Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
medRxiv ; 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38496497

RESUMEN

Background: The primary barrier to curing HIV infection is the pool of intact HIV proviruses integrated into host cell DNA throughout the bodies of people living with HIV (PLHIV), called the HIV reservoir. Reservoir size is impacted by the duration of HIV infection, delay in starting antiretroviral therapy (ART), and breakthrough viremia during ART. The leading infectious cause of death worldwide for PLHIV is TB, but we don't know how TB impacts the HIV reservoir. Methods: We designed a case-control study to compare HIV provirus-containing CD4 in PLHIV with vs. without a history of active TB disease. Study participants in the pilot and confirmatory cohort were enrolled at GHESKIO Centers in Port au Prince, Haiti. Intact and non-intact proviral DNA were quantified using droplet digital PCR of PBMC-derived CD4 cells. For a subset, Th1 and Th2 cytokines were assayed in plasma. Kruskal-Wallis tests were used to compare medians with tobit regression for censoring. Results: In the pilot cohort, we found that PLHIV with history of active pulmonary TB (n=20) had higher intact provirus than PLHIV without history of active TB (n=47) (794 vs 117 copies per million CD4, respectively; p<0.0001). In the confirmatory cohort, the quantity of intact provirus was higher in the TB group (n=13) compared with the non-TB group (n=18) (median 102 vs. 0 intact provirus per million CD4, respectively p=0.03). Additionally, we found that the frequencies of CD4+ T cells with any detectable proviral fragment was directly proportional to the levels of IL1B (p= 0.0025) and IL2 (p=0.0002). Conclusions: This is the first assessment of HIV provirus using IPDA in a clinical cohort from a resource limited setting, and the finding of larger reservoir in PLHIV with history of TB has significant implications for our understanding of TB-HIV coinfection and HIV cure efforts in TB-endemic settings.

2.
Surgery ; 168(1): 17-24, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32204923

RESUMEN

BACKGROUND: Posthepatectomy decompensation remains a frequent and poor outcome after hepatectomy, but its prediction is still inaccurate. Liver stiffness measurement can predict posthepatectomy decompensation, but there is a so-called "gray zone" that requires another predictor. Because splenomegaly is an objective sign of portal hypertension, we hypothesized that spleen volumetry could improve the identification of patients at risk. METHODS: Patients with hepatocellular carcinoma who underwent hepatectomy in our tertiary center between August 2014 and December 2017 were reviewed. The primary endpoint was to determine if the spleen volumetry and liver stiffness measurement were independent predictors of posthepatectomy decompensation, and secondarily, to determine if they were synergistic through a theoretic predictive model. RESULTS: One hundred and seven patients were included. The median follow-up time was 3 months (3-5). Postoperative 90-day mortality was 4.7%. By multivariate analysis, liver stiffness measurement and spleen volumetry predicted posthepatectomy decompensation. The liver stiffness measurement had a cutoff point of 11.6 kPa (area under receiver operating curve = 0.71 confidence interval 95% 0.71-0.88, sensitivity: 89%, specificity: 47%). The spleen volumetry cutoff point was 381.1 cm3 (area under receiver operating curve = 0.78, 95% confidence interval 0.77-0.93, sensitivity: 55%, specificity: 91%). The spleen volumetry improved prediction of posthepatectomy decompensation, because use of the spleen volumetry increased sensitivity (from 62% to 97%) and the negative predictive value (from 96% to 100%) along with a negligible decrease in specificity (from 96.7 to 93.4) and positive predictive value (from 64% to 59%) (P = .003). CONCLUSION: Spleen volumetry (>380 cm3) and liver stiffness measurement (>12 kPa) are non-invasive, independent, and synergistic tools that appear to be able to predict posthepatectomy decompensation. The importance of this finding is that these measurements may help to anticipate posthepatectomy decompensation and may possibly be used to direct alternative treatments to resection.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Hepatectomía , Hígado/diagnóstico por imagen , Complicaciones Posoperatorias/diagnóstico por imagen , Bazo/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/cirugía , Femenino , Humanos , Hígado/patología , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Estudios Retrospectivos
3.
Pharmaceuticals (Basel) ; 12(4)2019 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-31744203

RESUMEN

Fourteen arylsemicarbazone derivatives were synthesized and evaluated in order to find agents with potential anticancer activity. Cytotoxic screening was performed against K562, HL-60, MOLT-4, HEp-2, NCI-H292, HT-29 and MCF-7 tumor cell lines. Compounds 3c and 4a were active against the tested cancer cell lines, being more cytotoxic for the HL-60 cell line with IC50 values of 13.08 µM and 11.38 µM, respectively. Regarding the protein kinase inhibition assay, 3c inhibited seven different kinases and 4a strongly inhibited the CK1δ/ε kinase. The studied kinases are involved in several cellular functions such as proliferation, migration, cell death and cell cycle progression. Additional analysis by flow cytometry revealed that 3c and 4a caused depolarization of the mitochondrial membrane, suggesting apoptosis mediated by the intrinsic pathway. Compound 3c induced arrest in G1 phase of the cell cycle on HL-60 cells, and in the annexin V assay approximately 50% of cells were in apoptosis at the highest concentration tested (26 µM). Compound 4a inhibited cell cycle by accumulation of abnormal postmitotic cells at G1 phase and induced DNA fragmentation at the highest concentration (22 µM).

4.
Curr Top Med Chem ; 19(13): 1075-1091, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31223089

RESUMEN

BACKGROUND: Considering the need for the development of new antitumor drugs, associated with the great antitumor potential of thiophene and thiosemicarbazonic derivatives, in this work we promote molecular hybridization approach to synthesize new compounds with increased anticancer activity. OBJECTIVE: Investigate the antitumor activity and their likely mechanisms of action of a series of N-substituted 2-(5-nitro-thiophene)-thiosemicarbazone derivatives. METHODS: Methods were performed in vitro (cytotoxicity, cell cycle progression, morphological analysis, mitochondrial membrane potential evaluation and topoisomerase assay), spectroscopic (DNA interaction studies), and in silico studies (docking and molecular modelling). RESULTS: Most of the compounds presented significant inhibitory activity; the NCIH-292 cell line was the most resistant, and the HL-60 cell line was the most sensitive. The most promising compound was LNN-05 with IC50 values ranging from 0.5 to 1.9 µg.mL-1. The in vitro studies revealed that LNN-05 was able to depolarize (dose-dependently) the mitochondrial membrane, induceG1 phase cell cycle arrest noticeably, promote morphological cell changes associated with apoptosis in chronic human myelocytic leukaemia (K-562) cells, and presented no topoisomerase II inhibition. Spectroscopic UV-vis and molecular fluorescence studies showed that LNN compounds interact with ctDNA forming supramolecular complexes. Intercalation between nitrogenous bases was revealed through KI quenching and competitive ethidium bromide assays. Docking and Molecular Dynamics suggested that 5-nitro-thiophene-thiosemicarbazone compounds interact against the larger DNA groove, and corroborating the spectroscopic results, may assume an intercalating interaction mode. CONCLUSION: Our findings highlight 5-nitro-thiophene-thiosemicarbazone derivatives, especially LNN-05, as a promising new class of compounds for further studies to provide new anticancer therapies.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , ADN de Neoplasias/efectos de los fármacos , Nitrocompuestos/farmacología , Tiofenos/farmacología , Tiosemicarbazonas/farmacología , Inhibidores de Topoisomerasa II/farmacología , Adulto , Antineoplásicos/síntesis química , Antineoplásicos/química , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , ADN-Topoisomerasas de Tipo II/metabolismo , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Nitrocompuestos/síntesis química , Nitrocompuestos/química , Relación Estructura-Actividad , Tiofenos/síntesis química , Tiofenos/química , Tiosemicarbazonas/síntesis química , Tiosemicarbazonas/química , Inhibidores de Topoisomerasa II/síntesis química , Inhibidores de Topoisomerasa II/química , Células Tumorales Cultivadas
5.
Sci Rep ; 7(1): 10767, 2017 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-28883399

RESUMEN

Mycobacterium tuberculosis, the cause of Tuberculosis (TB), infects one third of the world's population and causes substantial mortality worldwide. In its shortest format, treatment of TB requires six months of multidrug therapy with a mixture of broad spectrum and mycobacterial specific antibiotics, and treatment of multidrug resistant TB is longer. The widespread use of this regimen makes this one of the largest exposures of humans to antimicrobials, yet the effects of TB treatment on intestinal microbiome composition and long-term stability are unknown. We compared the microbiome composition, assessed by both 16S rDNA and metagenomic DNA sequencing, of TB cases during antimycobacterial treatment and following cure by 6 months of antibiotics. TB treatment does not perturb overall diversity, but nonetheless dramatically depletes multiple immunologically significant commensal bacteria. The microbiomic perturbation of TB therapy can persist for at least 1.2 years, indicating that the effects of TB treatment are long lasting. These results demonstrate that TB treatment has dramatic effects on the intestinal microbiome and highlight unexpected durable consequences of treatment for the world's most common infection on human ecology.


Asunto(s)
Antituberculosos/efectos adversos , Disbiosis/etiología , Microbioma Gastrointestinal/efectos de los fármacos , Tuberculosis Pulmonar/tratamiento farmacológico , Adolescente , Adulto , Antituberculosos/uso terapéutico , Estudios Transversales , Quimioterapia Combinada , Femenino , Microbioma Gastrointestinal/genética , Haití , Humanos , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/efectos de los fármacos
6.
J Antimicrob Chemother ; 69(8): 2187-90, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24695352

RESUMEN

OBJECTIVES: Efavirenz is widely prescribed for HIV-1 infection. Three polymorphisms in CYP2B6 define plasma efavirenz trough concentration strata that vary across an ∼10-fold range. We characterized associations between human genetic polymorphisms and virologic response among participants who received efavirenz-containing regimens in a prospective clinical trial. METHODS: We genotyped 76 polymorphisms in CYP2B6 (including those that define efavirenz concentration strata), CYP2A6, CYP3A4, CYP3A5 and ABCB1 and week 48 virologic responses in 360 Haitians who initiated efavirenz-containing regimens in protocol HT 001. Associations were characterized by logistic regression analysis and Fisher's exact test. RESULTS: Proportions with HIV-1 RNA <50 or <200 copies/mL did not differ across 10 CYP2B6 metabolizer strata. In analyses that combined strata into three metabolizer levels (extensive, intermediate and slow), the respective proportions were 0.79, 0.79 and 0.81 (<50 copies/mL cut-off) and 0.84, 0.86 and 0.87 (<200 copies/mL cut-off). Genetic associations were not identified after controlling for baseline variables or with other polymorphisms after adjusting for multiple comparisons. CONCLUSIONS: Virologic failures in HT 001 were not explained by genetic polymorphisms known to define the lowest plasma efavirenz concentration stratum.


Asunto(s)
Benzoxazinas/sangre , Benzoxazinas/uso terapéutico , Citocromo P-450 CYP2B6/genética , Infecciones por VIH/tratamiento farmacológico , VIH-1/efectos de los fármacos , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Adulto , Alquinos , Fármacos Anti-VIH/uso terapéutico , Ciclopropanos , Citocromo P-450 CYP2A6/genética , Inductores del Citocromo P-450 CYP2B6/uso terapéutico , Citocromo P-450 CYP3A/genética , Femenino , Estudios de Asociación Genética , Haití , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Estudios Prospectivos , ARN Viral/sangre , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Metabolismo Secundario , Resultado del Tratamiento
7.
Am J Trop Med Hyg ; 89(4): 671-681, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24106194

RESUMEN

Successful and sustained efforts have been made to curtail the major cholera epidemic that occurred in Haiti in 2010 with the promotion of hygiene and sanitation measures, training of health personnel and establishment of treatment centers nationwide. Oral cholera vaccine (OCV) was introduced by the Haitian Ministry of Health as a pilot project in urban and rural areas. This paper reports the successful OCV pilot project led by GHESKIO Centers in the urban slums of Port-au-Prince where 52,357 persons received dose 1 and 90.8% received dose 2; estimated coverage of the at-risk community was 75%. This pilot study demonstrated the effort, community mobilization, and organizational capacity necessary to achieve these results in a challenging setting. The OCV intervention paved the way for the recent launching of a national cholera vaccination program integrated in a long-term ambitious and comprehensive plan to address Haiti's critical need in water security and sanitation.


Asunto(s)
Vacunas contra el Cólera/inmunología , Cólera/prevención & control , Vacunación , Administración Oral , Adolescente , Niño , Preescolar , Cólera/epidemiología , Vacunas contra el Cólera/administración & dosificación , Diarrea/epidemiología , Femenino , Haití/epidemiología , Humanos , Lactante , Masculino , Factores de Tiempo , Población Urbana
8.
PLoS Med ; 8(9): e1001095, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21949643

RESUMEN

BACKGROUND: In a randomized clinical trial of early versus standard antiretroviral therapy (ART) in HIV-infected adults with a CD4 cell count between 200 and 350 cells/mm³ in Haiti, early ART decreased mortality by 75%. We assessed the cost-effectiveness of early versus standard ART in this trial. METHODS AND FINDINGS: Trial data included use of ART and other medications, laboratory tests, outpatient visits, radiographic studies, procedures, and hospital services. Medication, laboratory, radiograph, labor, and overhead costs were from the study clinic, and hospital and procedure costs were from local providers. We evaluated cost per year of life saved (YLS), including patient and caregiver costs, with a median of 21 months and maximum of 36 months of follow-up, and with costs and life expectancy discounted at 3% per annum. Between 2005 and 2008, 816 participants were enrolled and followed for a median of 21 months. Mean total costs per patient during the trial were US$1,381 for early ART and US$1,033 for standard ART. After excluding research-related laboratory tests without clinical benefit, costs were US$1,158 (early ART) and US$979 (standard ART). Early ART patients had higher mean costs for ART (US$398 versus US$81) but lower costs for non-ART medications, CD4 cell counts, clinically indicated tests, and radiographs (US$275 versus US$384). The cost-effectiveness ratio after a maximum of 3 years for early versus standard ART was US$3,975/YLS (95% CI US$2,129/YLS-US$9,979/YLS) including research-related tests, and US$2,050/YLS excluding research-related tests (95% CI US$722/YLS-US$5,537/YLS). CONCLUSIONS: Initiating ART in HIV-infected adults with a CD4 cell count between 200 and 350 cells/mm³ in Haiti, consistent with World Health Organization advice, was cost-effective (US$/YLS <3 times gross domestic product per capita) after a maximum of 3 years, after excluding research-related laboratory tests. TRIAL REGISTRATION: ClinicalTrials.gov NCT00120510.


Asunto(s)
Antirretrovirales/economía , Atención a la Salud/economía , Infecciones por VIH/tratamiento farmacológico , Costos de la Atención en Salud , Nivel de Atención/economía , Adulto , Antirretrovirales/administración & dosificación , Antirretrovirales/efectos adversos , Recuento de Linfocito CD4 , Análisis Costo-Beneficio , Atención a la Salud/normas , Esquema de Medicación , Femenino , Guías como Asunto , Infecciones por VIH/economía , Haití , Humanos , Esperanza de Vida , Masculino
9.
N Engl J Med ; 363(3): 257-65, 2010 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-20647201

RESUMEN

BACKGROUND: For adults with human immunodeficiency virus (HIV) infection who have CD4+ T-cell counts that are greater than 200 and less than 350 per cubic millimeter and who live in areas with limited resources, the optimal time to initiate antiretroviral therapy remains uncertain. METHODS: We conducted a randomized, open-label trial of early initiation of antiretroviral therapy, as compared with the standard timing for initiation of therapy, among HIV-infected adults in Haiti who had a confirmed CD4+ T-cell count that was greater than 200 and less than 350 per cubic millimeter at baseline and no history of an acquired immunodeficiency syndrome (AIDS) illness. The primary study end point was survival. The early-treatment group began taking zidovudine, lamivudine, and efavirenz therapy within 2 weeks after enrollment. The standard-treatment group started the same regimen of antiretroviral therapy when their CD4+ T-cell count fell to 200 per cubic millimeter or less or when clinical AIDS developed. Participants in both groups underwent monthly follow-up assessments and received isoniazid and trimethoprim-sulfamethoxazole prophylaxis with nutritional support. RESULTS: Between 2005 and 2008, a total of 816 participants--408 per group--were enrolled and were followed for a median of 21 months. The CD4+ T-cell count at enrollment was approximately 280 per cubic millimeter in both groups. There were 23 deaths in the standard-treatment group, as compared with 6 in the early-treatment group (hazard ratio with standard treatment, 4.0; 95% confidence interval [CI], 1.6 to 9.8; P=0.001). There were 36 incident cases of tuberculosis in the standard-treatment group, as compared with 18 in the early-treatment group (hazard ratio, 2.0; 95% CI, 1.2 to 3.6; P=0.01). CONCLUSIONS: Early initiation of antiretroviral therapy decreased the rates of death and incident tuberculosis. Access to antiretroviral therapy should be expanded to include all HIV-infected adults who have CD4+ T-cell counts of less than 350 per cubic millimeter, including those who live in areas with limited resources. (ClinicalTrials.gov number, NCT00120510.)


Asunto(s)
Antirretrovirales/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Adulto , Antirretrovirales/efectos adversos , Antituberculosos/uso terapéutico , Recuento de Linfocito CD4 , Esquema de Medicación , Femenino , Estudios de Seguimiento , Infecciones por VIH/mortalidad , Haití , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/prevención & control
10.
Eur J Hum Genet ; 18(10): 1100-6, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20512159

RESUMEN

Warburg Micro Syndrome is a rare, autosomal recessive syndrome characterized by microcephaly, microphthalmia, microcornia, congenital cataracts, optic atrophy, cortical dysplasia, in particular corpus callosum hypoplasia, severe mental retardation, spastic diplegia, and hypogonadism. We have found five new mutations in the RAB3GAP1 gene in seven patients with suspected Micro Syndrome from families with Turkish, Palestinian, Danish, and Guatemalan backgrounds. A thorough clinical investigation of the patients has allowed the delineation of symptoms that are consistently present in the patients and may aid the differential diagnosis of Micro Syndrome for patients in the future. All patients had postnatal microcephaly, micropthalmia, microcornia, bilateral congenital cataracts, short palpebral fissures, optic atrophy, severe mental retardation, and congenital hypotonia with subsequent spasticity. Only one patient had microcephaly at birth, highlighting the fact that congenital microcephaly is not a consistent feature of Micro syndrome. Analysis of the brain magnetic resonance imagings (MRIs) revealed a consistent pattern of polymicrogyria in the frontal and parietal lobes, wide sylvian fissures, a thin hypoplastic corpus callosum, and increased subdural spaces. All patients were homozygous for the mutations detected and all mutations were predicted to result in a truncated RAB3GAP1 protein. The analysis of nine polymorphic markers flanking the RAB3GAP1 gene showed that the mutation c.1410C>A (p.Tyr470X), for which a Danish patient was homozygous, occurred on a haplotype that is shared by the unrelated heterozygous parents of the patient. This suggests a possible founder effect for this mutation in the Danish population.


Asunto(s)
Encéfalo/patología , Mutación , Proteínas de Unión al GTP rab3/genética , Anomalías Múltiples/genética , Anomalías Múltiples/patología , Árabes , Encéfalo/anomalías , Encéfalo/fisiopatología , Catarata/congénito , Catarata/genética , Catarata/patología , Cromosomas Humanos Par 2/genética , Córnea/anomalías , Córnea/patología , Dinamarca , Efecto Fundador , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Guatemala , Humanos , Hipogonadismo/genética , Hipogonadismo/patología , Discapacidad Intelectual/genética , Discapacidad Intelectual/patología , Imagen por Resonancia Magnética , Microcefalia/genética , Microcefalia/patología , Atrofia Óptica/genética , Atrofia Óptica/patología , Turquía
11.
Salud Publica Mex ; 51 Suppl 1: S25-37, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19287890

RESUMEN

Quantitative ultrasound (QUS) appears to be developing into an acceptable, low-cost and readily-accessible alternative to dual X-ray absorptiometry (DXA) measurements of bone mineral density (BMD) in the detection and management of osteoporosis. Perhaps the major difficulty with their widespread use is that many different QUS devices exist that differ substantially from each other, in terms of the parameters they measure and the strength of empirical evidence supporting their use. But another problem is that virtually no data exist outside of Caucasian or Asian populations. In general, heel QUS appears to be most tested and most effective. Some, but not all heel QUS devices are effective assessing fracture risk in some, but not all populations, the evidence being strongest for Caucasian females > 55 years old, though some evidence exists for Asian females > 55 and for Caucasian and Asian males > 70. Certain devices may allow to estimate the likelihood of osteoporosis, but very limited evidence exists supporting QUS use during the initiation or monitoring of osteoporosis treatment. Likely, QUS is most effective when combined with an assessment of clinical risk factors (CRF); with DXA reserved for individuals who are not identified as either high or low risk using QUS and CRF. However, monitoring and maintenance of test and instrument accuracy, precision and reproducibility are essential if QUS devices are to be used in clinical practice; and further scientific research in non-Caucasian, non-Asian populations clearly is compulsory to validate this tool for more widespread use.


Asunto(s)
Densidad Ósea , Osteoporosis/diagnóstico por imagen , Algoritmos , Pueblo Asiatico , Calcáneo/diagnóstico por imagen , Densitometría/economía , Densitometría/instrumentación , Femenino , Fracturas Espontáneas/etiología , Humanos , Masculino , Osteoporosis/etnología , Osteoporosis/terapia , Medición de Riesgo/métodos , Ultrasonografía/instrumentación , Población Blanca
12.
Salud pública Méx ; 51(supl.1): s25-s37, 2009. ilus, tab
Artículo en Inglés | LILACS | ID: lil-508402

RESUMEN

Quantitative ultrasound (QUS) appears to be developing into an acceptable, low-cost and readily-accessible alternative to dual X-ray absorptiometry (DXA) measurements of bone mineral density (BMD) in the detection and management of osteoporosis. Perhaps the major difficulty with their widespread use is that many different QUS devices exist that differ substantially from each other, in terms of the parameters they measure and the strength of empirical evidence supporting their use. But another problem is that virtually no data exist outside of Caucasian or Asian populations. In general, heel QUS appears to be most tested and most effective. Some, but not all heel QUS devices are effective assessing fracture risk in some, but not all populations, the evidence being strongest for Caucasian females > 55 years old, though some evidence exists for Asian females > 55 and for Caucasian and Asian males > 70. Certain devices may allow to estimate the likelihood of osteoporosis, but very limited evidence exists supporting QUS use during the initiation or monitoring of osteoporosis treatment. Likely, QUS is most effective when combined with an assessment of clinical risk factors (CRF); with DXA reserved for individuals who are not identified as either high or low risk using QUS and CRF. However, monitoring and maintenance of test and instrument accuracy, precision and reproducibility are essential if QUS devices are to be used in clinical practice; and further scientific research in non-Caucasian, non-Asian populations clearly is compulsory to validate this tool for more widespread use.


El ultrasonido cuantitativo (QUS) es una alternativa para la detección y manejo de la osteoporosis de bajo costo y uso práctico, si se compara con las densitometrías de rayos X de doble haz de baja energía (DXA) que determinan densidad mineral ósea (BMD). La mayor dificultad para el uso generalizado del QUS por un lado es que existen muchos instrumentos que son significativamente diferentes uno del otro y por otro en la calidad de la evidencia en que se justifica su empleo, que generalmente es insuficiente y/o poco sistematizada. Otro problema importante del QUS, es que prácticamente no existe información que no sea la generada en poblaciones asiáticas o caucásicas. En general, los estudios de calcáneo realizados con QUS son los más utilizados y mejor validados para evaluar el riesgo de fracturas en algunas poblaciones. La evidencia más grande de su efectividad se conoce para las mujeres caucásicas y asiáticas mayores de 55 años e incluso para los hombres asiáticos mayores de 70 años. Varios instrumentos cuentan con buen sustento científico, que los vuelve confiables para establecer un pronóstico preciso e identificar el riesgo individual de sufrir fracturas por osteoporosis, sin embargo, existe poca evidencia que respalde su uso para iniciar y monitorear el resultado del tratamiento de la osteoporosis. El QUS mejora su efectividad diagnóstica cuando se combina con los resultados de un cuestionario que identifica riesgos clínicos. En un escenario ideal, el DXA se debe reservar solo para aquellos individuos que no puedan ser identificados de manera confiable usando QUS y el cuestionario de riesgos clínicos. Si se quiere aceptar a los instrumentos QUS en la práctica clínica, para el monitoreo es indispensable asegurar y mantener la exactitud, precisión y reproducibilidad de los instrumentos y de los técnicos que los utilizan. Se requieren más estudios científicos de poblaciones no caucásicas o asiáticas para validar el uso generalizado del QUS.


Asunto(s)
Femenino , Humanos , Masculino , Densidad Ósea , Osteoporosis , Algoritmos , Pueblo Asiatico , Calcáneo , Densitometría/economía , Densitometría/instrumentación , Población Blanca , Fracturas Espontáneas/etiología , Osteoporosis/etnología , Osteoporosis/terapia , Medición de Riesgo/métodos , Ultrasonografía/instrumentación
13.
Rev. chil. neuro-psiquiatr ; Rev. chil. neuro-psiquiatr;31(3): 285-91, jul.-sept. 1993. tab, ilus
Artículo en Español | LILACS | ID: lil-131614

RESUMEN

Se evaluaron 19 pacientes esquizofrénicos, 17 con depresión mayor y 11 controles psiquiátricos con el test de estimulación con TRH, la prueba de supresión por dexametasona (PSD) y el test de estimulación con LHRH. Todos los pacientes cumplieron con criterios estrictos para considerar válidos los test y estuvieron sin medicación a lo menos durante 10 días. No se observaron diferencias significativas para la respuesta a LHRH ni al TRH entre los grupos. Sólo los resultados de la PSD difirieron significativamente en los depresivos (p<0,05). Noventa y cuatro por ciento de los depresivos tuvieron al menos una respuesta hormonalanormal, este porcentaje fue significativamentemayor que en los esquizofrénicos y controles (p<0,05). El test anormal más frecuente fue una respuesta exagerada a LHRH, pero no se encontraron diferencias entre los grupos. No se encontraron correlaciones significativas entre las respuestas anormales al TRH o en la PSD y la hormona folículo estimulante (FSH) o la hormona luteinizante (LH). En este estudio sólo el eje hipotálamo-hipófisis-adrenal evidencia una diferencia entre los grupos diagnósticos. Las anormalidades neuroendocrinas se observaron con mayor frecuencia entre los pacientes depresivos. Este trabajo muestra la existencia de disregulaciones neuroendocrinas, pero no sugiere especificidad diagnóstica o interdependencia entre los ejes


Asunto(s)
Humanos , Masculino , Adolescente , Adulto , Depresión/fisiopatología , Hormonas Esteroides Gonadales/fisiología , Sistemas Neurosecretores/fisiopatología , Esquizofrenia/fisiopatología , Dexametasona/administración & dosificación , Estradiol/metabolismo , Hidrocortisona/metabolismo , Sistemas Neurosecretores/efectos de los fármacos , Testosterona/metabolismo
14.
Rev. chil. neuro-psiquiatr ; Rev. chil. neuro-psiquiatr;27(2): 111-22, abr.-jun. 1989. tab, ilus
Artículo en Español | LILACS | ID: lil-87421

RESUMEN

En este trabajo se describe el protocolo de exploración clínico-biológico (o PEBC) el que complementa al enfoque clínico y psicométrico en el estudio del paciente psiquiátrico. Este protocolo se realiza luego de un período libre de drogas, de al menos diez días y evalúa (1) el eje neuroclínico: estudio de las monoaminas y sus catabolitos en LCR y en orina de 24 horas (2) el eje neuroendocrino: estudio de la respuesta hormonal al test a la dexametasona, el test a la TRH, el test a la clonidina; el test a la apomorfina y el test a la fenfluramia (3) el eje crono biológico: estudio de los ritmos circadianos del cortisol, de ACTH, de TSH, de PRL, de GH y de melatonina. La utilización conjunta de técnicas de los tres ejes pretende establecer una correlación entre las alteraciones biológicas y los síndromes clínicos. Del mismo modo se busca estudiar los mecanismos de ección de sustancias psicotrópicas y evaluar la duración necesaria de un tratamiento


Asunto(s)
Humanos , Disciplina de Cronobiología , Trastornos Mentales/fisiopatología , Neurobiología , Neuroendocrinología , Protocolos Clínicos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA