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1.
Antimicrob Agents Chemother ; 54(5): 2135-42, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20194689

RESUMEN

This study describes the results of in vitro antimalarial susceptibility assays and molecular polymorphisms of Plasmodium falciparum isolates from Cambodia. The samples were collected from patients enrolled in therapeutic efficacy studies (TES) conducted by the Cambodian National Malaria Control Program for the routine efficacy monitoring of artemisinin-based combination therapy (ACT) (artesunate-mefloquine and artemether-lumefantrine combinations). The isolates (n = 2,041) were obtained from nine sentinel sites during the years 2001 to 2007. Among these, 1,588 were examined for their in vitro susceptibilities to four antimalarials (artesunate, mefloquine, chloroquine, and quinine), and 851 isolates were genotyped for single nucleotide polymorphisms (SNPs). The geometric means of the 50% inhibitory concentrations (GMIC(50)s) of the four drugs tested were significantly higher for isolates from western Cambodia than for those from eastern Cambodia. GMIC(50)s for isolates from participants who failed artesunate-mefloquine therapy were significantly higher than those for patients who were cured (P, <0.001). In vitro correlation of artesunate with the other drugs was observed. The distributions of the SNPs differed between eastern and western Cambodia, suggesting different genetic backgrounds of the parasite populations in these two parts of the country. The GMIC(50)s of the four drugs tested increased significantly in eastern Cambodia during 2006 to 2007. These results are worrisome, because they may signal deterioration of the efficacy of artesunate-mefloquine beyond the Cambodian-Thai border.


Asunto(s)
Antimaláricos/farmacología , Artemisininas/farmacología , Farmacorresistencia Bacteriana/genética , Malaria Falciparum/tratamiento farmacológico , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Artesunato , Cambodia , Cloroquina/farmacología , Sistemas de Información Geográfica , Técnicas In Vitro , Concentración 50 Inhibidora , Mefloquina/farmacología , Análisis de Secuencia por Matrices de Oligonucleótidos , Plasmodium falciparum/crecimiento & desarrollo , Mutación Puntual , Polimorfismo de Nucleótido Simple , Quinina/farmacología
2.
Exp Biol Med (Maywood) ; 232(3): 454-60, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17327480

RESUMEN

Cryptosporidium parvum is a parasitic protozoa increasingly appreciated as a cause of intestinal malabsorptive syndrome leading to malnutrition and/or growth failure. Because a major mechanism for apical peptide absorption by small intestine is via the proton-coupled transporter PepT1, we investigated the expression and functionality of this transporter in our model of acute cryptosporidiosis. Four-day-old Sprague-Dawley rats were inoculated by gavage with 5 x 10(5) oocysts of C. parvum and killed at Day 12 (peak of the infection) or Day 21 (spontaneous clearance of the parasite). PepT1 expression and functionality were quantified in the distal small intestine, preferential site of C. parvum implantation, and in the proximal small intestine, free of parasite, using Western blot and Ussing chambers, respectively. No difference in total PepT1 protein expression or in glycyl-sarcosine fluxes was observed in C. parvum-infected rats compared with controls either on Day 12 or on Day 21, both in the proximal and in the distal small intestine. However, a significant decrease of apical membrane protein expression of PepT1 was observed in C. parvum-infected enterocytes compared with controls. This maintained dipeptide transport observed despite villous atrophy and decreased expression of the protein at the brush-border membrane strongly suggest a transient upregulation of PepT1 activity, probably related to gamma-interferon regulation.


Asunto(s)
Criptosporidiosis/metabolismo , Cryptosporidium parvum/crecimiento & desarrollo , Simportadores/metabolismo , Animales , Animales Lactantes , Western Blotting , Criptosporidiosis/sangre , Criptosporidiosis/parasitología , Dipéptidos/metabolismo , Enterocitos/metabolismo , Enterocitos/parasitología , Íleon/metabolismo , Íleon/parasitología , Interferón gamma/sangre , Interferón gamma/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/parasitología , Microvellosidades/metabolismo , Microvellosidades/parasitología , Transportador de Péptidos 1 , Ratas , Ratas Sprague-Dawley , Regulación hacia Arriba
3.
Clin Chem Lab Med ; 44(1): 110-20, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16375596

RESUMEN

The EC4 Syllabus for Postgraduate Training is the basis for the European Register of Specialists in Clinical Chemistry and Laboratory Medicine. The syllabus: Indicates the level of requirements in postgraduate training to harmonise the postgraduate education in the European Union (EU); Indicates the level of content of national training programmes to obtain adequate knowledge and experience; Is approved by all EU societies for clinical chemistry and laboratory medicine. The syllabus is not primarily meant to be a training guide, but on the basis of the overview given (common minimal programme), national societies should formulate programmes that indicate where knowledge and experience is needed. The main points of this programme are: Indicates the level of requirements in postgraduate training to harmonise the postgraduate education in the European Union (EU); Indicates the level of content of national training programmes to obtain adequate knowledge and experience; Is approved by all EU societies for clinical chemistry and laboratory medicine. Knowledge in biochemistry, haematology, immunology, etc.; Pre-analytical conditions; Evaluation of results; Interpretations (post-analytical phase); Laboratory management; and Quality insurance management. The aim of this version of the syllabus is to be in accordance with the Directive of Professional Qualifications published on 30 September 2005. To prepare the common platforms planned in this directive, the disciplines are divided into four categories: Indicates the level of requirements in postgraduate training to harmonise the postgraduate education in the European Union (EU); Indicates the level of content of national training programmes to obtain adequate knowledge and experience; Is approved by all EU societies for clinical chemistry and laboratory medicine. Knowledge in biochemistry, haematology, immunology, etc.; Pre-analytical conditions; Evaluation of results; Interpretations (post-analytical phase); Laboratory management; and Quality insurance management. General chemistry, encompassing biochemistry, endocrinology, chemical (humoral), immunology, toxicology, and therapeutic drug monitoring; Haematology, covering cells, transfusion serology, coagulation, and cellular immunology; Microbiology, involving bacteriology, virology, parasitology, and mycology; Genetics and IVF.


Asunto(s)
Química Clínica/educación , Curriculum , Educación Médica Continua/métodos , Química/educación , Química Clínica/normas , Educación Médica Continua/normas , Europa (Continente) , Genética/educación , Hematología/educación , Humanos , Laboratorios , Microbiología/educación , Publicaciones Periódicas como Asunto , Control de Calidad , Investigación , Libros de Texto como Asunto , Factores de Tiempo
4.
Parasitol Res ; 96(5): 326-30, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15924222

RESUMEN

This study aimed to explore the metabolic consequences of cryptosporidiosis in an acute experimental model both at the peak of infection and after parasite clearance. Four-day-old suckling rats were infected with 10(6) oocysts of Cryptosporidium parvum. At the peak of infection (day 8 PI), C. parvum resulted in a dramatic reduction both in nutrient intake (-50%) and body weight (16.3+/-5.2 vs 27.3+/-1.0 g, P<0.01) with a decrease in both lean body mass and adipose tissue. Muscular fractional and absolute synthesis rate were reduced (-15 and -55%, respectively). After parasite clearance (day 17 PI), body weight remained reduced in formerly infected animals (37.8+/-8.0 vs 47.8+/-4.2 g, P<0.01) whereas nutrient intake normalized and fractional synthesis rate slightly increased (+22%) compared to controls. Overall, our results show that the impact and consequences of cryptosporidiosis are far greater than generally appreciated, leading to major malnutrition in suckling rats.


Asunto(s)
Criptosporidiosis/metabolismo , Criptosporidiosis/patología , Cryptosporidium parvum , Músculo Esquelético/metabolismo , Proteínas/metabolismo , Animales , Animales Lactantes , Modelos Animales de Enfermedad , Femenino , Ratas , Ratas Sprague-Dawley , Pérdida de Peso
5.
Antimicrob Agents Chemother ; 48(2): 538-45, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14742207

RESUMEN

The protease inhibitor saquinavir was administered to 100 human immunodeficiency virus type 1 (HIV-1)-infected patients as a single 600-mg oral dose (hard gelatin capsules) with a standard breakfast, including 200 ml of grapefruit juice, during an open-label trial to assess whether diarrhea and/or wasting syndrome has consequences on its pharmacokinetics. Three groups of patients were enrolled: group 1, asymptomatic patients (n = 30); group 2, AIDS symptomatic patients without body weight loss or diarrhea (n = 37); and group 3, AIDS symptomatic patients with severe body weight loss and/or diarrhea (n = 33). Clinical and biological data (covariates) were collected. A population approach was performed with three blood samples per patient to estimate the mean population pharmacokinetic parameters (clearance [CL]/oral bioavailability [F], V/F, k(a), and lag time) and the derived ones (k(el), C(max), T(max), and area under the curve [AUC]). The relationships between groups, exposure (i.e., estimated individual post hoc AUCs), and covariates were explored by using multiple linear regressions. A significant increase in median AUCs (165, 349, and 705 ng. h. ml(-1) for groups 1, 2, and 3, respectively [P < 0.0001]) was observed. The enhancement in saquinavir exposure could be due to the destruction of the transporters in enterocytes and/or to the enlargement of their tight junctions, allowing a paracellular crossing of saquinavir as the illness spreads. Because of grapefruit juice intake by every patient, no implication of CYP3A4 could be assessed. These results strongly suggest that, despite its low intrinsic oral bioavailability, saquinavir can be considered as a relevant treatment for HIV-1-infected patients with diarrhea and/or wasting syndrome. This must be evaluated in a long-term period.


Asunto(s)
Fármacos Anti-VIH/farmacocinética , Diarrea/metabolismo , Infecciones por VIH/metabolismo , Síndrome de Emaciación por VIH/metabolismo , VIH-1 , Saquinavir/farmacocinética , Adulto , Análisis de Varianza , Diarrea/etiología , Femenino , Infecciones por VIH/complicaciones , Humanos , Masculino , Modelos Biológicos , Población
6.
J Pediatr Gastroenterol Nutr ; 36(5): 632-6, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12717087

RESUMEN

OBJECTIVES: To evaluate the efficacy and toxicity of infliximab in children with severe Crohn disease (CD), the authors prospectively monitored 21 children aged 15 +/- 2 years with severe CD who they treated with infliximab (5 mg/kg) on days 0, 15, and 45. One patient received only one injection. Eighteen patients were corticosteroid dependent, and 6 were receiving parenteral nutrition. Three patients were corticoid resistant (1 mg/kg/d >15 days). Sixteen had perianal disease. RESULTS: The Harvey-Bradshaw index (HB) decreased from 8 +/- 3 on day 0 to 1 +/- 2 on day 45 (P = 0.001). The inflammation factors decreased (P = 0.001), and albumin increased (P = 0.002). Nineteen children were in complete remission (HB < 4) on day 45, and 2 had improved (HB = -6 points). Tumor necrosis factor-alpha (TNFalpha) in the stools (n = 16) decreased (P = 0.04). All perianal fistulas (n = 12) were closed by day 90. Fourteen of 21 patients had stopped taking steroids at 3 months, and all had stopped parenteral nutrition. Growth velocity was significantly greater after infliximab administration (Z score, +0.5) than before (-0.45; P = 0.004). Nineteen of 21 patients had relapsed (90%) at 1 year despite continued immunosuppressors. Seven had surgery because of an uncontrolled relapse ( 5), stenosis ( 1), or fistula ( 1). Six patients developed antinuclear antibodies (1/40-1/640e), and two had anti-DNA antibodies. Epstein-Barr virus (EBV) polymerase chain reaction (PCR) values increased (>100-fold) in eight patients. One child developed an anaphylactic reaction to the medication, and one had a catheter-related sepsis. CONCLUSION: Infliximab produces spectacular results for children with severe CD and is well tolerated. However, its effect is transitory for many (90%), with frequent relapses despite continued immunosuppressors. Long-term management with infliximab should be tested despite its worrying side effects.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Enfermedad de Crohn/terapia , Factor de Necrosis Tumoral alfa/inmunología , Adolescente , Corticoesteroides/uso terapéutico , Anticuerpos Monoclonales/efectos adversos , Enfermedad de Crohn/cirugía , Enfermedad de Crohn/virología , Heces/química , Femenino , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Infliximab , Masculino , Estudios Prospectivos , Recurrencia , Inducción de Remisión , Factor de Necrosis Tumoral alfa/análisis
7.
N Engl J Med ; 346(25): 1963-9, 2002 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-12075057

RESUMEN

BACKGROUND: Intestinal microsporidiosis due to Enterocytozoon bieneusi is a cause of chronic diarrhea, malabsorption, and wasting in immunocompromised patients. Currently, there is no effective treatment. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of fumagillin (60 mg per day orally for two weeks) in patients with chronic E. bieneusi infection. Efficacy was assessed primarily by the clearance of microsporidia, as evidenced by analysis of stool specimens. Patients in whom microsporidia were not cleared received treatment for two weeks with open-label fumagillin. After clearance of the parasite, follow-up stool examinations were performed monthly to detect relapses. RESULTS: Twelve patients were enrolled in this study, 10 with the acquired immunodeficiency syndrome and 2 who had received organ transplants. Clearance of microsporidia occurred in all six of the patients in the fumagillin group, as compared with none of the six in the placebo group (P=0.002). Treatment with fumagillin was also associated with increases in absorption of D-xylose (P=0.003) and in Karnofsky performance scores (P<0.001) and with decreases in loperamide use (P=0.01) and total stool weight (P=0.04). There were serious adverse events (neutropenia and thrombocytopenia) in three patients in the fumagillin group; one patient in the placebo group had severe diarrhea. All six controls subsequently had clearance of microsporidia after open-label treatment with fumagillin. Relapses of the infection were identified in two patients during follow-up (median follow-up, 10 months). CONCLUSIONS: Fumagillin is an effective treatment for chronic E. bieneusi infection in immunocompromised patients.


Asunto(s)
Antiprotozoarios/uso terapéutico , Enterocytozoon , Ácidos Grasos Insaturados/uso terapéutico , Parasitosis Intestinales/tratamiento farmacológico , Microsporidiosis/tratamiento farmacológico , Infecciones Oportunistas/tratamiento farmacológico , Adulto , Antiprotozoarios/efectos adversos , Enfermedad Crónica , Ciclohexanos , Método Doble Ciego , Enterocytozoon/aislamiento & purificación , Ácidos Grasos Insaturados/efectos adversos , Heces/parasitología , Humanos , Huésped Inmunocomprometido , Parasitosis Intestinales/diagnóstico , Masculino , Microsporidiosis/diagnóstico , Sesquiterpenos
8.
J Nutr ; 132(5): 1009-11, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11983829

RESUMEN

The ontogenetic development of PepT1, NBAT and EAAC1 along the vertical and horizontal axes of the rat small intestine was evaluated using semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. The proximodistal profiles of mRNA levels showed that PepT1 was evenly distributed, whereas NBAT had greater expression in the proximal part, and EAAC1 in the distal part. These regionalizations were the same from postnatal days 4 to 50. PepT1 and NBAT proteins were detected in the microvilli of enterocytes along the length of the villi. NBAT was also found in the cytoplasm. Surprisingly, EAAC1 was located exclusively in the microvilli of enterocytes in the crypt and the bases of the villi. These protein expression patterns were similar in all parts of the small intestine (proximal, median and distal), at all ages. We conclude that the expression of PepT1, NBAT or EAAC1 are differently regulated according to both the horizontal and vertical axes.


Asunto(s)
Envejecimiento/metabolismo , Sistema de Transporte de Aminoácidos X-AG , Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Proteínas Portadoras/metabolismo , Intestino Delgado/crecimiento & desarrollo , Simportadores , Sistemas de Transporte de Aminoácidos Básicos/genética , Sistemas de Transporte de Aminoácidos Neutros/genética , Animales , Animales Recién Nacidos , Proteínas Portadoras/genética , Enterocitos/metabolismo , Transportador 3 de Aminoácidos Excitadores , Femenino , Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas de Transporte de Glutamato en la Membrana Plasmática , Inmunohistoquímica , Absorción Intestinal/fisiología , Intestino Delgado/metabolismo , Masculino , Microvellosidades/metabolismo , Transportador de Péptidos 1 , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Distribución Tisular
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