Uterine kallikrein and arterial bradykinin activities and uterine arterial proliferation in response to acute estradiol-17ß exposure in ovariectomized ewes.

Estradiol-17ß (E2) increases kallikrein in rodent and human reproductive tissues. Kallikrein specific activity is increased in the porcine uterus when conceptus E2 is secreted at maternal recognition of pregnancy. When kallikrein acts on kininogen to liberate bradykinin, angiogenic and vasoactive factors are released. The uterus of ovariectomized ewes administered E2 undergoes rapid vascular changes via different patterns of angiogenic and vasoactive factors. Our hypothesis was that E2 would increase the specific activity and protein secretion of tissue kallikrein in endometrial explants culture media (ECM) and ewes exposed to E2 would have uterine arteries that would be more sensitive to the vasodilatory effects of bradykinin. Ovariectomized ewes received 100 mg of E2 implants for 0, 12, 24, or 48 h. After treatment, uterine weights were determined, and caruncles were processed for ECM. Uterine weights and uterine weight per ewe body weight were significantly greater in the 12 and 24 h ewes compared with the 0 h ewes, with the 48 h ewes being similar to the 24 h ewes. There were no statistically significant differences in caruncular tissue kallikrein protein secretion among the treatment groups. There was a tendency (P = 0.09) for duration of E2 exposure to influence tissue kallikrein specific activity where kallikrein activity was greater (P ≤ 0.05) in the 12 and 48 h ewes compared with the 0 h ewes, with 24 h ewes being intermediate (unprotected F test). Uterine arteries from ewes with E2 for 24 and 48 h had more sensitivity to bradykinin, via the bradykinin receptor 2, than uterine arteries from ewes with 0 or 12 h E2 exposure. We fail to reject our hypothesis as E2 did elicit a positive response in tissue kallikrein specific activity and bradykinin response. Further investigations are needed to determine how kallikrein and bradykinin may be involved in vascular remodeling of the ovine uterus.

Infective endocarditis: a retrospective cohort study.

BACKGROUND: Infective endocarditis (IE) is a potentially life-threatening infection of the heart's endocardial surface. Despite advances in the diagnosis and management of IE, morbidity and mortality remain high. AIM: To characterize the demographics, bacteriology and outcomes of IE cases presenting to an Irish tertiary referral centre. DESIGN: Retrospective cohort study. METHODS: Patients were identified using Hospital Inpatient Enquiry and Clinical Microbiology inpatient consult data, from January 2005 to January 2014. Patients were diagnosed with IE using Modified Duke Criteria. Standard Bayesian statistics were employed for analysis and cases were compared to contemporary international registries. RESULTS: Two hundred and two patients were diagnosed with IE during this period. Mean age 54 years. Of these, 136 (67%) were native valve endocarditis (NVE), 50 (25%) were prosthetic valve endocarditis (PVE) and 22 (11%) were cardiovascular implantable electronic device-associated endocarditis. Culprit organism was identified in 176 (87.1%) cases and Staphylococcal species were the most common (57.5%). Fifty-nine per cent of NVE required surgery compared to 66% of PVE. Mean mortality rate was 17.3%, with NVE being the lowest (12.5%) and PVE the highest (32%). Increasing age was also associated with increased mortality. Fifty-three (26.2%) patients had embolic complications. CONCLUSIONS: This Irish cohort exhibited first-world demographic patterns comparable to those published in contemporary international literature. PVE required surgery more often and was associated with higher rates of mortality than NVE. Embolic complications were relatively common and represent important sequelae, especially in the intravenous drug user population. It is also pertinent to aggressively treat older cohorts as they were associated with increased mortality.

Lost but not forgotten: A population-based study of mortality and care trajectories among people living with HIV who are lost to follow-up in Ontario, Canada.

OBJECTIVES: Selection as a consequence of volunteer participation in, and loss to follow-up from, cohort studies may bias estimates of mortality and other health outcomes. To quantify this potential, we estimated mortality and health service use among people living with HIV (PLWH) who were lost to cohort follow-up (LTCFU) from a volunteer clinical HIV-infected cohort, and compared these to mortality and health service use in active cohort participants and non-cohort-participants living with HIV in Ontario, Canada. METHODS: We analysed population-based provincial health databases from 1995 to 2014, identifying PLWH ≥ 18 years old; these included data from participants in the Ontario HIV Treatment Network Cohort Study (OCS), a volunteer, multi-site clinical HIV-infected cohort. We calculated all-cause mortality, hospitalization and emergency department (ED) visit rates per 100 person-years (PY) and estimated hazard ratios (HRs) of mortality, adjusting for age, sex, income, rurality, and immigration status. RESULTS: Among 23 043 PLWH, 5568 were OCS participants. Compared with nonparticipants, participants were younger and less likely to be female, to be an immigrant and to reside in a major urban centre, and had lower comorbidity. Mortality among active participants, participants LTCFU and nonparticipants was 2.52, 3.30 and 2.20 per 100 PY, respectively. After adjustment for covariates, mortality risk was elevated among participants LTCFU compared with active participants (HR 2.26; 95% confidence interval 1.91, 2.68). Age-adjusted hospitalization rates and ED visit rates were highest among participants LTCFU. CONCLUSIONS: Mortality risk and use of health care resources were lower among active cohort participants. Our findings may inform health outcome estimates based on volunteer cohorts, as well as quantitative bias adjustment to correct for such biases.

Late diagnosis, delayed presentation and late presentation among persons enrolled in a clinical HIV cohort in Ontario, Canada (1999-2013).

OBJECTIVES: Timely HIV diagnosis and presentation to medical care are important for treatment and prevention. Our objective was to measure late diagnosis, delayed presentation and late presentation among individuals in the Ontario HIV Treatment Network Cohort Study (OCS) who were newly diagnosed in Ontario. METHODS: The OCS is a multi-site clinical cohort study of people living with HIV in Ontario, Canada. We measured prevalence of late diagnosis [CD4 count < 350 cells/µL or an AIDS-defining condition (ADC) within 3 months of HIV diagnosis], delayed presentation (≥ 3 months from HIV diagnosis to presentation to care), and late presentation (CD4 count < 350 cells/µL or ADC within 3 months of presentation). We identified characteristics associated with these outcomes and explored their overlap. RESULTS: A total of 1819 OCS participants were newly diagnosed in Ontario from 1999 to 2013. Late diagnosis (53.0%) and presentation (54.0%) were common, and a quarter (23.1%) of participants were delayed presenters. In multivariable models, the participants of delayed presentation decreased over calendar time, but that of late diagnosis/presentation did not. Late diagnosis contributed to the majority (> 87%) of late presentation, and the prevalence of delayed presentation was similar among those diagnosed late versus early (13.4 versus 13.4%, respectively; P = 0.99). Characteristics associated with higher odds of late diagnosis/presentation in multivariable analyses included older age at diagnosis/presentation; African, Caribbean and Black race/ethnicity; Indigenous race/ethnicity; female sex; and being a male who did not report sex with men. There were lower odds of late diagnosis/presentation among participants who had ever injected drugs. In contrast, delayed presentation risk factors included younger age at diagnosis and having ever injected drugs. CONCLUSIONS: Late presentation is common in Ontario, as it is in other high-income countries. Our findings suggest that efforts to reduce late presentation should focus on facilitating earlier diagnosis for the populations identified in this analysis.

Impact of a rapid molecular test for positive blood cultures from neonatal intensive care patients on clinical management: a retrospective audit.

BACKGROUND: Both Staphylococcus aureus and coagulase negative Staphylococci are common causes of late-onset neonatal sepsis in the neonatal intensive care unit (NICU), usually relating to intravascular access device infections. AIMS: This project aimed to review the impact on antimicrobial treatment and clinical outcome in the NICU setting, of the introduction of the Xpert MRSA/SA BC test (Cepheid, USA) for the identification of staphylococci in blood cultures. METHODS: A retrospective audit was carried out of the pre- and post-intervention periods; the intervention was the introduction of the Xpert MRSA/SA BC test. RESULTS: In total, 88 neonates had positive blood cultures with Staphylococcus spp., comprising 42 neonates in the pre-intervention and 46 in the post-intervention groups. The pre-intervention group had a higher birth weight (1.541 kg vs. 1.219 kg, p = 0.05) and higher platelet count (288 vs. 224 × 109/L, p = 0.05). There was a trend towards a shorter duration of antimicrobial therapy in term infants and in the length of admission; however, this was not statistically significant (p = 0.2). All of the nine infants post-intervention with significant bacteraemia (S. aureus =3, CoNS =6) were changed to the optimal antimicrobial at the time the result was available. CONCLUSIONS: This study shows that the introduction of the Xpert MRSA/SA BC test can lead to a reduction in the length of admission and duration of antimicrobials in term infants; however, the difference was not statistically significant. All nine infants with clinically significant bacteraemia were treated with the appropriate antimicrobial when the Xpert MRSA/SA BC test result was available.

A tale of two countries: all-cause mortality among people living with HIV and receiving combination antiretroviral therapy in the UK and Canada.

OBJECTIVES: We sought to compare all-cause mortality of people living with HIV and accessing care in Canada and the UK. METHODS: Individuals from the Canadian Observational Cohort (CANOC) collaboration and UK Collaborative HIV Cohort (UK CHIC) study who were aged ≥ 18 years, had initiated antiretroviral therapy (ART) for the first time between 2000 and 2012 and who had acquired HIV through sexual transmission were included in the analysis. Cox regression was used to investigate the difference in mortality risk between the two cohort collaborations, accounting for loss to follow-up as a competing risk. RESULTS: A total of 19 960 participants were included in the analysis (CANOC, 4137; UK CHIC, 15 823). CANOC participants were more likely to be older [median age 39 years (interquartile range (IQR): 33, 46 years) vs. 36 years (IQR: 31, 43 years) for UK CHIC participants], to be male (86 vs. 73%, respectively), and to report men who have sex with men (MSM) sexual transmission risk (72 vs. 56%, respectively) (all P < 0.001). Overall, 762 deaths occurred during 98 798 person-years (PY) of follow-up, giving a crude mortality rate of 7.7 per 1000 PY [95% confidence interval (CI): 7.1, 8.3 per 1000 PY]. The crude mortality rates were 8.6 (95% CI: 7.4, 10.0) and 7.5 (95% CI: 6.9, 8.1) per 1000 PY among CANOC and UK CHIC study participants, respectively. No statistically significant difference in mortality risk was observed between the cohort collaborations in Cox regression accounting for loss to follow-up as a competing risk (adjusted hazard ratio 0.86; 95% CI: 0.72-1.03). CONCLUSIONS: Despite differences in national HIV care provision and treatment guidelines, mortality risk did not differ between CANOC and UK CHIC study participants who acquired HIV through sexual transmission.

Impact of Xpert MRSA/SA blood culture PCR assay on management of positive blood cultures in obstetric patients: a retrospective audit.

BACKGROUND: The Xpert MRSA/SA blood culture assay (Cepheid, USA) is a rapid PCR test which can be used for positive blood cultures where Gram-positive cocci in clusters are seen. It can detect Staphylococcus aureus and also the mecA gene, which encodes for ß-lactam resistance. The assay was introduced into the Rotunda Hospital for positive blood cultures to allow earlier detection of MRSA and methicillin susceptible S. aureus. AIM: To assess the impact of the Xpert MRSA/SA blood culture assay on the management of obstetric patients with a positive blood culture where Gram-positive cocci in clusters were seen. The main outcome measures were duration of intravenous antimicrobials and length of admission. METHODS: Pre-intervention and post-intervention groups were identified relating to whether or not the test was in use at the time. A standardised form was used to retrospectively review the medical notes and laboratory results. RESULTS: There were 35 obstetric patients with positive blood cultures with Gram-positive cocci in clusters in the pre-intervention group and 22 cases in the post-intervention group. All 22 positive blood cultures in the post-intervention period were correctly identified. The antimicrobial duration was reduced from a median of 55.5-43.5 h and length of admission reduced from a median of 66.5-56 h (Mann-Whitney U value = 161, p = 0.46 and U value = 256, p = 0.15, respectively). CONCLUSION: This study has shown a reduction in the median duration of intravenous antimicrobials and admission; however, larger multi-centre studies are needed to evaluate this potential benefit further.

Health and social support services in older adults recently discharged from hospital: service utilisation and costs and exploration of the impact of a home-exercise intervention.

BACKGROUND: Admission to hospital can lead to persistent deterioration in physical functioning, particularly for the more vulnerable older population. As a result of this physical deterioration, older people who have been recently discharged from hospital may be particularly high users of health and social support services. Quantify usage and costs of services in older adults after hospitalisation and explore the impact of a home-exercise intervention on service usage. METHOD: The present study was a secondary analysis of data from a randomised controlled trial (ACTRN12607000563460). The trial involved 340 participants aged 60 years and over with recent hospitalisation. Service use and costs were compared between intervention (12 months of home-exercise prescribed in 10 visits from a physiotherapist) and control groups. RESULTS: 33 % of participants were re-admitted to hospital, 100 % consulted a General Medical Practitioner and 63 % used social services. 56 % of costs were associated with hospital admission and 22 % with social services. There was reduction in General Medical Practitioner services provided in the home in the intervention group (IRR 0.23, CI 0.1 to 0.545, p < 0.01) but no significant between-group difference in service use or in costs for other service categories. CONCLUSION: There appears to be substantial hospital and social service use and costs in this population of older people. No significant impact of a home-based exercise program was evident on service use or costs. TRIAL REGISTRATION: Australian and New Zealand Clinical Trial Registry ACTRN12607000563460 >TrialSearch.

Evaluation of the incidence of pulmonary embolus in the early postoperative period following cemented hemiarthroplasty.

PURPOSE: Little is known regarding the incidence of early postoperative pulmonary embolus (PE) following hip fracture surgery. Clinical suspicion of PE mandates therapeutic anticoagulation, adding a further insult to those of trauma and surgery in a physiologically frail population. The aim of the study was to evaluate for the presence of PEs by performing postoperative CT pulmonary angiography (CTPA) in patients who demonstrated intraoperative, or early postoperative cardiorespiratory lability following surgery with a cemented prosthesis for intracapsular hip fracture. METHODS: All patients undergoing cemented hemiarthroplasty for displaced intracapsular neck of femur fracture were recruited during a 6-month period, and signed consent obtained from the patient or their next of kin for CTPA in the event of any cardiorespiratory instability. Patient demographics, comorbidities were reviewed, and premorbid mobility status documented. RESULTS: 18 of the 66 patients in the study having cemented hemiarthropalsty demonstrated intra- or early postoperative lability, all had early postoperative CTPA scans. 6 of the 18 were noted to have PE. All had more than 1 risk factor for VTE on admission (excluding their injury). Patients diagnosed with PE had a higher ASA grade, and lower mobility scores than those who did not have a PE. CONCLUSIONS: Clinical suspicion alone is inadequate to diagnosis PE in patients undergoing cemented hip arthroplasty. Only 1 in 3 patients suspected of PE on account of intraoperative or immediate postoperative cardiorespiratory lability was found to have a PE based on CTPA. Early postoperative CTPA is helpful to prevent unnecessary anticoagulation for suspected PE.

Relationship between neurocognitive functioning and medication management ability over the first 6 months following allogeneic stem cell transplantation.

Although neurocognitive impairment has been established as a major issue among cancer survivors, the real-world consequences of this impairment are unclear. This study investigated the relationship between neurocognitive functioning and medication management ability over time among 58 patients treated with allogeneic hematopoietic stem cell transplantation (HCT). Participants completed a neuropsychological test battery and a simulated medication management task at three time points: pre-transplant (T0), Day 100 (T1) and 6 months post transplant (T2). Neurocognitively impaired participants performed worse on the medication management task than neurocognitively normal participants at each time point, and were more likely to score in the impaired range of medication management ability post transplant (72% vs 20%, P<0.001 at T1; 67% vs 23%, P=0.013 at T2). In multivariate analyses, worse performance in executive functioning/working memory consistently predicted impaired medication management ability, even when controlling for sociodemographic and clinical confounders (odds ratio=0.89, 95% confidence interval (0.80, 0.98), P=0.023). Lower physical symptom distress also predicted impaired medication management ability, but this effect decreased over time. Self-reported cognitive problems were not correlated with medication management ability at any time point. Findings suggest that poor neurocognitive functioning, particularly in the domain of executive functioning/working memory, is associated with worse medication management ability within the first 6 months after allogeneic HCT.

Chronic blockade of class I PI3-kinase attenuates Ang II-induced cardiac hypertrophy and autophagic alteration.

OBJECTIVE: Chronic Ang II stimulation is linked to cardiac remodeling characterized by fibrosis and cardiac hypertrophy. However, the underlying cellular mechanisms involved are not yet fully known. Here, we studied the molecular mechanisms underlying the chronic effect of Ang II on cardiac hypertrophy, fibrosis, and autophagy. MATERIALS AND METHODS: The role of class I PI3-kinase in these actions of Ang II was studied using lentiviral vector-mediated expression of a dominant negative form of PI3-kinase subunit p85α (Lv-DNp85) in the heart. Ang II was infused subcutaneously for 4 weeks on rats using osmotic pumps. Cardiac hypertrophy, fibrosis, reactive oxygen species (ROS), and autophagy were examined in four groups of rats (Ang II+Lv-DNp85, Ang II+Lv-GFP, Saline+Lv-DNp85, Saline+Lv-GFP). RESULTS: Chronic infusion of Ang II induced severe cardiac hypertrophy and perivascular fibrosis in the heart. These effects were associated with a significant reduction in LC3 II and elevation in ROS levels, suggesting marked impairment of cardiac autophagy and increased generation of ROS. Cardiac transduction of Lv-DNp85 significantly attenuated Ang II-induced impairment of autophagy and elevation of ROS, as well as Ang II-induced cardiac hypertrophy and perivascular fibrosis. To study the cellular mechanisms underlying those actions of Ang II, phosphorylated Akt and mTOR were measured in hearts from these rats. Ang II increased phosphorylation of Akt and mTOR; and cardiac transduction of Lv-DNp85 significantly abolished Ang II-induced phosphorylation of Akt and mTOR, a signaling pathway inhibiting autophagy. CONCLUSIONS: These results demonstrate that class I PI3-kinase, via activation of the Akt-mTOR pathway, is involved in Ang II-induced impairment of autophagy, elevation of ROS, cardiac hypertrophy, and fibrosis, suggesting a novel target for cardiac protection.

Neurocognitive impairment in a large sample of homeless adults with mental illness.

OBJECTIVE: This study examines neurocognitive functioning in a large, well-characterized sample of homeless adults with mental illness and assesses demographic and clinical factors associated with neurocognitive performance. METHOD: A total of 1500 homeless adults with mental illness enrolled in the At Home Chez Soi study completed neuropsychological measures assessing speed of information processing, memory, and executive functioning. Sociodemographic and clinical data were also collected. Linear regression analyses were conducted to examine factors associated with neurocognitive performance. RESULTS: Approximately half of our sample met criteria for psychosis, major depressive disorder, and alcohol or substance use disorder, and nearly half had experienced severe traumatic brain injury. Overall, 72% of participants demonstrated cognitive impairment, including deficits in processing speed (48%), verbal learning (71%) and recall (67%), and executive functioning (38%). The overall statistical model explained 19.8% of the variance in the neurocognitive summary score, with reduced neurocognitive performance associated with older age, lower education, first language other than English or French, Black or Other ethnicity, and the presence of psychosis. CONCLUSION: Homeless adults with mental illness experience impairment in multiple neuropsychological domains. Much of the variance in our sample's cognitive performance remains unexplained, highlighting the need for further research in the mechanisms underlying cognitive impairment in this population.

Tackling the social and structural drivers of HIV in Canada.

There is new hope that we can significantly reduce HIV rates. The United Nations AIDS organization, UNAIDS, has challenged all countries to strive for aggressive targets that could significantly bend the curve on HIV infections and deaths: 90% of people living with HIV diagnosed; 90% of people diagnosed on treatment; and 90% of people on treatment virally suppressed. This new optimism is largely driven by strong research findings that early and ongoing HIV treatment improves individual health outcomes and reduces people's viral load, making them less infectious. However, the risk of HIV infection is far from evenly distributed among populations most at risk. Those most at risk will find it hardest to reach these targets as they are caught in a syndemic (synergistic epidemic) of intertwining health and social issues. Our research, and that of others, shows that those who are in a syndemic of co-occurring mental health, addiction and social issues (e.g. homelessness, food insecurity) are significantly more likely to fall out of care, less likely to adhere to treatment and less likely to achieve/maintain an undetectable viral load. Intervention studies have found that a combination approach to HIV prevention and treatment that goes beyond primary care and mental health tools to include social and structural interventions has a protective effect, and can reduce risk and improve adherence. People living with and at risk of HIV need better access to social and mental health services as well as clinical treatment services that will help them achieve and maintain optimal health and well-being. We strongly encourage those in the HIV sector across the country to identify a common vision, with clear goals and targets. With concerted and targeted efforts, a focus on program and implementation science, and a willingness to see and treat HIV as a social as well as a biomedical problem-the fourth decade of HIV in Canada could well be the last.

Cognitive function and fatigue after diagnosis of colorectal cancer.

BACKGROUND: Cognitive impairment and fatigue have been associated with cancer and its treatment. We present baseline data from a large longitudinal study that evaluates cognitive function, fatigue, and potential underlying mechanisms following diagnosis of colorectal cancer (CRC). PATIENTS AND METHODS: We evaluated CRC patients with stage I-III disease before or after surgery, participants with limited metastatic disease and healthy controls (HC). Neuropsychological evaluation included clinical and computerised tests. Participants completed questionnaires for fatigue and quality of life (QOL)-(FACT-F), anxiety/depression, and cognitive symptoms (FACT-Cog). Ten cytokines, clotting factors, sex hormones, carcinoembryonic antigen (CEA), and apolipoprotein E genotype were evaluated. Primary end points were cognitive function on clinical tests evaluated by a Global Deficit score (GDS) and fatigue. Associations between test results, demographic, and disease related factors were explored. RESULTS: We assessed 291 participants with early-stage disease [median age 59 (23-75) years, 63% men], 72 with metastatic disease, and 72 HC. Using GDS, 45% (126/281) of participants with early-stage CRC had cognitive impairment versus 15% (11/72) of HC (odds ratio 4.51, 95% confidence interval 2.28-8.93; P < 0.001), with complex processing speed, attention/working memory, and verbal learning efficiency being most affected. Women with early-stage CRC had greater cognitive impairment than men [55/105 (52%) versus 71/176 (40%), P < 0.050]. Cognitive symptoms were self-reported by 21% (59/286) of early-stage patients versus 17% (12/72) of HC; fatigue by 52% (149/287) of early-stage patients and 26% (19/72) of HC (P < 0.0001). Women reported more fatigue than men (P = 0.003). Fatigue, QOL, anxiety/depression, and cognitive symptoms were associated with each other (r = 0.43-0.71), but not with neuropsychological performance. Most cytokines were elevated in cancer patients. Cognitive function was not associated with cytokines, sex hormones, clotting factors, CEA, or apolipoprotein E genotype. CONCLUSIONS: The incidence of cognitive impairment was three to five times higher in CRC patients than HC, with women having higher impairment rates than men. The cognitive impairment profile suggests dysfunction primarily in fronto-subcortical brain systems. TRIAL REGISTRATION: NCT00188331.

Effect of maternal nutrient restriction and melatonin supplementation from mid to late gestation on vascular reactivity of maternal and fetal placental arteries.

INTRODUCTION: Maternal nutrient restriction and decreased scotophase concentrations of melatonin have been associated with severely compromised pregnancies. We hypothesized that melatonin supplementation in a compromised pregnancy enhances the bradykinin (BK)-induced relaxations of placental arteries thereby ensuring sufficient umbilical blood flow to the developing fetus. METHODS: Pregnant ewes (n = 31) were fed an adequate (ADQ) or nutrient restricted (RES) diet supplemented with 5 mg of melatonin (MEL) or without melatonin (CON) from day 50 to 130 of gestation. On day 130 of gestation, the maternal (caruncular; CAR) and fetal (cotyledonary; COT) placental arteries were suspended in organ chambers for isometric tension recording. RESULTS: There were no treatment or dietary effects on CAR arteries for any vasoactive agent. However, in COT arteries, MEL ewes were more sensitive (P < 0.01) to bradykinin-induced relaxation than CON ewes. There was a melatonin by nutritional level interaction (P < 0.01) with sodium nitroprusside-induced relaxation of COT arteries where CON-RES were more sensitive to sodium nitroprusside compared to CON-ADQ, which was in contrast to when ewes were fed MEL. There was a significant melatonin by nutritional interaction (P = 0.04) for responsiveness to norepinephrine. The sensitivity of the COT arteries to norepinephrine in CON-RES ewes was decreased compared to CON-ADQ. Melatonin supplementation, regardless of maternal dietary intake, resulted in COT arteries having similar responsiveness to CON-RES ewes. CONCLUSION: An increase in placental vessel sensitivity to bradykinin-induced relaxation may contribute to melatonin-induced increases in umbilical artery blood flow.

2011 and 2012 Early Careers Achievement Awards: Placental programming: how the maternal environment can impact placental function.

Proper establishment of the placenta is important for fetal survival; however, placental adaptations to inadequate maternal nutrition or other stressors are imperative for fetal growth to be optimal. The effects of maternal nutritional status and activity level on placental vascular function and uteroplacental blood flows are important to understand as improper placental function leads to reduced growth of the fetus. In environments where fetal growth can be compromised, potential therapeutics may augment placental function and delivery of nutrients to improve offspring performance during postnatal life. Factors that could enhance placental function include supplementation of specific nutrients, such as protein, hormone supplements, such as indolamines, and increased activity levels of the dam. To understand the mechanism of how the maternal environment can impact uterine or umbilical blood flows, assessment of placental vascular reactivity has been studied in several large animal models. As we begin to understand how the maternal environment impacts uterine and umbilical blood flows and other uteroplacental hemodynamic parameters, development of management methods and therapeutics for proper fetal growth can be achieved.