Morbilidad respiratoria en prematuros tardíos y término tempranos / Respiratory morbidity in late preterm and early term infant

INTRODUCCIÓN: Los Recién Nacidos prematuros tardíos (RNPTT) y los Recién Nacidos de Término Temprano (RNTt) son considerados una población de riesgo, con altos índices de ingreso hospitalario y morbimortalidad, mayor cantidad de días de internación y altas tasas de reingreso hospitalario en comparación a los Recién Nacidos de Término Tardío (RNTT). El Síndrome de distrés respiratorio es uno de los principales diagnósticos al ingreso, requiriendo distintos modos de soporte respiratorio, por lo tanto, requieren de cuidados especiales en unidades de media o alta complejidad, significando así un importante costo en salud. OBJETIVOS: Comparar la frecuencia en que se presenta la morbilidad respiratoria (MR) entre RNPTT y en RNTt Vs Recién Nacido a Termino Tardío (RNTT). Establecer factores asociados a MR. Describir los distintos modos de soporte respiratorio utilizados. PACIENTES Y MÉTODOS: Se incluyeron a todos los RNPTT (34 a 36 SEG), y RNTt (37 a 38 SEG) y se compararon con todos los pacientes RNTT (39 a 41 SEG) durante los años 2011 a 2015. Se excluyó a pacientes con malformación o síndrome genético, o derivados de otro centro médico. Análisis estadístico: La frecuencia de MR se consignó en porcentajes. La misma se comparó en ambos grupos utilizando la prueba de Chicuadrado y se realizó el cálculo de Odss Ratio. Las variables maternas o neonatales asociadas a MR se compararon entre los pacientes con o sin MR utilizando prueba U de Mann-Whitney para las variables continuas y Chi-cuadrado para variables categóricas. Las variables con un valor de P ≤ 0.1 en el análisis univariado se incluyeron en un modelo multivariado de regresión logística. El soporte terapéutico utilizado fue descripto en porcentajes y comparados mediante prueba de Chicuadrado y evaluados mediante odss ratio. RESULTADOS: Durante el periodo evaluado se analizaron los datos de 10512 pacientes de los cuales 766 (7,8%) fueron RNPTT, 3654 (92,6%) RNTt y 6087 (57,90%) RNTT. La frecuencia de MR en los RNPTT fue de 202 (26,4%), en los RNTt fue de 115 (3,15%) Vs 46 (0,76%) en los RNTT. El Odss ratio para MR entre RNPTT y RNTt comparado con RNTT respectivamente fue: OR 47.03, IC95% 33.7 a 65.53, P 0.0001, OR 4.26, IC95% 3.02 a 6.02, P 0.0001. (Siendo los RNTT el grupo control. Ver tabla). En el análisis multivariado se observaron factores de riesgo asociados a MR: Patología asociada al embarazo (OR 4,248, IC95% 2,918 a 6,184, P 0.0001), el Apgar menor a 7 a los 5 min (OR 15,09, IC95% 4,64 a 49,03, P 0.0001), el nacimiento por cesárea (OR 2,96 IC95% 2,32 a 3,78, P 0.0001), sexo masculino (OR 1,5 IC95% 1,21 a 2,01, 0,001). En la evaluación en toda la población general se observó al Retardo de Crecimiento Intrauterino (RCIU) como factor protector de MR, (OR 0.51, IC95% 0,29 a 0,92, P 0.029). Los datos en relación al soporte de oxígeno se muestran en la Tabla1. CONCLUSION: Los recién nacidos prematuros tardíos y los recién nacido termino temprano presentaron mayor morbilidad respiratoria comparado con los recién nacidos termino tardío. Los factores de riesgo más preponderantes para MR fueron la prematurez, el nacimiento por cesárea, nacer con Apgar menor a 7 a los 5 min y la existencia de patología materna asociada al embarazo. Los RNPTT y RNTT son una población de riesgo (mayor requerimiento de internación, más días de internación, mayor morbilidad respiratoria y mayor soporte de oxigeno), por lo que se deben de adoptar medidas preventivas para lograr disminuir los factores de riesgo que generan el nacimiento prematuro tardío y término temprano y así lograr disminuir los índices de morbi mortalidad y costos en salud que estos implican. (AU)

INTRODUCTION: Late Preterm Newborns (LPN) and Early Term newborns (ETN) are considered to be at risk, because they have high rates of hospital admission, morbidity and mortality, more days of hospitalization, and high rates of hospital readmission compared To Late term Newborns (LTN). Respiratory distress syndrome is one of the major diagnoses on admission, requiring different modes of respiratory support, therefore, require special care in medium or high complexity neonatal units, meaning a significant health cost. OBJETIVES: Compare the frequency of respiratory morbidity (RM) between late preterm and early term infants Vs complete or late term newborns. Establish factors associated with RM. Describe the different modes of oxigen respiratory support used. PATIENTS AND METHODS: All LPN (34-36 SEGs) and ETN (37-38 SEGs) were included and compared to all LTN (39-41 SEGs) during the years 2011 to 2015. Were excluded patients With malformation or genetic syndrome, or derived from another medical center. Statistical analysis: The frequency of RM was recorded in percentages. The same was compared in both groups using the Chi-square test and the Odss Ratio calculation was performed. Maternal or neonatal variables associated with RM were compared between patients with or without RM using Mann-Whitney U test for continuous variables and Chisquare for categorical variables. Variables with a value of P ≤ 0.1 in the univariate analysis were included in a multivariate logistic regression model. The therapeutic support used was described in percentages and compared by chi-square test and evaluated by odss ratio. RESULTS: Data from 10512 patients were analyzed in the evaluation periode, of which 766 (7.8%) were LPN, 3654 (92.6%) ETN and 6087 (57.90%) LTN. The frequency of RM in the LPN was 202 (26.4%), in the ETN it was 115 (3.15%) vs 46 (0.76%) in the LTN, the odss ratio for RM comparing LPN and ETN with LTN respectively was: OR 47.03, 95% CI 33.7 to 65.53, P 0.0001, OR 4.26, IC95% 3.02 to 6.02, P 0.0001 (LTN being the control group. See table). In the multivariate analysis it was observed the risk factors asociated with RM: the pathology associated with pregnancy (OR 4.248, 95% CI 2.918 to 6.184, P 0.0001), Apgar less than 7 at 5 min (OR 15.09, 95% CI 4.64 to 49.03, P 0.0001). Cesarean birth (OR 2.96, IC95% 2.32 a 3.78, P 0.0001) and Male sex (OR 1,5 IC95% 1,21 a 2,01 P 0,001). In the evaluation in the general population, the Intrauterine Growth Retardation (IUGR) was observed as a protective factor of MR, (OR 0.51, 95% CI 0.29 to 0.92, P 0.029). The data in relation to the oxygen support are shown in Table 1. CONCLUSION: Late preterm infants and early term infants presented higher respiratory morbidity compared to late term newborns. The most important risk factors for RM were prematurity, cesarean birth, birth with Apgar less than 7 at 5 minutes and the existence of maternal pathology associated with pregnancy. The LPN and ETN are a population at risk (greater requirement of hospitalization, more days of hospitalization, greater respiratory morbidity and greater support of oxygen), so that preventive actions must be taken to reduce the risk factors who give late preterm and early term birth and thus reduce morbidity rates and health costs that these imply. (AU)

Grasshopper hunchback expression reveals conserved and novel aspects of axis formation and segmentation.

While the expression patterns of segment polarity genes such as engrailed have been shown to be similar in Drosophila melanogaster and Schistocerca americana (grasshopper), the expression patterns of pair-rule genes such as even-skipped are not conserved between these species. This might suggest that the factors upstream of pair-rule gene expression are not conserved across insect species. We find that, despite this, many aspects of the expression of the Drosophila gap gene hunchback are shared with its orthologs in the grasshoppers S. americana and L. migratoria. We have analyzed both mRNA and protein expression during development, and find that the grasshopper hunchback orthologs appear to have a conserved role in early axial patterning of the germ anlagen and in the specification of gnathal and thoracic primordia. In addition, distinct stepped expression levels of hunchback in the gnathal/thoracic domains suggest that grasshopper hunchback may act in a concentration-dependent fashion (as in Drosophila), although morphogenetic activity is not set up by diffusion to form a smooth gradient. Axial patterning functions appear to be performed entirely by zygotic hunchback, a fundamental difference from Drosophila in which maternal and zygotic hunchback play redundant roles. In grasshoppers, maternal hunchback activity is provided uniformly to the embryo as protein and, we suggest, serves a distinct role in distinguishing embryonic from extra-embryonic cells along the anteroposterior axis from the outset of development - a distinction made in Drosophila along the dorsoventral axis later in development. Later hunchback expression in the abdominal segments is conserved, as are patterns in the nervous system, and in both Drosophila and grasshopper, hunchback is expressed in a subset of extra-embryonic cells. Thus, while the expected domains of hunchback expression are conserved in Schistocerca, we have found surprising and fundamental differences in axial patterning, and have identified a previously unreported domain of expression in Drosophila that suggests conservation of a function in extra-embryonic patterning.

Ectopic pregnancy: changes in serum human chorionic gonadotropin concentration.

In 93 patients with surgically proved ectopic gestation, the initial serum beta-human chorionic gonadotropin (hCG) concentration ranged from 2.0 to 5260 ng/ml; in 33 (35%) the values were below 100 ng/ml. Of 25 patients with serial hCG data, 20 showed a plateau or fall in serum concentrations over at least 48 hours, thereby identifying the gestation as nonviable. Sixty-four patients underwent sonographic evaluation; 35 of these also underwent at least one quantitated hCG determination. Correlating a single hCG value with the sonographic diagnosis correctly identified the gestation as nonviable in 21% of the cases, but a definite diagnosis was not possible in the rest. For the clinically stable patient with a suspected ectopic pregnancy, serial hCG determinations offer a useful technique for evaluating gestational viability.

Effects of indomethacin on uterine capillary permeability and blastocyst development in rabbits.

Increased capillary permeability at implantation sites was demonstrated in rabbits by extravasation of intravascular blue dye on day 7 of pregnancy. Subcutaneous administration of indomethacin (Id, 8 mg/kg twice daily) on days 4-6 of pregnancy inhibited this uterine blueing response and appeared to reduce the size of implantation swellings. To test the latter observation blastocyst diameter and development of the embryonic disk were assessed at 144 hr post coitum. In females receiving indomethacin at the dose level which inhibited uterine blueing, blastocysts were significantly smaller than those from control females. Developmental staging of embryonic disks revealed only slight differences between the smaller (Id-treated) blastocysts and control blastocysts. No effect of Id was seen on ovarian function as judged by luteal weights and plasma progesterone and estradiol levels. Since the major biological effects of indomethacin are due to its inhibition of prostaglandin synthesis, it appears that prostaglandins may play a role in the uterine response to blastocyst stimulation and in the expansion of blastocysts in the rabbit.

Assay of estriol-16alpha-(beta-D-glucuronide) in pregnancy urine with a specific antiserum.

A rapid, direct radioimmunoassay for estriol-16alpha-(beta-D-glucuronide) in pregnancy urine has been developed by use of immunogens in which the estriol glucuronide hapten is linked through positions 2 or 4 of ring A to bovine serum albumin or agarose gel. The resultant antibodies cross react less than 1% with other estriol conjugates, estradiol conjugates, or unconjugated estrogens. Pregnanediol-3-glucuronide cross reacts less than 0.5%. This high degree of specificity of the antibodies allows for a 10,000-fold dilution of pregnancy urine to be assayed directly without interference from other steroids or urinary constituents. Good linear correlation was obtained for urinary-estriol glucuronide equivalents measured in the same subjects by our routine colorimetric method which separates and measures free estriol after hydrolysis. With an accelerated antibody-antigen equilibration of 20 minutes at 40 degrees, 10 samples can be easily processed in less than 90 minutes. The method also allows for the evaluation of variations in the excretion pattern of one estrogen conjugate in normal and high-risk pregnancies.

Glucose metabolism by human placental villi.

1. Glucose phosphorylation rates of about 1 mumole/g./min. have been measured at room temperature in homogenates of human placental chorionic villi, and these rates are relatively constant throughout gestation. 2. This reaction has an apparent K(m) for glucose of 3x10(-5)m both in early and term placenta. 3. Human foetal membranes, the amnion and chorion, also phosphorylate glucose at a rate about equal to that of the placenta. 4. On incubation of intact bits of villus tissue from 8-12-week or full-term placenta with labelled pyruvate, followed by paper chromatography of the tissue extract, the following distribution of label was observed: residual pyruvate, 40-60%; lactate, 30-50%; glucose, 6%; fructose, 7%; sorbitol, 0.6%. 5. The concept of the placenta acting as a foetal liver during early pregnancy is inconsistent with the observation that glucose production by this organ persists up to term.