Hematological and biochemical indicators of maturity in foals and their relation to the placental features / Indicadores hematológicos e bioquímicos de maturidade em potros e relação com suas características placentárias

Newborn's health is directly related to gestational conditions and placental efficiency. The aims of this study were: (1) To evaluate hematological and biochemical parameters of foals born from mares with placentitis at birth and at 24h of age, (2) to verify if placental pathology had any influence on neonatal maturity degree through hematological and biochemical response of those foals. According to placental findings (control and placentitis) and neonatal maturity degree (mature and immature), foals were divided into three groups: (1) Control group (n=22), foals born from mares with placentitis and classified as (2) Mature (n=26), and (3) Immature (n=10). The hematocrit and plasma concentration of fibrinogen, total plasma protein, white blood cells count, lactate, glucose, creatinine, urea, albumin, bilirubin, triglyceride, cholesterol, calcium, phosphorus, magnesium, aspartate aminotransferase (AST), creatine kinase (CK), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT) were measured. Placental features were significantly different between neonatal maturity degree (P=0.001). Mares that had acute placentitis foaled more immature neonates (n=8/10; 80%). Concentrations of fibrinogen (P=0.003), creatinine (P=0.021), total cholesterol (P=0.014), AST (P=0.001), GGT (P=0.002), total (P=0.001) and unconjugated bilirubin (P=0.010) were higher at birth in the Immature group, whereas albumin levels were lower (P=0.002). Foals born from mares with placentitis presented hyperlactatemia at 24h of age (P=0.002). Acute placentitis had an influence on the neonatal maturity, allowing an accelerated but incomplete fetal maturation. The monitoring of lactate, fibrinogen, creatinine, bilirubin, cholesterol, albumin, AST, and GGT levels, associated with clinical, physical, and behavior evaluation may contribute as indicators of neonatal maturity.(AU)

A saúde do neonato está diretamente relacionada às condições gestacionais e eficiência placentária. Os objetivos deste estudo foram: (1) avaliar parâmetros hematológicos e bioquímicos de potros nascidos de éguas com placentite ao nascimento e com 24h de vida e (2) verificar se a patologia placentária exerceu influência no grau de maturidade através da resposta hemato-bioquímica destes neonatos. De acordo com os resultados histopatológicos placentários (controle e placentite) e grau de maturidade neonatal (maturo e imaturo), os potros foram divididos em três grupos: grupo controle (n=22); e potros nascidos de éguas com placentite classificados como (2) maturos (n=26) e (3) imaturos (n=10). Foi avaliado hematócrito e concentrações sanguíneas de fibrinogênio, proteína plasmática total, leucócitos totais, lactato, glicose, creatinina, uréia, albumina, bilirrubinas, triglicerídeos, colesterol, cálcio, fósforo, magnésio, aspartato aminotransferase (AST), creatina quinase (CK), fosfatase alcalina (FA) e gama glutamiltranferase (GGT). As características placentárias foram significativamente diferentes entre os graus de maturidade neonatal (P=0.001). Éguas com placentite aguda produziram mais potros imaturos (n=8/10; 80%). No nascimento, os potros imaturos apresentaram maiores concentrações de fibrinogênio (P=0,003), creatinina (P=0,021), colesterol total (P=0,0014), AST (P=0,001), GGT (P=0,002), bilirrubina indireta (P=0,010) e total (P=0,001) e menor concentração de albumina (P=0,002). Os potros nascidos de éguas com placentite apresentaram hiperlactatemia com 24h de vida (P=0,002). A placentite aguda exerceu influência na maturidade neonatal, permitindo uma maturação fetal acelerada, porém, incompleta. Mensurações dos níveis sanguíneos de lactato, fibrinogênio, creatinina, colesterol total, AST, GGT, bilirrubinas e albumina, associado à avaliação clínica, física e comportamental, podem contribuir como indicadores de maturidade neonatal.(AU)

Estradiol cypionate aided treatment for experimentally induced ascending placentitis in mares.

The overall goal of this study was to assess the efficacy of various therapeutic combinations of estradiol cypionate (ECP, a long-acting estrogen) and altrenogest (ALT, a long-acting progestin) in addition to basic treatment for placentitis with trimethoprim-sulfamethoxazole (TMS) and flunixin meglumine (FM). Specific outcomes measured in this experiment were (i) time from induction of bacterial placentitis to delivery, and foal parameters (high-risk, survival, and birth weight); and (ii) serum steroid concentrations (progesterone, 17α-hydroxyprogesterone, 17ß-estradiol, and cortisol) in response to treatment. Pregnant mares (∼300 days gestation, n = 46) were randomly assigned into healthy mares (control group, CONT, n = 8) and mares with experimentally induced ascending placentitis (n = 38). Placentitis was induced via intracervical inoculation of Streptococcus equi subspecies zooepidemicus. Thereafter, placentitis induced mares were randomly assigned into: (1) basic treatment, TMS+FM (n = 8); (2) basic treatment with ALT supplementation, TMS+FM+ALT (n = 8); (3) basic treatment with ECP supplementation, TMS+FM+ECP (n = 6); (4) basic treatment with ALT and ECP supplementation TMS+FM+ALT+ECP (n = 6); and (5) no treatment (INOC, n = 10). Treatments were started 48 h after bacterial inoculation and carried out for ten consecutive days. Blood samples were collected daily, and mares were assessed for signs of placentitis until the mare delivered, or for ten consecutive days after onset of treatment. Steroids were analyzed via RIA. Continuous data were analyzed by ANOVA, and categorical data analyzed by Fisher's exact test. Significance was set at p < 0.05. Foal survival at parturition and seven days post-delivery were similar across treated groups (66.7-100%), and to the CONT group. Similar to CONT group, mares in the TMS+FM+ECP group had no high-risk foals while mares in the other groups had higher incidences (50-75%) (p < 0.05). The inclusion of ECP in the treatments resulted in foals with body weight similar to CONT group (p > 0.05). There were no group effects or time by group interactions on concentrations of steroids assessed herein (p > 0.05). In conclusion, in addition to basic treatment TMS+FM, mares with experimentally induced ascending placentitis benefited from ECP supplementation. Conversely, ALT did not appear to make a difference in outcomes. The immunoassays used for measurements of steroid concentrations did not appear useful to assess treatment response.

Histomorphometry of the placental vasculature and microcotyledons in Thoroughbred mares with chronic laminitis.

The objective of this study was to assess the placental vasculature and microcotyledons in pregnant mares with chronic laminitis. Twenty-six pregnant mares were enrolled in the study, 13 had chronic laminitis (Laminitis Group) and 13 were healthy mares (Healthy Group). Arterial systolic pressure and heart rate were measured in the last 30 days of gestation. After foaling, the fetal membranes were grossly evaluated and samples were harvested for histopathologic examination. All mares had digitalized images taken from chorioallantois for histomorphometry analyses (software-NIH ImageJ). Images were assessed for: (i) arterioles from the allantoic region: total and lumen vascular diameter and vascular wall thickness; (ii) microcotiledonary and capillary area/field. Mares in the Laminitis Group showed hypertension, shorter gestational length, lower placental weight and lower birthweight (p < 0.05) foal in comparison with mares in the Healthy Group. Laminitis mares had a reduction of vascular lumen diameters in the uterine body and pregnant horn (p < 0.05), vascular wall thickening in the pregnant horn (p < 0.05) and smaller capillary area/field in the microcotyledons of uterine body and pregnant horn (p < 0.05). In conclusion, pregnant mares with chronic laminitis presented signs of hypertension syndrome, and vascular abnormalitities in placental vessels such as reduction in the vascular lumen and capillary area in the microcotyledones, and thickening of the vascular wall. Foals born from mares with chronic laminitis showed lower birth weight and shorter gestation lengths.

Estudo de ovários fetais equinos: uma abordagem histológica / Study of fetal equine ovary: an histological approach

O estudo do desenvolvimento embriológico de órgãos reprodutivos representa uma ferramenta importante para a compreensão das particularidades da espécie equina, assim como ampliar os conhecimentos sobre o desenvolvimento de folículos antrais que podem ser utilizados para produção in vitro de embriões. O presente trabalho teve como objetivo descrever as alterações morfológicas de ovários fetais equinos ocorrentes durante o desenvolvimento gestacional. Foram utilizados fetos equinos provenientes de abatedouro. Imediatamente após o abate foi realizada medição da distância cefalococcígea para o cálculo da idade gestacional em dias (dias de gestação - DG) e dissecação dos fetos para a retirada e fixação dos ovários. Foram realizadas avaliações macroscópicas e histológicas pelas técnicas de Hematoxilina-eosina e PAS. Foram utilizados 19 fetos com idade de 50-269 dias de gestação, distribuídos em 9 grupos de DG. Na avaliação macroscópica foi observada diferença entre o volume dos ovários de acordo com a idade gestacional, sendo observado maior volume ovariano entre os dias 210 a 269 de desenvolvimento gestacional. Na avaliação histológica foi observado epitélio de revestimento cúbico e distinção entre as camadas cortical e medular nos ovários fetais a partir de 50-89 DG. As principais características identificadas foram à distinção morfológica entre as camadas cortical e medular nos ovários fetais equinos: os cordões ovígeros surgiram no intervalo de 150-179 DG; o córtex iniciada como uma camada delgada e por volta do 210º dia de gestação apresentou espessamento pelo aumento da quantidade de tecido conjuntivo rico em vasos sanguíneos, o qual se manteve até os estágios finais da gestação; a região medular adquiriu uniformidade estrutural por volta do 150º dia, mostrando células similares em tamanho e vasos sanguíneos de calibre maior. A partir desta etapa, as células medulares diminuíram em tamanho e feixes de tecido conjuntivo denso tornaram esta zona parcialmente dividida.(AU)

The study of embryological development of reproductive organs is an important tool for understanding the particularities of the equine species. Also it is important for increasing knowledge about the development of antral follicles that can be used for in vitro production of embryos. This study aimed to describe the morphological changes of fetal equine ovaries occurring during gestational development. It was used equine fetuses from a slaughterhouse. After slaughter, it was performed the measurement of cefalococcígea distance to calculate the gestational age (days of pregnancy - DP). Afterwards, the ovaries were grossly evaluated, removed and fixed. Then, they were histologically assessed by hematoxylin-eosin and PAS techniques. It was used 19 fetuses aged 50 to 269 days of gestation, distributed in 9 groups divided according to DP. In the grossly evaluation, it was observed differences between the volume of the ovaries according to gestational age, being observed bigger/larger ovarian volume between 210 days to 269 DP. During the histological evaluation, it was observed a simple cuboidal epithelium and a distinction between the cortical and medullary layers in fetal ovaries from 50-89 DP. The main characteristics identified were: the morphological distinction between the cortical and medullary layers in equine fetal ovaries; the ovigerous cords emerged in the interval between 150 and 179 DP; the cortex initiated as a thin layer with an increased amount of connective tissue rich in blood vessels by the 210 DP, structural uniformity acquired in the medular region by the 150 DP, showing similar cells in size and blood vessels of larger caliber. From this stage, the cells in this region had decreased in size and dense connective tissue bundles, which made this zone partially divided.(AU)

Histological features of the placenta and their relation to the gross and data from Thoroughbred mares / Achados histológicos da placenta e sua relação com seus aspectos macroscópicas e dados de éguas Puro Sangue Inglês

The placenta is a transitory organ that originates from maternal and fetal tissues, the function of which is transporting nutrients from the mother to the fetus. The aim of this study was describe the histological features of placentas in healthy Thoroughbred mares at foaling and evaluate their relation with the gross placental and data of these mares. For this study 188 Thoroughbred mares were used. It was performed clinical observation for signs of placentitis during daily health checks and ultrasonic examination monthly to assess the fetus and placenta. All of the mares that exhibited clinical signs of placentitis were treated during gestation. The parturition was assisted, the placentas were grossly evaluated and samples were collected immediately after expulsion. The following data were considered for each mare: age, gestational age, number of parturition, time for placental expulsion, umbilical-cord length, placental weight and clinical signs of placentitis. Histological evaluation of the placentas revealed extensive cytoplasmic vacuolization of the epithelial areolar cells, presence of inflammatory infiltrates and hypoplasia-atrophy of the microcotyledons. Most of the gross placental findings were consistent with the histological results. In conclusion the mares with a vacuolated placental chorionic epithelium were older and had experienced a larger number of births. Great part of the mares with inflammatory infiltrates did not showed any clinical signs of placentitis during gestation.(AU)

A placenta é um órgão transitório originado do tecido fetal e materno, com função de transportar nutrientes da mãe para o feto. O objetivo deste estudo foi descrever os achados histológicos das placentas de éguas Puro Sangue Inglês (PSI) a termo e avaliar sua relação com a macroscopia da placenta e dados dessas éguas. O estudo utilizou 188 éguas PSI. Foram realizadas observações clinicas diárias para presença de sinais clínicos de placentite e ultrassonografia mensal para avaliar saúde do feto e placenta. As éguas que apresentaram sinais clínicos de placentite durante a gestação foram tratadas. Os partos foram assistidos, as placentas avaliadas macroscopicamente e coletadas imediatamente após sua expulsão. Como dados das éguas foram considerados: idade, tempo de gestação, número de partos, tempo de eliminação da placenta, comprimento de cordão umbilical, peso da placenta e sinais clínicos de placentite. A avaliação histológica das placentas demonstrou extensiva vacuolização citoplasmática das células do epitélio coriônico das regiões areolares, presença de infiltrados inflamatórios e hipoplasia-atrofia de microcotilédones. A maior parte dos achados macroscópicos da placenta foram condizentes com os resultados de histologia. Como conclusão, a vacuolização do epitélio coriônico foi característica de éguas mais velhas e com maior número de partos. Grande parte das éguas com infiltrados inflamatórios não demonstraram sinais clínicos de placentite.(AU)