Static and dynamic responses to hyperoxia of normal placenta across gestation with T2*-weighted MRI sequences.

OBJECTIVES: T2*-weighted magnetic resonance imaging (MRI) sequences have been identified as non-invasive tools with which to study placental oxygenation in vivo. This study aimed to use these to investigate both static and dynamic responses to hyperoxia of the normal placenta across gestation. METHODS: We conducted a single-center prospective study including 52 uncomplicated pregnancies. Two T2*-weighted sequences (T2* relaxometry) were performed, one before and one after maternal hyperoxia. The distribution of placental T2* values was modeled by fitting a gamma probability density function (T2* ~ Γ α ß ), describing the structure of the histogram using the mean T2* value, the shape parameter (α) and the rate (ß). A dynamic acquisition (blood-oxygen-level-dependent (BOLD) MRI) was also performed before and during maternal oxygen supply, until placental oxygen saturation had been achieved. The signal change over time was modeled using a sigmoid function, to determine the intensity of enhancement (ΔBOLD (% with respect to baseline)), a temporal variation coefficient (λ (min-1), controlling the slope of the curve) and the maximum steepness (Vmax (% of placental enhancement/min)). RESULTS: The histogram analysis of the T2* values in normoxia showed a whole-placenta variation, with a decreasing linear trend in the mean T2* value (Pearson's correlation coefficient (R) = -0.83 (95% CI, -0.9 to -0.71), P < 0.001), along with an increasingly peaked and narrower distribution of T2* values with advancing gestation. After maternal hyperoxia, the mean T2* ratios (mean T2*hyperoxia/mean T2*baseline) were positively correlated with gestational age, while the other histogram parameters remained stable, suggesting a translation of the histogram towards higher values with a similar appearance after maternal hyperoxia. ΔBOLD showed a non-linear increase across gestation. Conversely, λ showed an inverted trend across gestation, with a weaker correlation (R = -0.33 (95% CI, -0.58 to -0.02), P = 0.04, R2 = 0.1). As a combination of ΔBOLD and λ, the changes in Vmax throughout gestation were influenced mainly by the changes in ΔBOLD and showed a positive non-linear correlation with gestational age. CONCLUSIONS: Our results suggest that the decrease in the T2* placental signal as gestation progresses does not reflect placental dysfunction. The BOLD dynamic signal change is representative of a free-diffusion model of oxygenation and highlights the increasing differences in oxygen saturation between mother and fetus as gestation progresses (ΔBOLD) and in the placental permeability to oxygen (λ). © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Postnatal outcome following fetal aortic valvuloplasty for critical aortic stenosis.

OBJECTIVE: To report our experience of fetal aortic valvuloplasty (FAV) for critical aortic stenosis (AS), with a focus on the postnatal evolution of the patients. METHODS: This was a retrospective study including all fetuses with critical AS which underwent FAV in a single center between January 2011 and June 2022. FAV was performed under ultrasound guidance. Technical success was based upon balloon inflation across the aortic valve and improvement of the antegrade aortic flow across the aortic valve. At birth, a biventricular circulation (BVC) strategy was decided assuming the left ventricular (LV) systolic and diastolic function would ensure the systemic circulation. RESULTS: Sixty-three FAV procedures were performed in 58 fetuses, at a median (range) gestational age of 26.2 (20.3-32.2) weeks. The procedure was technically successful in 50/58 (86.2%) fetuses. There were 11/58 (19.0%) cases of in-utero demise and 9/58 (15.5%) terminations of pregnancy. No patient was liveborn after an unsuccessful procedure. Thirty-eight (65.5%) infants were liveborn, at a median (range) gestational age of 38.1 (29.0-40.6) weeks, of whom 21 (55.3%) required prostaglandin treatment. Twenty-eight of the 38 (73.7%) liveborn children (48.3% of the study population) entered the BVC pathway at birth. Among them, 20 (71.4%) required an aortic valvuloplasty procedure at birth (11 (55.0%) percutaneous balloon, nine (45.0%) surgical) and eight (28.6%) did not require any treatment at birth, but, of these, five (62.5%) underwent surgical valvuloplasty between day 26 and day 1200 of age. Eleven (39.3%) of the infants with BVC at birth required a second intervention and four (14.3%) of them required a third intervention. Two (7.1%) infants who entered the BVC pathway at birth underwent conversion to univentricular circulation (UVC). None of the surviving children with BVC developed pulmonary hypertension. The overall survival rate in those with BVC at birth was 22/28 (78.6%) at a median (range) follow-up of 23.3 (2.0-112.6) months. Ten of the 58 (17.2%) patients had UVC at birth. Among these, six (60.0%) received compassionate care from birth and four (40.0%) underwent surgery. Three of the 10 patients who were UVC at birth were still alive at the latest follow-up assessment, at a median (range) gestational age of 24.3 (8.3-48.7) months. CONCLUSIONS: FAV for critical AS led to increase of antegrade aortic flow in 86.2% of fetuses, with BVC being achieved in 48.3% (73.7% of the liveborn cases). Among patients with BVC at birth, the rate of reintervention was high, but 78.6% of these children were alive at the latest evaluation. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Albendazole sulphoxide administered prior to mating andits relation with fertilization and mouse embryo development / Albendazol sulfóxido administrado previo al apareamiento y su relación con la fertilización y el desarrollo embrionario de ratón

The aim of this work was to evaluate the effect of albendazole sulphoxide (ABZSO) administered to Balb C mice prior to mating on fertilization rate and preimplantational embryo development. Twenty four female mice 5-8 weeks of age were superovulated by intraperitoneal injection of 7.5 UI of equine chorionic gonadotropin (eCG, Novormon®, Laboratorios Syntex S.A., Argentina); 48 h later they received 10 IU of human chorionic gonadotropin (hCG, Profasi®, Laboratorios Serono, Méjico) and were paired with males of proven fertility. Females received 100 mg/kg or 200 mg/kg of ABZSO orally at the time of hCG administration, prior to mating. The control group received carboxymethylcellulose, vehicle used to prepare the drug suspension. Pregnant females were killed by cervical dislocation at day 4 of pregnancy and non fertilized oocyte and embryos were flushed from uteri. The possible effects of ABZSO were evaluated considering the fertilization rate, the total number of collected embryos per female; the percentage of embryos morphologically normal; the differentiation rate (determined by the relation between the number of blastocyst and the total of morphologically normal embryos) and the cleavage rate determined by counting the nuclei. The variables were analyzed on a per litter basis using the Kruskal-Wallis test. The fertilization rate was lower in females administered ABZSO at a dose of 200 mg/kg (P<0.05). However, no statistically significant differences were found in the embryonic parameters after the administration of 100 mg/kg or 200 mg/kg of ABZSO compared to the untreated control group (P>0.05). In conclusion, a single acute exposure to ABZSO prior to mating at around the time of fertilization at a dose higher than the one usually administered in human and veterinary medicine affects the fertilization rate but it has no adverse effects on early embryo development.

El objetivo de este trabajo fue evaluar el efecto de albendazol sulfóxido (ABZSO) administrado a ratonas Balb C previo al apareamiento, sobre la tasa de fertilización y el desarrollo embrionario preimplantacional. Se utilizaron 24 hembras de 5 a 8 semanas de edad las que fueron inducidas a superovular por inyección intraperitoneal de 7,5 UI de gonadotrofina coriónica equina (eCG, Novormon®, Laboratorios Syntex S.A. Argentina) seguidas, 48 h más tarde por 10 UI de gonadotrofina coriónica humana (hCG, Profasi®, Laboratorios Serono, México). Al momento de recibir la dosis de hCG, fueron apareadas con machos de fertilidad probada. Las hembras fueron dosificadas oralmente con ABZSO disuelto en carboximetilcelulosa en dosis de 100 mg/kg (Grupo 100) y 200 mg/kg (Grupo 200) previo al apareamiento. El grupo control recibió carboximetilcelulosa. Las hembras preñadas fueron sacrificadas por dislocación cervical en el día 4 de preñez y se recolectaron ovocitos sin fertilizar y embriones preimplantacionales mediante el lavado de cuernos uterinos. Se determinó la tasa de fertilización, el número promedio de embriones recolectados por hembra, el porcentaje de embriones morfológicamente normales, el porcentaje de diferenciación y la velocidad de clivaje estimada por recuento de núcleos. Las variables fueron analizadas sobre la base de la camada utilizando el test de Kruskal-Wallis. La tasa de fertilización resultó menor para hembras que recibieron albendazol sulfóxido a razón de 200 mg/kg de peso (P<0,05); no obstante, no se observaron diferencias significativas en los parámetros embrionarios luego de la administración de 100 mg/kg ó 200 mg/kg de ABZSO comparado con el grupo control (P>0,05). En conclusión, la exposición aguda de ABZSO realizada previo al apareamiento a una dosis mayor de aquella utilizada en medicina humana y veterinaria afecta la tasa de fertilización pero no muestra efectos adversos sobre el desarrollo embrionario temprano.

Comparación entre las ecuaciones CKD-EPI y MDRD para la estimación del filtrado glomerular en pacientes con enfermedad renal crónica / Comparison between CKD-EPI and MDRD-equations to estimate glomerular filtration rate in chronic kidney disease patients

La ecuación MDRD para la estimación del índice de filtrado glomerular (IFG), es la estrategia más utilizada para evaluar pacientes con enfermedad renal crónica (ERC). Sin embargo, puede subestimar el IFG con el riesgo de asignar al paciente a estadios más avanzados de ERC. La nueva ecuación CKD-EPI, mejoraría la exactitud y precisión de las estimaciones. Sus autores sugieren que reemplace a la anterior. No habiendo comparaciones de estas ecuaciones aplicadas en un gran número de pacientes en nuestro país, nuestro objetivo fue realizarla en una amplia cohorte de pacientes. Se evaluó la concordancia de asignación en estadios de ERC entre ambas ecuaciones, tomando como referencia los datos surgidos de MDRD. Se calculó la media de las diferencias de los IFG obtenidos empleando ambas ecuaciones y se aplicó el análisis estadístico de Bland-Altman. Se estudió una cohorte de 9 319 pacientes con una media de creatinina sérica de 1.60 ± 1.03 mg/dl, 67% de sexo femenino y edad media 58 ± 20 años. En el grupo total, CKD-EPI presentó una media de IFG 0.61 ml/min/1.73 m² mayor que MDRD (p: NS). En los estadios 2 y 3A las medias del IFG fueron respectivamente 6.95 ± 4.76 y 3.21 ± 3.31, y la concordancia de 81 y 74%. El porcentaje de pacientes con un IFG menor de 60 ml/min/1.73 m², se redujo de 76.3% (MDRD) a 70.1% (CKD-EPI). Por lo tanto, la nueva ecuación CKD-EPI disminuye el número de pacientes con IFG debajo de 60 ml/min/1.73 m² y asigna estadios de IFG más elevado a un número mayor de pacientes.

The MDRD equation to estimate glomerular filtration rate (GFR) is the most widely used strategy to assess chronic kidney disease. Nonetheless, for the individual patient the true GFR can be underestimated with the risk of diagnosing a more elevated CKD stage. This novel CKD-EPI equation would improve accuracy and precision of estimations, and several authors recommend this new equation replace the former. In our country there is only a limited registration of these comparisons performed on a large number of patients. Therefore, our aim was to develop a comparison in a wide cohort of patients. The concordance between both equations to assign the GFR stages was determined by using the MDRD formula as a reference. The mean difference of GFR obtained with both equations as well as the Bland-Altman analysis were calculated. A cohort of 9 319 individuals, of whom 67% were females, aged 58 ± 20 years, with serum creatinine values of 1.6 ± 1.03 mg/dl, was studied. In the whole group, CKD-EPI displayed an average GFR 0.61 ml/min/1.73 m² larger than MDRD (p: NS). For CKD stages 2 and 3A the mean estimated GFR difference was 6.95 ± 4.76 and 3.21 ± 3.31, while the concordance was 81 and 74% respectively. The percentage of patients with GFR < 60 ml/min/1.73 m², decreased from 76.3% with the former equation to 70.1% with the latter. The novel equation CKD-EPI reduces the number of patients with GFR values lower than 60 ml/min/1.73 m² and consequently assigns a higher GFR stage to a considerable quantity of individuals.