A Porcine Model of Zika Virus Infection to Profile the In Utero Interferon Alpha Response.

Pigs are highly relevant to model human in utero Zika virus (ZIKV) infection because both species have similar physiology, genetics, immunity, fetal brain development, and postnatal brain growth. The virus causes persistent in utero infection and replicates in the fetal brain, fetal membranes, and placenta. Subclinical persistent in utero infection in mid-gestation also increases interferon alpha (IFN-α) levels in fetal blood plasma and amniotic fluid. Moreover, we demonstrated altered IFN-α responses in porcine offspring affected with subclinical in utero ZIKV infection. Elevated levels of in utero type I interferons were suggested to play a role in fetal pathology. Thus, the porcine model may provide an understanding of ZIKV-induced immunopathology in fetuses and sequelae in offspring, which is important for the development of targeted interventions. Here, we describe surgery, ultrasound-guided in utero injection, postoperative monitoring, sampling, and cytokine testing protocols.

A percutaneous fetal cardiac catheterization technique for pulmonary valvuloplasty and valvulotomy in a mid-gestation lamb model.

OBJECTIVE: We aimed to assess the feasibility of using a percutaneous transhepatic cardiac catheterization technique to perform fetal pulmonary valvuloplasty and valvulotomy under ultrasound guidance at mid-gestation. METHOD: In 13 mid-gestation fetal lambs without cardiac pathology, percutaneous transhepatic cardiac catheterization was used to position a coronary angioplasty catheter within the pulmonary valve. The balloon was inflated/deflated several times, simulating pulmonary valvuloplasty. In another two fetal lambs, a guidewire tip was positioned against the pulmonary valve, and unipolar diathermy was applied to simulate perforation of an atretic valve. RESULTS: Percutaneous access followed by right heart catheterization was successful in all cases. One fetus died following right ventricle perforation. Simulated pulmonary valvuloplasty was successful in nine cases using catheters with 6-mm-long balloons but unsuccessful in two cases (both survived) using 12-mm-long balloons. In one case, the catheter could not be inserted as the cannula became dislodged. Diathermy of the pulmonary valve was successful in both attempts. CONCLUSION: We successfully simulated in utero perforation and dilation of the pulmonary valve using percutaneous transhepatic access in fetal lambs. The technique has potential for clinical translation into treatment for human fetuses with critical pulmonary stenosis or pulmonary atresia with intact ventricular septum.

Intraluminal tracheal occlusion using a modified 8-mm Z-stent in a sheep model of left-sided congenital diaphragmatic hernia.

OBJECTIVE: To evaluate pulmonary growth and development after fetoscopic intraluminal tracheal occlusion (FITO) using a modified 8-mm Z-stent in an ovine model of congenital left-sided diaphragmatic hernia (CDH). METHODS: Thirty-three time-dated ewes were studied: Group I: healthy controls; Group II: CDH controls (untreated); Group III: CDH treated with FITO. CDH was created in Groups II and III at 70-80 days' gestation. FITO was performed at 100-110 days. Left lung histological, morphometric, immunohistochemical and biochemical studies were conducted after delivery and euthanasia at 138 days. RESULTS: Fifteen (45%) animals (Group I: 3; Group II: 5; Group III: 7) were available for analysis. The left lung parenchymal volume to fetal weight ratios were similar between Groups I and III (p = 0.24), and higher than Group II (p < 0.05III (79 versus 75%, p = 0.26), compared to 41% in Group II (p < 0.05). Pulmonary hypoplasia occurred in 1/7 (16%) in the FITO group, compared to 100% in Group II and 0% in Group I (p = .003). DNA and protein were significantly increased in Group III (p < 0.001). The concentration of type II pneumocytes was similar between healthy controls and the FITO group, and was paradoxically increased in untreated hernia fetuses. There was no histological evidence of tracheal injury. CONCLUSION: FITO with a modified 8-mm Z-stent is associated with lung growth and maturation similar to controls without obvious deleterious effects. A phase I clinical trial of FITO with the modified 8-mm Z-stent in severe CDH patients seems warranted.

Metodologia aplicada na avaliação de fetos suínos abortados e natimortos / Methodology used in the evaluation of stillborns and aborted fetuses from swine

Este artigo revisa dados relativos à realização de necropsia em fetos suínos abortados e natimortos. Aspectos descritos incluem coleta de material, procedimentos de necropsia, achados macroscópicos e histopatológicos alguns dos quais de pouco ou nenhum significado patológico são frequentemente observados numa rotina de diagnóstico e geralmente interpretados erroneamente como lesões reais ou de importância.

This paper reviews information on necropsies in stillborn and aborted fetuses from swine. Aspects dealt with include sampling collection, necropsy procedures, gross and histopathological findings, some of which are of little or no pathological significance but often observed in the routine diagnostic work and misinterpreted as real or important lesions.

Intra-vesicle administration of D-cloprostenol for induction of abortion in mid-gestation bitches.

This study evaluated a new method for mid-gestation termination in the bitch, which consisted of ultrasound-guided administration of a single dose of d-cloprostenol, a PGF(2alpha) analogue, into a single gestational sac. Effects on serum progesterone concentration (P(4)) were also investigated. The study was performed between days 28 and 35 of gestation on 15 privately owned crossbred bitches, randomly divided into two groups: group A comprised 10 bitches treated with 15 microg per head d-cloprostenol diluted in 0.8 ml sterile saline (final volume 1 ml); group B comprised 5 bitches treated with 1 ml of sterile saline solution (0.9% NaCl), administered in the same way. In all bitches of group A, fetal death was successfully induced within 5 days (mean: 3.1 days, S.D. 1.2) with no clinical or behavioural complications. Mild adverse effects were observed in two bitches, each weighing less than 10 kg, including salivation, defecation and hyperventilation, which disappeared within 15 min. None of the subjects in group B aborted within 10 days post-treatment. In group A, P(4) declined 2.8 days before pregnancy termination to a mean value below 30 nmol/l (S.D. 2.9 nmol/l). However, two bitches showed a higher concentration of P(4) throughout the sampling period. Our study demonstrates that intra-vesicle administration of a single low dose of D-cloprostenol is an effective and safe technique for induction of abortion, which offers an additional option for termination of unwanted pregnancy in the mid-gestation bitch.

Transesophageal echocardiography in fetal sheep. A monitoring tool for open and fetoscopic cardiac procedures.

BACKGROUND: Cardiac procedures in exteriorized fetuses or assisted by fetoscopy require monitoring capabilities not attended by conventional maternal transabdominal echocardiography. METHODS: We, therefore, assessed the potential of fetal transesophageal echocardiography (TEE) utilizing an intravascular ultrasound catheter (IVUC) for fetal cardiac monitoring. We inserted a 10-F-10-MHz IVUC into the esophagus in 12 exteriorized fetal sheep and by a fetoscopic approach in 4 fetal sheep. Cardiac events were observed. Heart rate, cardiac rhythm, patency of the foramen ovale and ductus arteriosus, and the width of the branch pulmonary arteries could be assessed in all fetuses. Ventricular contractility could be assessed only in fetuses weighing less than 2.5 kg. Larger fetuses did not allow adequate imaging of the apical portion of the ventricles because of limited tissue penetration of the IVUC. Fetal TEE permitted placing small guide wires in the cardiac atria and left ventricle. Short-lived premature beats following intracardiac manipulations of these wires could be observed by fetal TEE in all cases. RESULTS: At autopsy, no complications from IVUC insertion were observed in the exteriorized fetuses. Fetoscopic placement of the IVUC resulted in minor perioral skin erosion in two nonexteriorized fetuses. CONCLUSIONS: In conclusion, fetal TEE can be achieved with minor fetal injury and may provide useful information during open and fetoscopic cardiac procedures. Further improvements in IVUC design will permit the application of this technique to monitor human fetal cardiac procedures.