Hidroxilasas/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1B1 , Femenino , Genotipo , Geografía , Humanos , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/metabolismo , Masculino , Farmacogenética , Polimorfismo Genético , Tanzanía , Adulto Joven
7.
Front Pharmacol ; 13: 868723, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35685627

RESUMEN

Background: Artemisinin-based combination therapies (ACTs) are the global mainstay treatment of uncomplicated Plasmodium falciparum infections. PfMDR1 and PfCRT are two transmembrane transporters, associated with sensitivity to several antimalarials, found in the parasite food vacuole. Herein, we explore if their relatedness extends to overlapping patterns of gene transcriptional activity before and during ACT administration. Methods: In a clinical trial performed in Tanzania, we explored the pfmdr1 and pfcrt transcription levels from 48 patients with uncomplicated P. falciparum malaria infections who underwent treatment with artemether-lumefantrine (AL). Samples analyzed were collected before treatment initiation and during the first 24 h of treatment. The frequency of PfMDR1 N86Y and PfCRT K76T was determined through PCR-RFLP or direct amplicon sequencing. Gene expression was analyzed by real-time quantitative PCR. Results: A wide range of pre-treatment expression levels was observed for both genes, approximately 10-fold for pfcrt and 50-fold for pfmdr1. In addition, a significant positive correlation demonstrates pfmdr1 and pfcrt co-expression. After AL treatment initiation, pfmdr1 and pfcrt maintained the positive co-expression correlation, with mild downregulation throughout the 24 h post-treatment. Additionally, a trend was observed for PfMDR1 N86 alleles and higher expression before treatment initiation. Conclusion: pfmdr1 and pfcrt showed significant co-expression patterns in vivo, which were generally maintained during ACT treatment. This observation points to relevant related roles in the normal parasite physiology, which seem essential to be maintained when the parasite is exposed to drug stress. In addition, keeping the simultaneous expression of both transporters might be advantageous for responding to the drug action.

8.
J Exp Med ; 159(6): 1686-704, 1984 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-6374012

RESUMEN

Monolayers of human erythrocytes (E) infected with Plasmodium falciparum were briefly fixed with 1% glutaraldehyde and air dried. They were then exposed to sera from patients with P. falciparum malaria or from donors immune to this parasite and tested in an indirect immunofluorescence assay (IFA). Parasites in infected E were made visible by counterstaining with ethidium bromide. Immunofluorescence (IF) was restricted to the surface of infected E. No antibody binding was detected unless the E were dried, suggesting that the relevant antigens were not available on the outer layers of the E surface. Staining over large parts of the E surface was seen already when the merozoite penetrated noninfected cells and was strong in E containing early stages of the parasite (rings, trophozoites). It was weak or absent from E containing schizonts. Antibodies in sera from different parts of Africa, Colombia, or Sweden reacted similarly with E infected with a Tanzanian P. falciparum strain kept in culture for many years and with parasitized E freshly drawn from African, Swedish, or Colombian patients. All sera from residents of a holoendemic area (Liberia) were IFA positive. In contrast, some sera from Colombian or Swedish patients with primary infection gave negative results. The results of the IFA and of an enzyme-linked immunosorbent assay in which fixed and dried E were the targets were well-correlated, suggesting that the same antibodies were detected by these assays. The antigens involved in the IFA were susceptible to pronase but not to trypsin or neuraminidase. E surface IF was inhibited by lysates of infected E, merozoite extracts, or soluble antigens present in P. falciparum culture supernatants but not by lysates of normal E or ghost extracts. The inhibitory antigens were heat stable (100 degrees C, 5 min). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblotting of either antigen-enriched preparations from culture supernatants or merozoite extracts showed that antibodies eluted from monolayers of infected E reacted consistently with a predominant polypeptide of Mr 155,000 and two to four minor polypeptides of lower molecular weights. Metabolic labeling of the parasites with 75Se-methionine indicated that these antigens were parasite derived. We conclude that the antigens involved in these reactions are released from bursting schizonts or merozoites and are deposited in the E membrane in the course of invasion.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Antígenos de Superficie/inmunología , Membrana Eritrocítica/parasitología , Malaria/inmunología , Plasmodium falciparum/inmunología , Anticuerpos/inmunología , Antígenos de Superficie/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática , Membrana Eritrocítica/inmunología , Técnica del Anticuerpo Fluorescente , Humanos , Plasmodium falciparum/crecimiento & desarrollo , Pronasa/farmacología
9.
Diabet Med ; 27(7): 823-9, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20636964

RESUMEN

AIMS: Impaired sensory function in the sole of the foot in diabetic patients is a substantial problem caused by unknown mechanisms. Hand or foot sensibility can be improved by cutaneous anaesthesia of the forearm or lower leg, respectively, in healthy subjects. Hypothetically, cutaneous anaesthesia induces a silent area in the primary somatosensory cortex, allowing adjacent cortical areas to expand; thus, resulting in enhanced sensory processing. Our aim was to improve sensory function in the foot in Type 1 and Type 2 diabetic patients by application of an anaesthetic cream to the lower leg. METHODS: In a double-blind study, 37 patients with Type 1 or Type 2 diabetes were randomly assigned to cutaneous application of either an anaesthetic cream (EMLA) or a placebo cream to the skin of the lower leg for 1.5 h. Sensibility at five points of the sole of the foot was assessed before and after 1.5 and 24 h. Vibrotactile sense was also assessed. Primary outcome was change of touch threshold at the first metatarsal head from pretreatment to 1.5 h assessment. RESULTS: Anaesthetic cream on the lower leg resulted in a significant improvement of touch threshold at the first metatarsal head after 1.5 and 24 h. In addition, improvement of touch thresholds was also observed at the other four assessment sites, together with a decreased vibration threshold at 125 Hz. CONCLUSIONS: The findings of improved touch thresholds open up new possibilities in treatment of sensibility disturbances in the diabetic foot, using a simple and non-invasive method.


Asunto(s)
Anestésicos Locales/uso terapéutico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Pie Diabético/tratamiento farmacológico , Dolor/tratamiento farmacológico , Umbral Sensorial/efectos de los fármacos , Anciano , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Pie Diabético/fisiopatología , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/fisiopatología , Suecia , Resultado del Tratamiento
10.
Nat Commun ; 11(1): 1351, 2020 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-32165619

RESUMEN

The majority of variation in six traits critical to the growth, survival and reproduction of plant species is thought to be organised along just two dimensions, corresponding to strategies of plant size and resource acquisition. However, it is unknown whether global plant trait relationships extend to climatic extremes, and if these interspecific relationships are confounded by trait variation within species. We test whether trait relationships extend to the cold extremes of life on Earth using the largest database of tundra plant traits yet compiled. We show that tundra plants demonstrate remarkably similar resource economic traits, but not size traits, compared to global distributions, and exhibit the same two dimensions of trait variation. Three quarters of trait variation occurs among species, mirroring global estimates of interspecific trait variation. Plant trait relationships are thus generalizable to the edge of global trait-space, informing prediction of plant community change in a warming world.


Asunto(s)
Desarrollo de la Planta , Tundra , Clima , Ecosistema , Plantas/clasificación , Plantas/genética
11.
Science ; 231(4733): 57-9, 1986 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-3510452

RESUMEN

Pf 155, a protein of the human malaria parasite Plasmodium falciparum, is strongly immunogenic in humans and is believed to be a prime candidate for the preparation of a vaccine. Human monoclonal antibodies to Pf 155 were obtained by cloning B cells that had been prepared from an immune donor and transformed with Epstein-Barr virus. When examined by indirect immunofluorescence, these antibodies stained the surface of infected erythrocytes, free merozoites, segmented schizonts, and gametocytes. They bound to a major polypeptide with a relative molecular weight of 155K and to two minor ones (135K and 120K), all having high affinity for human glycophorin. The antibodies strongly inhibited merozoite reinvasion in vitro, suggesting that they might be appropriate reagents for therapeutic administration in vivo.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Antígenos de Protozoos/inmunología , Plasmodium falciparum/inmunología , Animales , Anticuerpos Monoclonales/uso terapéutico , Antígenos de Protozoos/análisis , Humanos , Vacunas/inmunología
12.
Eur J Clin Pharmacol ; 65(4): 355-63, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18979093

RESUMEN

AIM: The aim of this study was to obtain pharmacogenetic data in a Vietnamese population on genes coding for proteins involved in the elimination of drugs currently used for the treatment of malaria and human immunodeficiency virus/acquired immunodeficiency syndrome. METHOD: The main polymorphisms on the cytochrome P450 (CYP) genes, CYP2A6, CYP2B6, CYP2C19, CYP2D6, CYP3A4 and CYP3A5, and the multi-drug resistance 1 gene (MDR1) were genotyped in 78 healthy Vietnamese subjects. Pharmacokinetic metrics were available for CYP2A6 (coumarin), CYP2C19 (mephenytoin), CYP2D6 (metoprolol) and CYP3As (midazolam), allowing correlations with the determined genotype. RESULTS: In the CYP2 family, we detected alleles CYP2A6*4 (12%) and *5 (15%); CYP2B6*4 (8%), *6 (27%); CYP2C19*2 (31%) and *3 (6%); CYP2D6*4, *5, *10 (1, 8 and 44%, respectively). In the CYP3A family, CYP3A4*1B was detected at a low frequency (2%), whereas CYP3A5 *3 was detected at a frequency of 67%. The MDR1 3435T allele was present with a prevalence of 40%. Allele proportions in our cohort were compared with those reported for other Asian populations. CYP2C19 genotypes were associated to the S-4'-OH-mephenytoin/S-mephenytoin ratio quantified in plasma 4 h after intake of 100 mg mephenytoin. While CYP2D6 genotypes were partially reflected by the alpha-OH-metroprolol/metoprolol ratio in plasma 4 h after dosing, no correlation existed between midazolam plasma concentrations 4 h post-dose and CYP3A genotypes. CONCLUSIONS: The Vietnamese subjects of our study cohort presented allele prevalences in drug-metabolising enzymes that were generally comparable with those reported in other Asian populations. Deviations were found for CYP2A6*4 compared to a Chinese population (12 vs. 5%, respectively; P = 0.023), CYP2A6*5 compared with a Korean population (15 vs. <1%, respectively; P < 0.0001), a Malaysian population (1%; P < 0.0001) and a Chinese population (1%; P < 0.0001); CYP2B6*6 compared with a Korean population (27 vs. 12%; P = 0.002) and a Japanese population (16%; P = 0.021). Pharmacokinetic metrics versus genotype analysis reinforces the view that the predictive value of certain globally common variants (e.g. CYP2D6 single nucleotide polymorphisms) should be evaluated in a population-specific manner.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Hidrocarburo de Aril Hidroxilasas/genética , Pueblo Asiatico/genética , Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP3A/genética , Oxidorreductasas N-Desmetilantes/genética , Polimorfismo Genético , Subfamilia B de Transportador de Casetes de Unión a ATP , Citocromo P-450 CYP2A6 , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP2C19 , Frecuencia de los Genes , Genotipo , Humanos , Farmacogenética , Vietnam
13.
J Wrist Surg ; 7(5): 382-388, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30349750

RESUMEN

Background Magnetic resonance (MR) is the most important imaging technique to assess intra-articular pathology of the wrist. Among various MR imaging protocols, the diagnostic performance of indirect MR arthrography needs further investigation. Purpose The purpose of this study was to assess the diagnostic performance of pre- and postcontrast, 3 T indirect MR arthrography in the diagnosis of scapholunate intrinsic ligament (SLIL) and triangular fibrocartilage complex (TFCC) injuries, using wrist arthroscopy as reference standard. Patients and Methods We retrospectively evaluated consecutive patients with suspected SLIL or TFCC injury, who had indirect MR arthrography done before arthroscopy. Images were assessed independently by two senior radiologists. Results Arthroscopy of the 53 wrists demonstrated 16 Geissler stages II and III partial tears and 6 stage IV total SLIL ruptures. Central perforation of the TFCC was found in 24 wrists, and 12 wrists had an ulnar class 1B lesion. To detect any SLIL tear, accuracy was higher for the two observers using postcontrast indirect MR arthrography (0.77 and 0.72) than for precontrast MR imaging (0.60 and 0.60). No difference was found for total SLIL ruptures "0.85 and 0.89" versus "0.85 and 0.89." To diagnose class 1B TFCC injuries, accuracy was higher using postcontrast indirect MR arthrography (0.85 and 0.75) than for precontrast MR imaging (0.70 and 0.72). No difference in accuracy was demonstrated for TFCC central tears "0.75 and 0.75" versus "0.70 and 0.77." Conclusion Postcontrast images at 3 T indirect MR arthrography, compared with precontrast images, have an improved diagnostic performance for the overall detection of SLIL injuries and as well as class 1B TFCC tears. Level of Evidence This is a Level II, diagnostic study.

14.
J Pharm Biomed Anal ; 45(2): 282-7, 2007 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-17719735

RESUMEN

A bioanalytical method for the determination of lumefantrine in 100 microl blood applied onto sampling paper, by solid-phase extraction and liquid chromatography, has been developed and validated. Whatman 31 ET Chr sampling paper was pre-treated with 0.75 M tartaric acid before sampling capillary blood to enable a high recovery of lumefantrine. Lumefantrine was extracted from the sampling paper, then further purified using solid-phase extraction and finally quantified with HPLC. The between-day variation was below 10% over the range 0.4-25 microM. The lower limit of quantification was 0.25 microM in 100 microl capillary blood. No decrease in lumefantrine concentration in dried blood spot is seen after 4 months storage at 22 degrees C. The method was also evaluated in field samples from patients in Tanzania after treatment with lumefantrine/artemether. Lumefantrine could be estimated accurately enough to assess bioavailability and treatment compliance on day 7 (i.e. 4 days after the last dose) after a standard regimen with the lumefantrine/artemether combination.


Asunto(s)
Antimaláricos/sangre , Antimaláricos/aislamiento & purificación , Cromatografía Liquida/métodos , Etanolaminas/sangre , Etanolaminas/aislamiento & purificación , Fluorenos/sangre , Fluorenos/aislamiento & purificación , Humanos , Lumefantrina , Papel , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Extracción en Fase Sólida
15.
Acta Neurochir Suppl ; 100: 121-6, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17985560

RESUMEN

BACKGROUND: We describe a new principle for enhancing the effects of sensory re-education following nerve injury and repair. The outcome from nerve repair in adult patients is generally poor. One reason is the functional cortical reorganisation which always occurs because of axonal misdirection at the repair site. In healthy individuals selective anaesthesia of the forearm results in improved hand sensation. Here we hypothesised that this principle would be valid also after nerve injury and repair. METHOD: In a prospective, randomised, double blind study we studied the effects of cutaneous forearm anaesthesia combined with sensory reeducation on the outcome after median or ulnar nerve repair at wrist or distal forearm level. FINDINGS: EMLA-application four times over a two week period starting with beginning reinnervation of the fingers resulted in significantly improved sensory recovery (tactile gnosis) as compared to the placebo group and also at assessment four weeks after the last EMLA-session. However, at assessment 8-11 months after the first EMLA-treatment there was no difference between the groups. CONCLUSIONS: Our findings indicate that repeated cutaneous forearm anaesthesia over a two week period can enhance the effects of sensory re-education at least over the four following weeks. However, the optimal time protocol for EMLA-treatment, aiming at a long-lasting or permanent effect on sensory recovery still has to be defined.


Asunto(s)
Anestesia Local , Antebrazo , Aprendizaje , Nervio Mediano/lesiones , Procedimientos Neuroquirúrgicos/rehabilitación , Sensación , Piel , Nervio Cubital/lesiones , Adulto , Anciano , Anestésicos Locales , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Lidocaína , Combinación Lidocaína y Prilocaína , Masculino , Nervio Mediano/cirugía , Persona de Mediana Edad , Prilocaína , Recuperación de la Función , Tacto , Nervio Cubital/cirugía , Heridas y Lesiones/cirugía , Muñeca/inervación
16.
Acta Neurochir Suppl ; 100: 109-12, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17985557

RESUMEN

BACKGROUND: Following a peripheral nerve repair the injured nerve has to re-innervate its original cortical area, a process, which is poorly understood. Errors in this cortical re-innervation have been suggested as one key reason for the generally poor clinical outcome following nerve injuries in the hand. METHOD: Functional magnetic resonance imaging (fMRI) was used to assess cortical reintegration following amputation and reattachment of bodyparts in two different situations: a patient with a hand amputation followed by immediate surgical replantation and a patient with an osseointegrated thumb prosthesis. FINDINGS: The primary motor cortex rapidly returns to a normal activation pattern after amputation followed by replantation or application of an osseointegrated prosthesis. The primary somatosenory cortex changes from an initial ipsilateral to a bilateral activation pattern. Sensory stimulation of an osseointegrated prosthesis also shows a bilateral activation pattern in the primary somatosenory cortex. CONCLUSIONS: The primary motor cortex shows a more normal activation pattern possibly because most muscles controlling the hand are proximal to the injury and can be activated after an amputation. The primary somatosensory cortex reorganises more and the activation pattern is more bilateral compared to a healthy hand. This bilateral activation pattern could represent a compensatory mechanism for the inferior tactile function in the replanted hand and the osseointegrated prosthesis.


Asunto(s)
Encéfalo/fisiopatología , Mano/fisiopatología , Mano/cirugía , Oseointegración , Prótesis e Implantes , Reimplantación , Pulgar , Anciano , Amputación Traumática/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Corteza Motora/fisiopatología , Sensación , Corteza Somatosensorial/fisiopatología
17.
J Vet Intern Med ; 31(6): 1771-1781, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28892202

RESUMEN

BACKGROUND: Chiari-like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels and Griffon Bruxellois dogs. Increasing evidence indicates that CM and SM also occur in other small and toy breed dogs, such as Chihuahuas. OBJECTIVES: To describe the presence of SM and craniocervical junction (CCJ) abnormalities in Chihuahuas and to evaluate the possible association of CCJ abnormalities with SM. To describe CM/SM-related clinical signs and neurologic deficits and to investigate the association of CM/SM-related clinical signs with signalment, SM, or CCJ abnormalities. ANIMALS: Fifty-three client-owned Chihuahuas. METHODS: Prospective study. Questionnaire analyses and physical and neurologic examinations were obtained before magnetic resonance and computed tomography imaging. Images were evaluated for the presence of SM, CM, and atlantooccipital overlapping. Additionally, medullary kinking, dorsal spinal cord compression, and their sum indices were calculated. RESULTS: Scratching was the most common CM/SM-related clinical sign and decreased postural reaction the most common neurologic deficit in 73 and 87% of dogs, respectively. Chiari-like malformation and SM were present in 100 and 38% of dogs, respectively. Syringomyelia was associated with the presence of CM/SM-related clinical signs (P = 0.034), and medullary kinking and sum indices were higher in dogs with clinical signs (P = 0.016 and P = 0.007, respectively). CONCLUSIONS AND CLINICAL IMPORTANCE: Syringomyelia and CCJ abnormalities are prevalent in Chihuahuas. Syringomyelia was an important factor for the presence of CM/SM-related clinical signs, but many dogs suffered from similar clinical signs without being affected by SM, highlighting the clinical importance of CCJ abnormalities in Chihuahuas.


Asunto(s)
Malformación de Arnold-Chiari/veterinaria , Enfermedades de los Perros/congénito , Siringomielia/veterinaria , Animales , Malformación de Arnold-Chiari/diagnóstico por imagen , Articulación Atlantooccipital/anomalías , Articulación Atlantooccipital/diagnóstico por imagen , Enfermedades de los Perros/diagnóstico por imagen , Perros , Femenino , Imagen por Resonancia Magnética/veterinaria , Masculino , Bulbo Raquídeo/patología , Estudios Prospectivos , Especificidad de la Especie , Compresión de la Médula Espinal/diagnóstico por imagen , Siringomielia/diagnóstico por imagen , Tomografía Computarizada por Rayos X/veterinaria
18.
Malar J ; 5: 7, 2006 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-16451728

RESUMEN

Analysis of malaria imported into eight European countries from the Indian Sub-continent (ISC) (India, Pakistan, Bangladesh and Sri Lanka) led to a consensus statement on the use of chemoprophylaxis within TropNetEurop. The proportion of cases from the ISC in 2004 ranged from 1.4%-4.6% of total imported cases. Plasmodium falciparum cases reported from the eight countries was only 23 (13% of all cases from the region). Total malaria reports between 1999-2004 fell from 317 to 180. The risk of malaria in UK residents visiting the region was > 1 case per 1,000 years exposed. The group recommended non-selective prescribing of chemoprophylaxis for visitors to India, Pakistan, Bangladesh and Sri Lanka should be dropped.


Asunto(s)
Antimaláricos/uso terapéutico , Malaria/prevención & control , Viaje/tendencias , Animales , Antimaláricos/administración & dosificación , Bangladesh/epidemiología , Redes de Comunicación de Computadores , Europa (Continente)/epidemiología , Humanos , India/epidemiología , Malaria/tratamiento farmacológico , Malaria/epidemiología , Pakistán/epidemiología , Plasmodium falciparum/aislamiento & purificación , Sri Lanka/epidemiología
19.
Acta Trop ; 97(3): 352-6, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16490179

RESUMEN

Plasmodium falciparum resistance to chloroquine (CQ) has been documented in Iran since the early 1980s and has since gradually increased. Iran is therefore reviewing its national drug policy for malaria control. We describe the prevalence of single nucleotide polymorphisms (SNP) associated with quinoline drug resistance in south eastern Iran. Pre-treatment blood from patients with uncomplicated but symptomatic P. falciparum infection was analysed. Polymorphisms at codons 76, 152, 163 and 220 of the pfcrt gene (chloroquine resistance transporter) and at codons 86, 184, 1034, 1042 and 1246 of the pfmdr1 gene (multidrug resistance) were determined by PCR-RFLP and sequencing. In addition, SNPs on a recently described multidrug resistance protein (pfmrp) and a microsatellite (MS-4760) in the pfnhe-1 (sodium hydrogen exchanger) gene associated with quinoline and quinine resistance, respectively, were investigated for the first time in field samples not from Thailand. pfcrt 76T was found in 99% and pfmdr1 86Y in 72% of the samples. pfmrp 191H and 437S associated with decreased quinoline response were found to be absolutely linked at a frequency of 13.6%. The pfnhe-1 MS-4760 one repeat allele associated to quinine response in vitro was also detected. Sequencing of the pfcrt 72-76 haplotype revealed that SVMNT was the most common allele as previously observed in India. This suggests that pfcrt found in the Iranian P. falciparum population may have the same origin as in the P. falciparum populations in India but different from that normally found in south east Asia. In conclusion, the frequencies of quinoline resistance associated gene polymorphisms in this region suggest a population that has been significantly selected for by the long use of CQ.


Asunto(s)
Resistencia a Medicamentos/genética , Genes Protozoarios/genética , Proteínas de la Membrana/genética , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Polimorfismo Genético/genética , Quinolinas/farmacología , Adolescente , Adulto , Anciano , Animales , Antimaláricos/farmacología , Niño , Preescolar , Humanos , Irán , Malaria Falciparum/parasitología , Proteínas de Transporte de Membrana , Persona de Mediana Edad , Proteínas Protozoarias
20.
J Hand Surg Br ; 31(2): 126-32, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16352379

RESUMEN

The outcome after nerve repair in adults is generally poor. We hypothesized that forearm deafferentation would enhance the sensory outcome by increasing the cortical hand representation. A prospective, randomized, double-blind study was designed to investigate the effects of cutaneous forearm anaesthesia combined with sensory re-education on the outcome after ulnar or median nerve repair. During a 2 week period, a local anaesthetic cream (EMLA (n = 7) or placebo (n=6) was applied repeatedly onto the flexor aspect of the forearm of the injured arm and combined with sensory re-education. Evaluation of sensory function was carried out at regular intervals and at 4 weeks after the last EMLA/placebo session. The EMLA group showed significant improvement compared to placebo in perception of touch/pressure, tactile gnosis and in the summarized outcome after 6 weeks. These results suggest that cutaneous forearm anaesthesia of the injured limb, in combination with sensory re-education, can enhance sensory recovery after nerve repair.


Asunto(s)
Anestésicos Locales/uso terapéutico , Mano/inervación , Aprendizaje , Lidocaína/uso terapéutico , Percepción/efectos de los fármacos , Prilocaína/uso terapéutico , Trastornos de la Sensación/rehabilitación , Sensación/efectos de los fármacos , Piel/inervación , Tacto/fisiología , Adulto , Anciano , Método Doble Ciego , Femenino , Antebrazo/inervación , Antebrazo/cirugía , Mano/fisiopatología , Humanos , Combinación Lidocaína y Prilocaína , Masculino , Nervio Mediano/lesiones , Nervio Mediano/cirugía , Persona de Mediana Edad , Plasticidad Neuronal , Estudios Prospectivos , Trastornos de la Sensación/fisiopatología , Piel/efectos de los fármacos , Nervio Cubital/lesiones , Nervio Cubital/cirugía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA