Effect of hypoxemia on fetal ventricular deformation in a chronically instrumented sheep model

We hypothesized that in near-term sheep fetuses, hypoxemia changes myocardial function as reflected in altered ventricular deformation on speckle-tracking echocardiography. Fetuses in 21 pregnant sheep were instrumented. After 4 d of recovery, fetal cardiac function was assessed by echocardiography at baseline, after 30 and 120 min of induced fetal hypoxemia and after its reversal. Left (LV) and right (RV) ventricular cardiac output and myocardial strain were measured. Baseline mean (standard deviation [ SD]) LV and RV global longitudinal strains were -18.7% (3.8) and -14.3% (5.3). Baseline RV global longitudinal and circumferential deformations were less compared with those of the left ventricle (p = 0.016 and p <0.005). LV, but not RV, global longitudinal strain was decreased (p = 0.003) compared with baseline with hypoxemia. Circumferential and radial strains did not exhibit significant changes. In the near-term sheep fetus, LV global longitudinal and circumferential strains are more negative than RV strains. Acute hypoxemia leads to LV rather than RV dysfunction as reflected by decreased deformation. (C) 2017 World Federation for Ultrasound in Medicine & Biology.Peer reviewe

Nifedipine disturbs fetal cardiac function during hypoxemia in a chronic sheep model at near term gestation

BACKGROUND: Nifedipine is a widely used drug in pregnancies complicated by maternal hypertensive disorders that can be associated with placental insufficiency and fetal hypoxemia. The evidence regarding fetal myocardial responses to nifedipine in hypoxemia is limited. OBJECTIVE: We hypothesized that nifedipine would not impair fetal sheep cardiac function under hypoxemic environment. In particular, we investigated the effects of nifedipine on fetal ventricular functional parameters and cardiac output. STUDY DESIGN: A total of 21 chronically instrumented fetal sheep at 122 to 134 gestational days (term, 145 days) were included in this study. Fetal cardiac function was evaluated by measuring global longitudinal strain, indices describing ventricular systolic and diastolic function, and cardiac outputs using two-dimensional speckle tracking and tissue and spectral pulsed-wave Doppler echocardiography. Fetal carotid artery blood pressure and blood gas values were invasively monitored. After baseline data collection, fetal hypoxemia was induced by maternal hyperoxygenation. After hypoxemia phase data collection, 9 fetuses received nifedipine infusion, and 12 fetuses received saline infusion. Data were collected 30 and 120 minutes after the infusion was started. After 120 minutes of data collection, maternal and fetal oxygenation were normalized, and normoxemia phase data were collected, while infusion was continued. RESULTS: Hypoxemia decreased fetal carotid artery mean arterial pressure from 40 (8) mm Hg to 35 (8) mm Hg (P CONCLUSION: In hypoxemic fetus, nifedipine impaired right ventricular function and reduced its cardiac output. The detrimental effects of nifedipine on fetal right ventricular function were abolished, when normoxemia was restored. Our findings suggest that in a hypoxemic environment nifedipine triggers detrimental effects on fetal right ventricular function.Peer reviewe

Effects of nifedipine and sildenafil on placental hemodynamics and gas exchange during fetal hypoxemia in a chronic sheep model

Introduction We hypothesized that nifedipine and sildenafil would have no detrimental effects on placental hemodynamics and gas exchange under fetal hypoxemia. Methods In 33 chronically instrumented fetal sheep, placental volume blood flow (QPlac) and umbilical artery (UA) vascular impedance were measured by Doppler ultrasonography. Fetal carotid artery blood pressure and blood gas values were monitored. After baseline data collection, maternal and fetal hypoxemia were induced. Following hypoxemia phase data collection, 12 fetuses received sildenafil and 9 fetuses nifedipine infusion, and 12 fetuses served as controls receiving saline infusion. Data were collected 30 and 120 min after infusion was started. Then maternal oxygenation was normalized and normoxemia phase data were collected, while infusion was continued. Results Hypoxemia significantly decreased fetal pO2 and blood pressure. In the sildenafil group at 30- and 120-min hypoxemia + infusion phases, fetal blood pressure and QPlac were significantly lower and pCO2 higher than at baseline without returning to baseline level at normoxemia + infusion phase. In hypoxemia, nifedipine did not affect fetal blood pressure or placental hemodynamics. Both in the sildenafil and nifedipine groups, fetal pO2 remained significantly lower at normoxemia + infusion phase than in the control group. Umbilical artery vascular impedance did not change during the experiment. Discussion In fetal hypoxemia, sildenafil had detrimental effects on placental hemodynamics that disturbed placental gas exchange. Nifedipine did not alter placental hemodynamics in hypoxemia but disturbed placental gas exchange upon returning to normoxemia. Umbilical artery vascular impedance did not reflect alterations in placental hemodynamics.Peer reviewe

Effect of Sildenafil on Pulmonary Circulation and Cardiovascular Function in Near-Term Fetal Sheep During Hypoxemia

Sildenafil is a potential new treatment for placental insufficiency in human pregnancies as it reduces the breakdown of vasodilator nitric oxide. Pulmonary vasodilatation is observed in normoxemic fetuses following sildenafil administration. Placental insufficiency often leads to fetal hypoxemia that can cause pulmonary vasoconstriction and fetal cardiac dysfunction as evidenced by reduced isovolumic myocardial velocities. We tested the hypotheses that sildenafil, when given directly to the hypoxemic fetus, reverses reactive pulmonary vasoconstriction, increases left ventricular cardiac output by increasing pulmonary venous return, and ameliorates hypoxemic myocardial dysfunction. We used an instrumented sheep model. Fetuses were made hypoxemic over a mean (standard deviation) duration of 41.3 (9.5) minutes and then given intravenous sildenafil or saline infusion. Volume blood flow through ductus arteriosus was measured with an ultrasonic transit-time flow probe. Fetal left and right ventricular outputs and lung volume blood flow were calculated, and ventricular function was examined using echocardiography. Lung volume blood flow decreased and the ductus arteriosus volume blood flow increased with hypoxemia. There was a significant reduction in left ventricular and combined cardiac outputs during hypoxemia in both groups. Hypoxemia led to a reduction in myocardial isovolumic velocities, increased ductus venosus pulsatility, and reduced left ventricular myocardial deformation. Direct administration of sildenafil to hypoxemic fetus did not reverse the redistribution of cardiac output. Furthermore, fetal cardiac systolic and diastolic dysfunction was observed during hypoxemia, which was not improved by fetal sildenafil treatment. In conclusion, sildenafil did not improve pulmonary blood flow or cardiac function in hypoxemic sheep fetuses.Peer reviewe

Intratumoral lactate metabolism in Barrett’s esophagus and adenocarcinoma

Background: Monocarboxylate transporters (MCTs) are cell membrane proteins which transport pyruvate, lactate and ketone bodies across the plasma membrane. MCTs are activated in various cancers, but their expression in esophageal adenocarcinoma is not known. The present study was conducted to elucidate the expression of MCTs in esophageal adenocarcinoma and its precursor lesions. Results: Cytoplasmic MCT1, MCT4 and MTCO1 expression linearly increased from normal epithelium to Barrett's mucosa to dysplasia and cancer. Low cytoplasmic MCT1 expression associated with high T-class (P < 0.01), positive lymph node metastases (P < 0.05), positive distant metastases (P < 0.01) and high tumor stage (P < 0.01). High cytoplasmic MCT4 expression correlated significantly with positive distant metastases (P < 0.05). Both low MCT1 and high MCT4 histoscore predicted survival in univariate analysis (P < 0.01). MCT4 histoscore predicted survival in multivariate analysis (P = 0.043; HR 1.8 95%CI 1.0–3.1). MTCO1 expression was not correlated to clinicopathological variables or survival. Materials and Methods: MCT1, MCT4 and mitochondrial cytochrome c oxidase (MTCO1) expression were determined with immunohistochemistry in esophageal specimens from 129 patients with columnar dysplasia or adenocarcinoma. Specimens including normal esophagus (n = 88), gastric (n = 67) or intestinal metaplasia (n = 51), low-grade (n = 42), high-grade dysplasia (n = 37) and esophageal adenocarcinoma (n = 99) were evaluated. Conclusions: Major increase in markers of tumor metabolism occurs during carcinogenesis and progression of esophageal adenocarcinoma. MCT1 and MCT4 are prognostic factors in esophageal adenocarcinoma.Orion Research FoundationThelma Mäkikyrö FoundationPäivikki and Sakari Sohlberg FoundationThe Emil Aaltonen FoundationGeorg C. and Mary Ehrnroot FoundationSigrid Jusélius FoundationFinnish cancer FoundationThe Finnish Medical FoundationPublishe

Tenascin-C and fibronectin in normal esophageal mucosa, Barrett's esophagus, dysplasia and adenocarcinoma.

BACKGROUND: Tenascin-C and fibronectin are adhesive glycoproteins modulating the structure of the extracellular matrix and cellular functions. Their expression and function in esophageal adenocarcinoma is poorly known. The aim of this study was to evaluate the expression of tenascin-C and fibronectin in esophageal adenocarcinoma and its precursor stages. RESULTS: Stromal tenascin-C and fibronectin expression were found in all evaluated lesion types. Expression of both molecules increased from gastric metaplasia towards adenocarcinoma (p<0.05). In carcinomas, tenascin-C expression in the bulk was associated with T-stage (p=0.006), presence of lymph node (p=0.004) and distant organ metastases (p=0.007). Abundant tenascin-C expression associated with poor survival (p=0.034) in univariate analysis. Fibronectin expression associated to T-stage (p=0.030). Expression of tenascin-C or fibronectin in the tumor invasive front was not associated to clinicopathological variables or survival. No significant correlation with tumor/stroma percentage, cancer-associated fibroblasts or mean vascular density was observed with either tenascin-C or fibronectin. METHODS: Tenascin-C and fibronectin were stained immunohistochemically and assessed in esophageal specimens from patients with esophageal adenocarcinoma (n=90) or dysplasia (n=30). Structures and lesion were evaluated including normal esophagus (n=77), gastric (n=61) or intestinal (n=51) metaplasia without dysplasia, and low-grade (n=42) or high-grade (n=34) dysplasia, and esophageal adenocarcinoma (n=90). In carcinomas, both bulk and invasive front were separately evaluated. In addition, tumor/stroma percentage, cancer-associated fibroblasts and mean vascular density were evaluated. CONCLUSIONS: Tenascin-C and fibronectin are upregulated in esophageal adenocarcinoma when compared to Barrett's esophagus and dysplasia. Increased tenascin-C expression is associated with metastasis and poor prognosis in esophageal adenocarcinoma.Orion Research FoundationThelma Mäkikyrö FoundationPäivikki and Sakari Sohlberg FoundationGeorg C. and Mary Ehrnroot FoundationSigrid Juselius FoundationThe Finnish Medical FoundationEmil Aaltonen FoundationPublishe

Foramen ovale blood flow and cardiac function after main pulmonary artery occlusion in fetal sheep

The foramen ovale (FO) accounts for the majority of fetal left ventricular (LV) output. Increased right ventricular afterload can cause a redistribution of combined cardiac output between the ventricles. To understand the capability of the FO to increase its volume blood flow and thus LV output, we mechanically occluded the main pulmonary artery in seven chronically instrumented near-term sheep fetuses. We hypothesized that FO volume blood flow and LV output would increase during main pulmonary artery occlusion. Fetal cardiac function and haemodynamics were assessed by pulsed and tissue Doppler at baseline, 15 and 60 min after occlusion of the main pulmonary artery and 15 min after occlusion was released. Fetal ascending aorta and central venous pressures and blood gas values were monitored. Main pulmonary artery occlusion initially increased fetal heart rate (P <0.05) from [mean (SD)] 158 (7) to 188 (23) beats min(-1) and LV cardiac output (P <0.0001) from 629 (198) to 776 (283) ml min(-1). Combined cardiac output fell (P <0.0001) from 1524 (341) to 720 (273) ml min(-1). During main pulmonary artery occlusion, FO volume blood flow increased (P <0.001) from 507 (181) to 776 (283) ml min(-1). This increase was related to fetal tachycardia, because LV stroke volume did not change. Fetal ascending aortic blood pressure remained stable. Central venous pressure was higher (P <0.05) during the occlusion than after it was released. During the occlusion, fetal pH decreased and PCO2 increased. Left ventricular systolic dysfunction developed while LV diastolic function was preserved. Right ventricular systolic and diastolic function deteriorated after the occlusion. In conclusion, the FO has a limited capacity to increase its volume blood flow at near-term gestation.Peer reviewe

Long-Term Survival After Transhiatal Versus Transthoracic Esophagectomy : A Population-Based Nationwide Study in Finland

Background No population-based studies comparing long-term survival after transhiatal esophagectomy (THE) and transthoracic esophagectomy (TTE) exist. This study aimed to compare the 5-year survival of esophageal cancer patients undergoing THE or TTE in a population-based nationwide setting. Methods This study included all curatively intended THE and TTE for esophageal cancer in Finland during 1987-2016, with follow-up evaluation until 31 December 2019. Cox proportional hazard models provided hazard ratios (HRs) with 95% confidence intervals (CIs) of 5-year and 90-day mortality. The results were adjusted for age, sex, year of operation, comorbidities, histology, neoadjuvant treatment, and pathologic stage. Results A total of 1338 patients underwent THE (n = 323) or TTE (n = 1015). The observed 5-year survival rate was 39.3% after THE and 45.0% after TTE (p = 0.072). In adjusted model 1, THE was not associated with greater 5-year mortality (HR 0.99; 95% CI 0.82-1.20) than TTE. In adjusted model 2, including T stage instead of pathologic stage, the 5-year mortality hazard rates after THE (HR 0.87, 95% CI 0.72-1.05) and TTE were comparable. The 90-day mortality rate for THE was higher than for TTE (adjusted HR 0.72; 95% CI 0.45-1.14). In subgroup analyses, no differences between THE and TTE were observed in Siewert II gastroesophageal junction cancers, esophageal cancers, or pN0 tumors, nor in the comparison of THE and TTE with two-field lymphadenectomy. The sensitivity analysis, including patients with missing patient records, who underwent surgery during 1996-2016 mirrored the main analysis. Conclusions This Finnish population-based nationwide study suggests no difference in 5-year or 90-day mortality after THE and TTE for esophageal cancer.Peer reviewe

Preoperative hemoglobin count and prognosis of esophageal cancer, a population-based nationwide study in Finland

Publisher Copyright: © 2021Background: The prognostic value of preoperative hemoglobin in patients undergoing esophagectomy is unknown. The aim of this study was to examine whether preoperative hemoglobin is associated with prognosis in patients undergoing esophagectomy for cancer. Materials and methods: This was a population-based nationwide retrospective cohort study in Finland, using Finnish National Esophago-Gastric Cancer Cohort (FINEGO). Esophagectomy patients with available preoperative hemoglobin measurement were included. Multivariable cox regression provided hazard ratios (HR) with 95% confidence intervals (CI), adjusted for calendar period of surgery, age at surgery, sex, comorbidity (Charlson Comorbidity Index), tumor histology, tumor stage, neoadjuvant therapy, type of surgery (minimally invasive or open) and annual hospital volume. Results: Of the 1313 patients, 932 (71.0%) were men and 799 (60.9%) had esophageal adenocarcinoma. Overall all-cause mortality was significantly higher in the lowest hemoglobin count tertile (HR 1.26 (1.07–1.47)) compared to the highest tertile, but this association was attenuated after adjustment for confounding. No differences were found between the preoperative hemoglobin groups in the adjusted analyses of 90-day all-cause, 5-year all-cause, and 5-year cancer-specific mortality. Conclusion: In this population-based nationwide study, preoperative hemoglobin count had no independent prognostic significance in esophageal cancer.Peer reviewe