RESUMEN
BACKGROUND: Lymphogranuloma venereum (LGV) is a sexual transmitted infection (STI), currently endemic within the population of men who have sex with men (MSM) of Western Countries. L2B variant has been reported as the predominant strain in the current LGV epidemics, although a shift towards L2-434 has been observed in some European countries. OBJECTIVES: To evaluate and characterize the population with LGV infection diagnosed in Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal. METHODS: A retrospective analysis of all LGV diagnoses between 2016 and 2019 was performed. The diagnosis was established through ompA-genotyping of samples yielding a positive result to Chlamydia trachomatis (CT). All considered samples were retrieved from the clinician activity, through swabbing and urine analysis and CT infection diagnosis was obtained using real-time PCR. RESULTS: During the period studied 16 279 CT diagnostics tests were employed, with a striking increase from 2016 (n = 467) to 2019 (n = 9362). A total of 1602 diagnoses of CT were established, from which 168 (10.5%) corresponded to LGV, with both infections showing a rising evolution, between 2016 and 2019, of 2.9 and 2.7 times, respectively. The majority of the LGV strains were genotyped as L2/434 (67.3%; n = 113). LGV predominantly affected MSM and men who have sex with men and women (97.0%; n = 163). Anorectal infection was the most prevalent one (90.5%; n = 152), being proctitis the main clinical presentation (76.2%; n = 128). Absence of symptoms was reported in almost 15% of the cases (n = 24). The presence of concomitant infection with human immunodeficiency virus was dominant (73.2%; n = 123) and the prevalence of one or more STI co-infections was about 60.1% (n = 99). CONCLUSIONS: An increasing evolution of CT and LGV testing and diagnosing was observable throughout the studied period. Characteristics of the population are similar with those described within LGV epidemics. In accordance with recent European studies, predominance towards L2 genotype was identified.
Asunto(s)
Linfogranuloma Venéreo , Minorías Sexuales y de Género , Chlamydia trachomatis/genética , Europa (Continente) , Femenino , Homosexualidad Masculina , Humanos , Linfogranuloma Venéreo/diagnóstico , Linfogranuloma Venéreo/epidemiología , Masculino , Portugal , Estudios RetrospectivosRESUMEN
This study presents the serotype distribution and the antibiotic resistance profile of 953 colonising group B Streptococcus (GBS) recovered from women of child bearing age (15 to 49 years) between 2005 and 2012 in the Lisbon and Tagus Valley region, Portugal. Overall, serotypes Ia, II, III, and V were the most common, accounting 752 of the 953 isolates (about 80%). However, there were changes in GBS distribution, in particular in the two last years of the study. Of note, the proportion of serotype IV isolates increased from 1% (2/148) in 2006 to 20% (19/97) in 2012. Also, considerable proportions of serotype IV isolates from 2010 to 2012 were respectively resistant to erythromycin (9/43; 21%) or clindamycin (6/43; 14%). The identification of nine serotype IV isolates presenting a novel association with the clonal complex (CC) 17 lineage, involving a putative capsular switch, may accentuate their virulence potential and ecological success. Molecular analysis of this subgroup of isolates revealed the presence of rib, IS (insertion sequence) 861 and GBSi1 group II intron within the C5a peptidase gene (scpB) laminin-binding protein gene (lmb) region, reflecting high clonality and a putative common origin. A close surveillance of the emergent type IV/CC17 isolates is crucial considering the potential impact over GBS treatment guidelines and capsular vaccine development.
Asunto(s)
Farmacorresistencia Microbiana/genética , Infecciones Estreptocócicas/epidemiología , Streptococcus agalactiae/clasificación , Streptococcus agalactiae/aislamiento & purificación , Adolescente , Adulto , Antígenos Bacterianos/genética , Niño , Clindamicina/administración & dosificación , ADN Bacteriano/genética , Eritromicina/administración & dosificación , Femenino , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Epidemiología Molecular , Vigilancia de la Población , Portugal/epidemiología , Análisis de Secuencia de ADN , Serotipificación , Infecciones Estreptocócicas/tratamiento farmacológico , Infecciones Estreptocócicas/microbiología , Streptococcus agalactiae/efectos de los fármacos , Streptococcus agalactiae/genética , Adulto JovenRESUMEN
Streptococcus agalactiae, group B streptococci (GBS) is the leading cause of severe bacterial infections in newborns. GBS expression studies allowed the identification and characterization of virulence factors and a better understanding of the host-pathogen-environment interactions. The measurement of transcript levels by quantitative real-time PCR (qRT-PCR) is a widely used technique in GBS; however, a systematic evaluation and validation of reference gene stability for normalization purposes in GBS expression studies is currently lacking. Therefore, we analyzed the stability of 10 candidate reference genes (16SrRNA, glcK, glnA, groEL, gyrA, recA, rpoB, rpsL, sdhA and tkt) in three GBS prototype strains (O90R, NEM316 and 2603V/R) grown at different temperature conditions (37°C and 40°C). Our approach was based on the calibration of transcript levels from each gene against the number of bacteria from the same sample (ratio messenger RNA/genomic DNA). As a complementary analysis, reference gene stability was also investigated through the bioinformatic applications, geNorm and NormFinder. Considering the whole GBS development cycle, only a minority of genes were stable under both growth conditions, but this number increased when restricting the analysis to the logarithmic time-points. The range of stable genes was higher at 37°C, where recA and sdhA were stable simultaneously for the three strains, and six out of 10 genes were stable for at least two strains. At 40°C, recA showed up again as one of the best options, suggesting its potential use as reference gene in future qRT-PCR studies. The results generated with geNorm and NormFinder were consistent with those obtained experimentally and evidenced minor variations either among strains or temperature conditions. In conclusion, the fluctuation of expression of reference genes observed among different GBS strains and growth conditions highlights the importance of carefully validating, for each experimental scenario, the use of reference genes for qRT-PCR normalization purposes. Nevertheless, recA seems to be a good candidate for such optimizations.
Asunto(s)
Genes Bacterianos , Reacción en Cadena en Tiempo Real de la Polimerasa/normas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/normas , Streptococcus agalactiae/genética , Transcriptoma , Calibración , Expresión Génica , Regulación Bacteriana de la Expresión Génica , ARN Bacteriano/genética , ARN Bacteriano/aislamiento & purificación , Estándares de Referencia , Reproducibilidad de los Resultados , Streptococcus agalactiae/crecimiento & desarrolloRESUMEN
The aim of this study was to perform a retrospective evaluation of the success of patient referral for partner notification of chlamydial infections to the major Portuguese sexually transmitted infection (STI) clinic. A total of 8277 patients were screened for Chlamydia trachomatis during 2000-2007, and 695 (8.4%) tested positive. The sexual partners of 34% of these index cases attended the clinic as contacts following partner referral. In univariate analysis, heterosexual men referred partners more frequently than men who have sex with men (MSM) and HIV-negative index cases referred partners four-fold more frequently than HIV-positives; however, these associations were non-significant after multivariate analysis (adjusted odds ratio [OR] 1.4, 95% confidence interval [CI] 0.7-2.6; adjusted OR 4.2, 95% CI 0.9-18.7, respectively). Index patients who reported lower numbers of partners referred more frequently, and this association remained significant after multivariate analysis. One-third of the referred individuals tested C. trachomatis-positive; the risk for infection was three-fold higher for referred partners from symptomatic index cases (P < 0.001, adjusted OR, 95% CI 1.8-6.3). In conclusion, the results of the present study concerning sexual behaviour, HIV status and clinical signs highlight the need for further evaluations that may shape future partner notification strategies in order to reduce the chlamydial disease burden.
Asunto(s)
Instituciones de Atención Ambulatoria/estadística & datos numéricos , Infecciones por Chlamydia/diagnóstico , Chlamydia trachomatis , Trazado de Contacto/estadística & datos numéricos , Evaluación de Programas y Proyectos de Salud , Derivación y Consulta/estadística & datos numéricos , Adolescente , Adulto , Anciano , Infecciones por Chlamydia/epidemiología , Infecciones por Chlamydia/prevención & control , Femenino , Humanos , Masculino , Tamizaje Masivo/métodos , Persona de Mediana Edad , Portugal/epidemiología , Conducta Sexual , Parejas Sexuales , Enfermedades de Transmisión Sexual/diagnóstico , Enfermedades de Transmisión Sexual/epidemiología , Enfermedades de Transmisión Sexual/prevención & control , Adulto JovenRESUMEN
OBJECTIVES: To determine the validity and reliability of the personalised nursing care index (PNCI). METHODS: A descriptive study was carried out in the Puerta del Mar Hospital (Cádiz) of the Andalusian Health Service, which included all patients admitted to an Internal Medicine ward from May 2007 to July 2008. A descriptive analysis was performed on the population included in the study. Furthermore, reliability was analysed with the 20-Kuder-Richardson coefficient and a correlation matrix between PNCI items; and validity via a maximum likelihood factorial analysis, and a ROC curve to determine sensitivity and specificity. RESULTS: A total of 219 people were included in the survey, of whom 74.4% were patients and 26.6% caregivers. The percentages of males and females were similar with a mean age of 62.5 years and 48.4% finished basic school education. The 20-Kuder-Richarson value was 0.835; and a positive correlation between items, which corresponded to 3 groups of items (factors). The maximum likelihood factorial analysis confirmed the 3 items-factor groups with a Promax rotation due to the high correlation between them. The maximum explained variance was 91.42%. The ROC curve area was 90.1% with a cut-off point of 8, for a sensitivity of 79.9% and a specificity of 90.6%. CONCLUSIONS: The PCNI is reliable, with the internal consistency coefficient value in between an optimum range. Furthermore, factors obtained from the matrix correlation inter-items were confirmed with a factorial analysis, resulting in a high explained variance. The curve ROC area is excellent compared to the gold standard, considered as the perception of confidence relationship.
Asunto(s)
Encuestas de Atención de la Salud , Atención de Enfermería , Personal de Enfermería en Hospital/estadística & datos numéricos , Satisfacción del Paciente/estadística & datos numéricos , Medicina de Precisión , Adulto , Anciano , Cuidadores/psicología , Estudios Transversales , Femenino , Unidades Hospitalarias , Hospitales Urbanos , Humanos , Medicina Interna , Masculino , Persona de Mediana Edad , Pacientes/psicología , Proyectos Piloto , Curva ROC , Reproducibilidad de los Resultados , España , Encuestas y CuestionariosRESUMEN
Chlamydia trachomatis is a widespread obligate intracellular pathogen genetically non-tractable for which transcriptomics is a fundamental tool to better understand its biology. However, the suitability of endogenous controls for normalization of transcriptomic data in this bacterium still needs validation. We aimed to assess the stability of 10 genes for their potential use as endogenous controls in real-time quantitative PCR assays at both normal and stress (D-cycloserine treatment) growth conditions throughout the developmental cycle of three C. trachomatis strains with different tissue tropism. Normalization was performed by real-time absolute quantification of the bacterial genomes. We also tested the applicability of two widely used softwares (geNorm and Normfinder) to our data. For all strains, we found that 16SrRNA was the most stably expressed gene throughout the chlamydial normal developmental cycle, which indicates its potential use as endogenous control in relative expression assays. However, it was highly unstable under D-cycloserine treatment (where oppA_2 was top-ranked), suggesting prudence when using ribosomal genes in expression experiments involving stress conditions. The geNorm and Normfinder algorithms revealed contrasting results and seem inappropriate for the selected pool of genes. Considering the multiplicity of experimental conditions, there should be an in loco validation of endogenous controls, where 16SrRNA appears to be in the front line. Alternatively, normalization of expression data against genomic DNA, which is less influenced by experimental constraints that are especially relevant for intracellular organisms, likely constitutes a good option. Moreover, the number of genomes also seems to be less subject to variation than expression of endogenous controls when working under stress conditions. The present study constitutes the first evaluation of putative endogenous controls for real-time expression assays in C. trachomatis.
Asunto(s)
Chlamydia trachomatis/genética , Perfilación de la Expresión Génica/normas , Reacción en Cadena de la Polimerasa/normas , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Chlamydia trachomatis/metabolismo , Perfilación de la Expresión Génica/métodos , Reacción en Cadena de la Polimerasa/métodos , Estándares de ReferenciaRESUMEN
Knowledge of the epidemiology of Streptococcus agalactiae in Portugal is limited: therefore, the present study aimed to investigate the carriage rate of S. agalactiae among Portuguese women of reproductive age and the prevalence of antibiotic resistance, as well as to perform a molecular characterization of the clinical isolates. S. agalactiae was recovered from 6.2% of 4269 women during the period 20052007, with a predominance of capsular genotypes III (35%), V (33%), Ia (16%) and II (10%) in a sample of 100 isolates. To our knowledge, this is the first report of the S. agalactiae colonization rate in Portugal determined according to CDC guidelines. All isolates were susceptible to penicillin and vancomycin, whereas resistance to clindamycin and erythromycin was detected in 10% and 19% of isolates, respectively. Among the 19 erythromycin-resistant isolates, ten (53%) displayed the constitutive MLS(B) phenotype (conferring high-level resistance to macrolides), eight (42%) had the inducible MLS(B), and the M phenotype accounted for one isolate (5%). erm methylase genes were exclusively associated with MLS(B) phenotype isolates, whereas the M phenotype was a result of the presence of mefA. Multilocus sequence typing analysis of the genetic relatedness among isolates presenting resistance to erythromycin demonstrated a novel association between erythromycin resistance and the subtype III-1/ST-19 genetic clone family.
Asunto(s)
Portador Sano/epidemiología , Farmacorresistencia Bacteriana , Eritromicina/farmacología , Infecciones Estreptocócicas/epidemiología , Streptococcus agalactiae/clasificación , Streptococcus agalactiae/efectos de los fármacos , Adolescente , Adulto , Antibacterianos/farmacología , Técnicas de Tipificación Bacteriana , Portador Sano/microbiología , Femenino , Genotipo , Humanos , Lincosamidas/farmacología , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Epidemiología Molecular , Tipificación Molecular , Portugal/epidemiología , Infecciones Estreptocócicas/microbiología , Streptococcus agalactiae/aislamiento & purificación , Estreptogramina B/farmacología , Adulto JovenRESUMEN
Lymphogranuloma venereum, caused by the L serovars of Chlamydia trachomatis, emerged in Europe in 2003 and a series of outbreaks were reported in different countries. The infection presents as a severe proctitis in men who have sex with men, many of whom are co-infected with HIV and other sexually transmitted infections. This paper reviews the number of cases reported over a five year period, from 2003 to 2008, from countries that were part of the European Surveillance of Sexually Transmitted Infections (ESSTI) network. Reports were received from Belgium, Denmark, France, Germany, the Netherlands, Portugal, Spain, Sweden, and the United Kingdom. It appears that after five years the characteristics of the patients infected has overall remained unchanged, although the total number of cases has increased and more countries in Europe have now identified cases of LGV.
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Brotes de Enfermedades/estadística & datos numéricos , Infecciones por VIH/epidemiología , Homosexualidad Masculina/estadística & datos numéricos , Linfogranuloma Venéreo/epidemiología , Adulto , Comorbilidad , Europa (Continente)/epidemiología , Humanos , Incidencia , Masculino , Vigilancia de la Población , Medición de Riesgo , Factores de RiesgoRESUMEN
A molecular system was used to subtype Portuguese Treponema pallidum clinical strains isolated from both skin lesions and blood. The study with this system constitutes the first typing study in a European country. Three T. pallidum subtypes were found: subtypes 14a (50%), 14d (45.2%), and 14f (4.8%). Further studies are needed to better characterize the isolates involved in syphilis outbreaks.
Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Epidemiología Molecular/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Sífilis/microbiología , Treponema pallidum/clasificación , Treponema pallidum/genética , Sangre/microbiología , Análisis por Conglomerados , Dermatoglifia del ADN/métodos , Femenino , Genotipo , Humanos , Masculino , Portugal/epidemiología , Piel/microbiología , Sífilis/epidemiología , Treponema pallidum/aislamiento & purificaciónRESUMEN
Two temporally and geographically clustered cases of meningitis caused by Streptococcus agalactiae expressing the infrequent Ib serotype are reported. Characterization by pulsed-field gel electrophoresis and multilocus sequence typing revealed that the isolates were identical and represented the widely distributed ST10/ST8 lineage associated with serotype Ib.
Asunto(s)
Meningitis Bacterianas/microbiología , Streptococcus agalactiae/clasificación , Anciano , Técnicas de Tipificación Bacteriana , Electroforesis en Gel de Campo Pulsado , Femenino , Humanos , Persona de Mediana Edad , Análisis de Secuencia de ADN , Serotipificación , Streptococcus agalactiae/genéticaRESUMEN
BACKGROUND: The consequences of atrial fibrillation (AF) on morbido-mortality of patients on hemodialysis have not been fully explored. The objective of this study was to determine the prevalence of AF in patients on hemodialysis and to evaluate its influence on the development of thromboembolic phenomena (TEP). METHODS: The incidence of AF in 190 patients in our hemodialysis program was assessed, and the patients were followed up for 1 year. Pertinent demographic and biochemical parameters were entered into univariate and multivariate statistical analyses to evaluate associations with overall mortality and TEP such as cerebrovascular accident, transitory ischemic accident, or peripheral embolism. RESULTS: In 13.6% of patients, AF was found; 9.4% of these were of the permanent type. In the multivariate analysis, only increased age was associated with a higher probability of having arrhythmia (odds ratio, 1.10; 95% confidence interval, 1.03-1.17; P =.003). During follow-up, 23% of the patients with AF died compared with 6% of those in sinus rhythm (P <.05), although AF did not appear to be an independent predictive factor for death. Thirty-five percent of the patients with AF and 4% with sinus rhythm had TEP (P <.01). In the multivariate analysis, AF was identified as the only independent predictor for TEP (odds ratio, 8; 95% CI, 2.3-27; P =.0008). CONCLUSIONS: AF is a frequent arrhythmia in patients on hemodialysis, and approximately 1 in 3 hemodialysis patients with AF had thromboembolic complications within 1 year of follow-up. These findings suggest that the consensus contraindication of prophylactic anticoagulation therapy for this group of patients may need to be redefined.
Asunto(s)
Fibrilación Atrial/epidemiología , Isquemia Encefálica/mortalidad , Diálisis Renal/mortalidad , Tromboembolia/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Anticoagulantes/uso terapéutico , Fibrilación Atrial/complicaciones , Fibrilación Atrial/prevención & control , Isquemia Encefálica/etiología , Isquemia Encefálica/prevención & control , Estudios Transversales , Femenino , Humanos , Incidencia , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Prevalencia , Pronóstico , Recurrencia , Diálisis Renal/efectos adversos , Factores de Riesgo , Tasa de Supervivencia , Tromboembolia/etiología , Tromboembolia/prevención & controlRESUMEN
The design, synthesis and alpha1-adrenoceptor antagonism of a series of bis-imidazoline (1a, 2a, 3a and 4a) and bis-guanidine (1b, 2b, 3b and 4b) diphenyl derivatives are reported. All of these compounds fulfill the conditions of the most recent pharmacophore proposed for alpha1-adrenoceptors and found in the literature. Besides, a novel synthetic approach to the preparation of 2-(arylimino)imidazolidine derivatives is described. All the tested compounds, except the bis-guanidinium derivative 3b, inhibit the contractile responses induced by noradrenaline in aortic rings of rat and rabbit in a dose-dependent manner. Our results indicate that, even though some discrepancies are observed in terms of the alpha1 subtype targeted by this new family of compounds, they show an interesting profile as antagonists of alpha1-adrenoceptors and a new prototype, compound 1a, has been found deserving further development.
Asunto(s)
Antagonistas Adrenérgicos alfa/síntesis química , Antagonistas Adrenérgicos alfa/farmacología , Imidazoles/química , Imidazoles/farmacología , Iminas/química , Iminas/farmacología , Antagonistas Adrenérgicos alfa/química , Animales , Aorta Torácica/química , Aorta Torácica/efectos de los fármacos , Aorta Torácica/fisiología , Bradiquinina/farmacología , Relación Dosis-Respuesta a Droga , Femenino , Guanidina/análogos & derivados , Guanidina/química , Guanidina/farmacología , Cobayas , Imidazoles/síntesis química , Iminas/síntesis química , Concentración 50 Inhibidora , Masculino , Modelos Moleculares , Contracción Muscular/efectos de los fármacos , Músculo Esquelético/química , Músculo Esquelético/efectos de los fármacos , Músculo Liso Vascular/fisiología , Norepinefrina/antagonistas & inhibidores , Norepinefrina/farmacología , Conejos , Ratas , Receptores Adrenérgicos alfa/metabolismo , Relación Estructura-Actividad , Vasoconstricción/efectos de los fármacos , Vasoconstrictores/antagonistas & inhibidores , Vasoconstrictores/farmacologíaAsunto(s)
Apoptosis/efectos de los fármacos , Calcitriol/farmacología , Rechazo de Injerto/inmunología , Trasplante de Riñón/inmunología , Linfocitos T/inmunología , Células Cultivadas , Diagnóstico Diferencial , Rechazo de Injerto/patología , Humanos , Trasplante de Riñón/fisiología , Linfocitos T/efectos de los fármacos , Linfocitos T/patologíaRESUMEN
Calcitriol is used to treat hyperparathyroidism in hemodialysis patients. Calcitriol treatment, either through a reduction in parathyroid hormone (PTH) levels or direct effect on bone, decreases the osteoblast and osteoclast surface and bone formation rate. Our study of 13 hemodialysis patients was designed to evaluate whether calcitriol treatment changed the rate of spontaneous recovery from hypocalcemia induced by a low-calcium dialysis. Calcitriol treatment decreased basal PTH levels from 614 +/- 84 to 327 +/- 102 pg/mL (P < 0.001) and maximal PTH levels from 1,282 +/- 157 to 789 +/- 161 pg/mL (P < 0.001), but the rate of serum ionized calcium recovery from hypocalcemia did not change. When the 13 patients were separated based on the median age of 64 years, the predialysis serum ionized calcium level was less in the younger (group I, 44 +/- 6 years; n = 6) than older (group II, 68 +/- 1 years; n = 7) patients (1.05 +/- 0.03 v 1.22 +/- 0.03 mmol/L, respectively; P < 0.01) despite similar basal (group I, 595 +/- 122 pg/mL v group II, 629 +/- 96 pg/mL) and maximal (group I, 1,114 +/- 299 pg/mL v group II, 1,425 +/- 141 pg/mL) PTH levels. Before calcitriol treatment, the rate of serum ionized calcium recovery from induced hypocalcemia was greater (P < 0.05) for similar PTH levels in the older than younger patients. After calcitriol treatment, despite a similar reduction in PTH levels, the rate of calcium recovery increased (P < 0.05) in the younger patients but did not change in the older patients. We also observed that toward the end of the low-calcium hemodialysis, PTH values decreased even though serum ionized calcium level continued to decline when the rate of calcium reduction slowed. In addition, hysteresis, defined as a lower PTH value during the recovery from hypocalcemia than during the induction of hypocalcemia for the same serum calcium concentration, was present during the spontaneous recovery from hypocalcemia. In conclusion, in the hemodialysis patient: (1) age appeared to affect the bone response to PTH and calcitriol treatment, (2) the PTH response to hypocalcemia was affected by a deceleration in the rate of calcium decrease, and (3) hysteresis of the PTH response to hypocalcemia occurred during the spontaneous recovery from hypocalcemia.
Asunto(s)
Calcitriol/administración & dosificación , Hipocalcemia/sangre , Fallo Renal Crónico/sangre , Diálisis Renal , Adulto , Factores de Edad , Anciano , Remodelación Ósea/efectos de los fármacos , Calcio/sangre , Femenino , Humanos , Hipocalcemia/tratamiento farmacológico , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Hormona Paratiroidea/sangreRESUMEN
BACKGROUND: Bolus calcitriol (CTR) is used for the treatment of secondary hyperparathyroidism in dialysis patients. Although CTR treatment reduces parathyroid hormone (PTH) levels in many dialysis patients, a significant number fail to respond. METHODS: To learn whether or not an analysis of parathyroid function could further illuminate the response to CTR, a PTH-calcium curve was performed before and after at least two months of CTR treatment in 50 hemodialysis patients with a predialysis intact PTH of greater than 300 pg/ml. RESULTS: For the entire group (N = 50), CTR treatment resulted in a 24% reduction in predialysis (basal) PTH from 773 +/- 54 to 583 +/- 71 pg/ml (P < 0.001), whereas ionized calcium increased from 1.10 +/- 0.02 to 1.22 +/- 0.02 mM (P < 0.001); however, maximal and minimal PTH did not change from pre-CTR values. Based on whether or not the basal PTH decreased by 40% or more during CTR treatment, patients were divided into responders (Rs, N = 25) and nonresponders (NRs, N = 25). Before CTR, the NR group was characterized by a greater basal (959 +/- 80 vs. 586 +/- 51 pg/ml, P < 0.001) and maximal (1899 +/- 170 vs. 1172 +/- 108 pg/ml, P < 0. 001) PTH and serum phosphorus (6.14 +/- 0.25 vs. 5.14 +/- 0.34 mg/dl, P < 0.01). Logistical regression analysis showed that the pre-CTR basal PTH was the most important predictor of the post-CTR basal PTH, and a pre-CTR basal PTH of 750 pg/ml represented a 50% probability of a response. Basal PTH correlated with the ionized calcium in the NR group (r = 0.59, P = 0.002) but not in the R group (r = 0.06, P = NS). In the R group, an inverse correlation was present between ionized calcium and the basal/maximal PTH ratio, an indicator of whether calcium is suppressing basal PTH secretion relative to the maximal secretory capacity (maximal PTH) r = -0.55, P = 0.004; in the NR group, this correlation approached significance but was positive (r = 0.34, P = 0.09). After CTR treatment, serum calcium increased in both groups, and despite marked differences in basal PTH (Rs, 197 +/- 25 vs. NRs, 969 +/- 85 pg/ml), an inverse correlation between ionized calcium and basal/maximal PTH was present in both groups (Rs, r = -0.61, P = 0.001, and NRs, r = -0.60, P = 0.001). CONCLUSIONS: (a) Dynamic testing of parathyroid function provided insights into the pathophysiology of PTH secretion in hemodialysis patients. (b) The magnitude of hyperparathyroidism was the most important predictor of the response to CTR. (c) Before CTR treatment, PTH was sensitive to calcium in Rs, and serum calcium was PTH driven in NRs, and (d) after the CTR-induced increase in serum calcium, calcium suppressed basal PTH relative to maximal PTH in both groups.
Asunto(s)
Calcitriol/uso terapéutico , Agonistas de los Canales de Calcio/uso terapéutico , Hiperparatiroidismo Secundario/tratamiento farmacológico , Hiperparatiroidismo Secundario/etiología , Glándulas Paratiroides/efectos de los fármacos , Glándulas Paratiroides/fisiopatología , Diálisis Renal/efectos adversos , Calcio/sangre , Femenino , Humanos , Hiperparatiroidismo Secundario/fisiopatología , Masculino , Persona de Mediana Edad , Hormona Paratiroidea/sangre , Resultado del TratamientoRESUMEN
In vitro studies of parathyroid glands removed from dialysis patients with secondary hyperparathyroidism and hypercalcemia have demonstrated the presence of an increased set point of parathyroid hormone (PTH) stimulation by calcium (set point [PTHstim]), suggesting an intrinsic abnormality of the hyperplastic parathyroid cell. However, clinical studies on dialysis patients have not observed a correlation between the set point (PTHstim) and the magnitude of hyperparathyroidism. In the present study, 58 hemodialysis patients with moderate to severe hyperparathyroidism (mean PTH 780 +/- 377 pg/ml) were evaluated both before and after calcitriol treatment to establish the relationship among PTH, serum calcium, and the set point (PTHstim) and to determine whether changes in the serum calcium, as induced by calcitriol treatment, modified these relationships. Calcitriol treatment decreased serum PTH levels and increased the serum calcium and the setpoint (PTHstim); however, the increase in serum calcium was greater than the increase in the setpoint (PTHstim). Before treatment with calcitriol, the correlation between the set point (PTHstim) and the serum calcium was r = 0.82, p < 0.001, and between the set point (PTHstim) and PTH was r = 0.39, p = 0.002. After treatment with calcitriol, the correlation between the set point (PTHstim) and the serum calcium remained significant (r = 0.70, p < 0.001), but the correlation between the set point (PTHstim) and PTH was no longer significant (r = 0.09); moreover, a significant correlation was present between the change in the set point (PTHstim) and the change in serum calcium that resulted from calcitriol treatment (r = 0.73, p < 0.001). The correlation between the residual values (deviation from the regression line) of the set point (PTHstim), derived from the correlation between PTH and the set point (PTHstim), and serum calcium was r = 0.77, p < 0.001 before calcitriol and r = 0.72, p < 0.001 after calcitriol. In conclusion, the set point (PTHstim) increased after a sustained increase in the serum calcium, suggesting an adaptation of the set point to the existing serum calcium; the increase in serum calcium resulting from calcitriol treatment was greater than the increase in the set point (PTHstim); the set point (PTHstim) was greater in hemodialysis patients with higher serum PTH levels; and the correlation between PTH and the set point (PTHstim) may be obscured because the serum calcium directly modifies the set point (PTHstim).
Asunto(s)
Adaptación Fisiológica , Calcio/sangre , Hiperparatiroidismo Secundario/sangre , Hormona Paratiroidea/metabolismo , Diálisis Renal , Adulto , Anciano , Biometría/métodos , Calcitriol/uso terapéutico , Femenino , Humanos , Hiperparatiroidismo Secundario/tratamiento farmacológico , Modelos Lineales , Masculino , Persona de Mediana Edad , Estimulación QuímicaRESUMEN
BACKGROUND: Based on in vitro studies, the set point of calcium has often been considered to represent an intrinsic property of parathyroid gland function. However, in the dialysis patient, the serum calcium does not consistently reflect the magnitude of hyperparathyroidism; in addition, little information is available on whether the PTH-calcium curve is modified by sustained changes in the serum calcium. The present study in haemodialysis patients was designed to evaluate whether the set point of calcium and the dynamics of PTH secretion were modified by sustained changes in the serum calcium. METHODS: To accomplish the goal of the study and obtain a wide range of changes in the serum calcium, haemodialysis patients were dialysed with either a 1.75 mM (group I) or a 1.25 mM (group II) calcium dialysate for 2 weeks, and were then changed to a 1.25 mM (group I) or a 1.75 mM (group II) calcium dialysate for an additional 2 weeks. At the end of the first and second 2-week periods, low and high calcium studies were performed to obtain PTH-calcium curves. RESULTS: In group I, the serum ionized calcium decreased with the lower calcium dialysate (P < 0.02) and the set point of calcium was reduced (P < 0.02); in group II, the serum calcium did not change and the set point of calcium was not modified. When both groups were evaluated together, the delta serum calcium correlated directly with the delta set point of calcium (r = 0.87, P < 0.001) and inversely with the delta PTH (r = -0.73, P < 0.005); at the same time, an inverse correlation was observed between the delta PTH and the delta set point of calcium (r = -0.67, P < 0.01). Moreover, the delta serum calcium correlated with both the delta ratio of basal/maximal PTH (r = -0.71, P < 0.005) and the change in predialysis serum calcium necessary to maximally stimulate PTH (r = 0.84, P < 0.001); these latter two are indicators of the position of PTH along the PTH-calcium curve. Finally, in group I the entire PTH-calcium curve shifted to the left on the 1.25 mM calcium dialysate as compared with the 1.75 mM calcium dialysate. CONCLUSION: The findings of the present study indicate that: (1) the set point of calcium followed sustained changes in the serum calcium independently of PTH secretion, and (2) the parathyroid gland was able both to adjust the position of PTH secretion on the PTH-calcium curve and to adapt PTH secretion to the existing serum calcium concentration.
Asunto(s)
Calcio/sangre , Hormona Paratiroidea/metabolismo , Diálisis Renal , Adaptación Fisiológica , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To determine the prevalence of the different Chlamydia trachomatis genotypes in Portuguese patients. METHODS: Urogenital isolates (n = 240) derived from attenders of various clinics in the Lisbon area were differentiated into genovars by genotyping with restriction fragment length polymorphism (RFLP) analysis of the PCR amplified omp1 gene. RESULTS: Genotype E was the most common for both men (47.9%) and women (43.8%). Genotypes D and F were the second most prevalent for men (11.3%) and genotype H was the second most prevalent for women (19.5%). Genotypes F, G, D, in women and H, G, I, in men, were found in a lower percentage of cases. Genotypes B, Ba, J, K, L1 and L2 were very rarely detected. CONCLUSIONS: With one exception, the overall distribution of Chlamydia trachomatis genotypes in our study is similar to what has been observed in other western countries. The only exception is the unusual prevalence of genotype H among women. The clinical manifestations associated with this and other genotypes were similar.