Dose-related cardiac outcomes in response to postnatal dexamethasone treatment in premature lambs

BACKGROUND

Postnatal corticosteroids are used in the critical care of preterm infants for the prevention and treatment of bronchopulmonary dysplasia. We aimed to investigate the effects of early postnatal dexamethasone therapy and dose on cardiac maturation and morphology in preterm lambs.

METHODS

Lambs were delivered prematurely at ~128 days of gestational age and managed postnatally according to best clinical practice. Preterm lambs were administered dexamethasone daily at either a low-dose (n = 9) or a high-dose (n = 7), or were naïve to steroid treatment and administered saline (n = 9), over a 7-day time-course. Hearts were studied at postnatal Day 7 for gene expression and assessment of myocardial structure.

RESULTS

High-dose dexamethasone treatment in the early postnatal period led to marked differences in cardiac gene expression, altered cardiomyocyte maturation and reduced cardiomyocyte endowment in the right ventricle, as well as increased inflammatory infiltrates into the left ventricle. Low-dose exposure had minimal effects on the preterm heart.

CONCLUSION

Neonatal dexamethasone treatment led to adverse effects in the preterm heart in a dose-dependent manner within the first week of life. The observed cardiac changes associated with high-dose postnatal dexamethasone treatment may influence postnatal growth and remodeling of the preterm heart and subsequent long-term cardiac function.

Long-term Health-related Quality of Life in Patients on Active Surveillance for Prostate Cancer: A Systematic Review

CONTEXT

Active surveillance (AS) represents the preferred treatment option in patients with low-risk prostate cancer. Optimised patient selection has enabled more patients to be managed with AS for a longer time. Thus, there is growing interest in its effect on long-term quality of life compared with interventional management.

OBJECTIVE

To perform a systematic review evaluating the long-term patient-reported outcomes regarding mental health, and sexual and urinary function in patients on AS.

EVIDENCE ACQUISITION

We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. We included series assessing validated patient-reported outcomes of health-related quality of life, and sexual and urinary function in AS patients followed up for at least 5 yr.

EVIDENCE SYNTHESIS

Our search yielded 1854 citations, including 19 papers involving 3643 patients on AS, 14 651 patients receiving surgery or radiotherapy, and 2478 controls without prostate cancer. In ten studies, major differences were observed in sexual and urinary symptoms between groups, such as better sexual function and fewer irritative urinary symptoms in patients on AS, though overall functional outcomes were comparable. In all studies, health-related quality of life for patients on AS was better than, or similar to, that for patients who had undergone surgery or radiotherapy and comparable with that for individuals without cancer.

CONCLUSIONS

We observed differences in specific functional outcomes between patients on AS and surgery or radiotherapy, ≥5 yr after treatment. Patients on AS reported good quality of life, similar to that in individuals without prostate cancer. AS should continue to be a recommended management strategy for appropriately selected patients.

PATIENT SUMMARY

Active surveillance is an accepted pathway for patients with low-risk localised prostate cancer. Previous literature has shown that it did not negatively affect short-term quality of life. This review finds that long-term quality of life for these patients is similar to that for people without prostate cancer.

A decade of declining prostatectomy margin positivity within a prostate cancer clinical quality registry

CONTEXT

Positive surgical margin (PSM) on radical prostatectomy (RP) is associated with an increased risk of biochemical recurrence and use of salvage therapies. Given these adverse consequences, exploration of time trends and predictors of PSM will improve the patient outcomes following surgery for prostate cancer.

METHODS

Pathological data from RP patients treated from 2011 to 2020 was extracted from the Victorian Prostate Cancer Outcomes Registry. This is a clinical quality registry that regularly benchmarks and reports back to individual clinicians the PSM percentage for their patients. Trends in PSM over time were visualized with separate running mean plots for both pT2 and pT3/4 disease. Predictors of PSM were explored with multivariable regression with date of surgery, surgical method, and hospital type, public or private, entered as covariates.

RESULTS

In total, 12,394 patients formed the sample with PSM recorded in 25% (n = 3,141) of patients, 12% (777/6,640) in pT2 disease and 41% (2,364/5,754) in pT3/4 disease. Comparing 2011-12 to 2019-20, the pT3/4 PSM proportion declined from 50% to 38% while pT2 percentages were steady at 13%. In "high volume" institutions, pT2 PSM fell from 12% to 6.5%. Independent predictors of lower PSM were robotic vs. open method and being treated at a private vs. public institution.

CONCLUSION

A clear decline in the proportion of pT3 PSM was observed in a large prostate cancer registry. Proposed explanatory factors include improved technical proficiency with robotic surgery and participation in a registry-based quality improvement initiative.

Self-reported lack of energy or feeling depressed 12 months after treatment in men diagnosed with prostate cancer within a population-based registry

OBJECTIVE

Feeling depressed and lethargic are common side effects of prostate cancer (PCa) and its treatments. We examined the incidence and severity of feeling depressed and lack of energy in patients in a population based PCa registry.

METHODS

We included men diagnosed with PCa between 2015 and 2019 in Victoria, Australia, and enrolled in the Prostate Cancer Outcomes Registry. The primary outcome measures were responses to two questions on the Expanded Prostate Cancer Index Composite (EPIC-26) patient reported instrument: problems with feeling depressed and problems with lack of energy 12 months following treatment. We evaluated associations between these and age, cancer risk category, treatment type, and urinary, bowel, and sexual function.

RESULTS

Both outcome questions were answered by 9712 out of 12,628 (77%) men. 981 patients (10%) reported at least moderate problems with feeling depressed; 1563 (16%) had at least moderate problems with lack of energy and 586 (6.0%) with both. Younger men reported feeling depressed more frequently than older men. Lack of energy was more common for treatments that included androgen deprivation therapy than not (moderate/big problems: 31% vs. 13%), irrespective of disease risk category. Both outcomes were associated with poorer urinary, bowel, and sexual functional domain scores.

CONCLUSIONS

Self-reported depressive feelings and lack of energy were frequent in this population-based registry. Problems with feeling depressed were more common in younger men and lack of energy more common in men having hormonal treatment. Clinicians should be aware of the incidence of these symptoms in these at-risk groups and be able to screen for them.

Moderate preterm birth affects right ventricular structure and function and pulmonary artery blood flow in adult sheep

KEY POINTS

Preterm birth occurs when the heart muscle is immature and ill-prepared for the changes in heart and lung function at birth. MRI imaging studies show differences in the growth and function of the heart of young adults born preterm, with the effects more pronounced in the right ventricle. The findings of this study, conducted in sheep, showed that following moderate preterm birth the right ventricular wall was thinner in adulthood, with a reduction in the number and size of the heart muscle cells; in addition, there was impaired blood flow in the main artery leading from the right ventricle to the lungs. The findings indicate that being born only a few weeks early adversely affects the cellular structure of the right ventricle and blood flow to the lungs in adulthood. The reduced number of heart muscle cells has the potential to deleteriously affect right ventricular growth potential and function.

ABSTRACT

Preterm birth prematurely exposes the immature heart to the haemodynamic transition at birth, which has the potential to induce abnormal cardiac remodelling. Magnetic resonance imaging studies in young adults born preterm have shown abnormalities in the gross structure of the ventricles (particularly the right ventricle; RV), but the cellular basis of these alterations is unknown. The aim of this study, conducted in sheep, was to determine the effect of moderate preterm birth on RV cellular structure and function in early adulthood. Male singleton lambs were delivered moderately preterm (132 ± 1 days; n = 7) or at term (147 ± 1 days; n = 7). At 14.5 months of age, intra-arterial blood pressure and heart rate were measured. Pulmonary artery diameter and peak systolic blood flow were determined using ultrasound imaging, and RV stroke volume and output calculated. Cardiomyocyte number, size, nuclearity and levels of cardiac fibrosis were subsequently assessed in perfusion-fixed hearts using image analysis and stereological methods. Blood pressure (systolic, diastolic and mean), heart rate, levels of myocardial fibrosis and RV stroke volume and output were not different between groups. There was, however, a significant reduction in RV wall thickness in preterm sheep, and this was accompanied by a significant reduction in peak systolic blood flow in the pulmonary artery and in RV cardiomyocyte number. Cellular changes in the RV wall and reduced pulmonary artery blood flow following preterm birth have the potential to adversely affect cardiac and respiratory haemodynamics, especially when the cardiovascular system is physiologically or pathologically challenged.

The effects of preterm birth and its antecedents on the cardiovascular system

INTRODUCTION

Preterm birth occurs in approximately 10% of all births worldwide. It prematurely exposes the developing cardiovascular system to the hemodynamic transition that occurs at birth and to the subsequent functional demands of life ex utero. This review describes the current knowledge of the effects of preterm birth, and some of its common antecedents (chorioamnionitis, intra-uterine growth restriction, and maternal antenatal corticosteroid administration), on the structure of the myocardium.

MATERIAL AND METHODS

A thorough literature search was conducted for articles relating to how preterm birth, and its antecedents, affect development of the heart. Given that sheep are an excellent model for the studies of cardiac development, this review has focused on experimental studies in sheep as well as clinical findings.

RESULTS

Our review of the literature demonstrates that individuals born preterm are at an increased risk of cardiovascular disease later in life, including increased mean arterial pressure, abnormally shaped and sub-optimally performing hearts and changes in the vasculature. The review highlights how antenatal corticosteroids, intra-uterine growth restriction, and exposure to chorioamnionitis also have the potential to impact cardiac growth in the preterm newborn.

CONCLUSIONS

Preterm birth and its common antecedents (antenatal corticosteroids, intra-uterine growth restriction, and chorioamnionitis) have the potential to adversely impact cardiac structure immediately following birth and in later life.

Validation of a Three-Dimensional Method for Counting and Sizing Podocytes in Whole Glomeruli

Podocyte depletion is sufficient for the development of numerous glomerular diseases and can be absolute (loss of podocytes) or relative (reduced number of podocytes per volume of glomerulus). Commonly used methods to quantify podocyte depletion introduce bias, whereas gold standard stereologic methodologies are time consuming and impractical. We developed a novel approach for assessing podocyte depletion in whole glomeruli that combines immunofluorescence, optical clearing, confocal microscopy, and three-dimensional analysis. We validated this method in a transgenic mouse model of selective podocyte depletion, in which we determined dose-dependent alterations in several quantitative indices of podocyte depletion. This new approach provides a quantitative tool for the comprehensive and time-efficient analysis of podocyte depletion in whole glomeruli.

Substantial Increases Occur in Serum Activins and Follistatin during Lung Transplantation

Background

Lung transplantation exposes the donated lung to a period of anoxia. Re-establishing the circulation after ischemia stimulates inflammation causing organ damage. Since our published data established that activin A is a key pro-inflammatory cytokine, we assessed the roles of activin A and B, and their binding protein, follistatin, in patients undergoing lung transplantation.

Methods

Sera from 46 patients participating in a published study of remote ischemia conditioning in lung transplantation were used. Serum activin A and B, follistatin and 11 other cytokines were measured in samples taken immediately after anaesthesia induction, after remote ischemia conditioning or sham treatment undertaken just prior to allograft reperfusion and during the subsequent 24 hours.

Results

Substantial increases in serum activin A, B and follistatin occurred after the baseline sample, taken before anaesthesia induction and peaked immediately after the remote ischemia conditioning/sham treatment. The levels remained elevated 15 minutes after lung transplantation declining thereafter reaching baseline 2 hours post-transplant. Activin B and follistatin concentrations were lower in patients receiving remote ischemia conditioning compared to sham treated patients but the magnitude of the decrease did not correlate with early transplant outcomes.

Conclusions

We propose that the increases in the serum activin A, B and follistatin result from a combination of factors; the acute phase response, the reperfusion response and the use of heparin-based anti-coagulants.

Alcohol exposure during late ovine gestation alters fetal liver iron homeostasis without apparent dysmorphology

High levels of alcohol (ethanol) exposure during fetal life can affect liver development and can increase susceptibility to infection after birth. Our aim was to determine the effects of a moderate level of ethanol exposure in late gestation on the morphology, iron status, and inflammatory status of the ovine fetal liver. Pregnant ewes were chronically catheterized at 91 days of gestation (DG; term ∼145 DG) for daily intravenous infusion of ethanol (0.75 g/kg maternal body wt; n = 8) or saline ( n = 7) over 1 h from 95 to 133 DG. At necropsy (134 DG), fetal livers were collected for analysis. Liver weight, general liver morphology, hepatic cell proliferation and apoptosis, perivascular collagen deposition, and interleukin ( IL) -1β, IL-6, or IL-8 mRNA levels were not different between groups. However, ethanol exposure led to significant decreases in hepatic content of ferric iron and gene expression of the iron-regulating hormone hepcidin and tumor necrosis factor ( TNF) -α (all P < 0.05). In the placenta, there was no difference in transferrin receptor, divalent metal transporter 1, and ferritin mRNA levels; however, ferroportin mRNA levels were increased in ethanol-exposed animals ( P < 0.05), and ferroportin protein tended to be increased ( P = 0.054). Plasma iron concentration was not different between control and ethanol-exposed groups; control fetuses had significantly higher iron concentrations than their mothers, whereas maternal and fetal iron concentrations were similar in ethanol-exposed animals. We conclude that daily ethanol exposure during the third-trimester-equivalent in sheep does not alter fetal liver morphology; however, decreased fetal liver ferric iron content and altered hepcidin and ferroportin gene expression indicate that iron homeostasis is altered.

Loss of GGN leads to pre-implantation embryonic lethality and compromised male meiotic DNA double strand break repair in the mouse

The integrity of male germ cell genome is critical for the correct progression of spermatogenesis, successful fertilization, and proper development of the offspring. Several DNA repair pathways exist in male germ cells. However, unlike somatic cells, key components of such pathways remain largely unidentified. Gametogenetin (GGN) is a testis-enriched protein that has been shown to bind to the DNA repair protein FANCL via yeast-two-hybrid assays. This finding and its testis-enriched expression pattern raise the possibility that GGN plays a role in DNA repair during spermatogenesis. Herein we demonstrated that the largest isoform GGN1 interacted with components of DNA repair machinery in the mouse testis. In addition to FANCL, GGN1 interacted with the critical component of the Fanconi Anemia (FA) pathway FANCD2 and a downstream component of the BRCA pathway, BRCC36. To define the physiological function of GGN, we generated a Ggn null mouse line. A complete loss of GGN resulted in embryonic lethality at the very earliest period of pre-implantation development, with no viable blastocysts observed. This finding was consistent with the observation that Ggn mRNA was also expressed in lower levels in the oocyte and pre-implantation embryos. Moreover, pachytene spermatocytes of the Ggn heterozygous knockout mice showed an increased incidence of unrepaired DNA double strand breaks (DSBs). Together, our results suggest that GGN plays a role in male meiotic DSB repair and is absolutely required for the survival of pre-implantation embryos.

Alcohol exposure during late gestation adversely affects myocardial development with implications for postnatal cardiac function

Prenatal exposure to high levels of ethanol is associated with cardiac malformations, but the effects of lower levels of exposure on the heart are unclear. Our aim was to investigate the effects of daily exposure to ethanol during late gestation, when cardiomyocytes are undergoing maturation, on the developing myocardium. Pregnant ewes were infused with either ethanol (0.75 g/kg) or saline for 1 h each day from gestational days 95 to 133 (term ∼145 days); tissues were collected at 134 days. In sheep, cardiomyocytes mature during late gestation as in humans. Within the left ventricle (LV), cardiomyocyte number was determined using unbiased stereology and cardiomyocyte size and nuclearity determined using confocal microscopy. Collagen deposition was quantified using image analysis. Genes relating to cardiomyocyte proliferation and apoptosis were examined using quantitative real-time PCR. Fetal plasma ethanol concentration reached 0.11 g/dL after EtOH infusions. Ethanol exposure induced significant increases in relative heart weight, relative LV wall volume, and cardiomyocyte cross-sectional area. Ethanol exposure advanced LV maturation in that the proportion of binucleated cardiomyocytes increased by 12%, and the number of mononucleated cardiomyocytes was decreased by a similar amount. Apoptotic gene expression increased in the ethanol-exposed hearts, although there were no significant differences between groups in total cardiomyocyte number or interstitial collagen. Daily exposure to a moderate dose of ethanol in late gestation accelerates the maturation of cardiomyocytes and increases cardiomyocyte and LV tissue volume in the fetal heart. These effects on cardiomyocyte growth may program for long-term cardiac vulnerability.

Cardiac remodelling as a result of pre-term birth: implications for future cardiovascular disease

AIMS

Pre-term birth affects 10-12% of live births and occurs when the myocardium is still developing; therefore, the final structure of the myocardium could be altered. We hypothesized that, in response to pre-term birth, structural remodelling occurs within the myocardium which enables the immature heart muscle to adapt to the haemodynamic transition at birth but results in persistent alterations in its structure. Our objective was to determine how pre-term birth alters the final structure of the myocardium.

METHODS AND RESULTS

Using sheep, pre-term birth was induced at 0.9 of term; hearts were examined at 9 weeks after term-equivalent age, when cardiomyocyte proliferation and maturation have ceased. In pre-term lambs, we found that cardiomyocytes of both ventricles and the interventricular septum were hypertrophied. Cardiomyocyte maturation in pre-term lambs was altered in that there was a greater proportion of mononucleated, polyploid (4n) cardiomyocytes in both ventricles compared with controls; importantly, induction of polyploidy is associated with irreversible stress-related changes in DNA. We also found a six- to seven-fold increase in collagen deposition, usually accompanied by lymphocytic infiltration.

CONCLUSION

We conclude that pre-term birth leads to remodelling of the myocardium that alters its final structure. This may programme for long-term cardiac vulnerability.