Coronary and Systemic Vasodilator Responsiveness of Patients Receiving Conventional Intermittent or Nocturnal Hemodialysis.

BACKGROUND: Nocturnal hemodialysis (nHD) restores the attenuated brachial artery vasodilator responsiveness of patients receiving conventional intermittent hemodialysis (iHD). Its impact on coronary vasodilatation is unknown. METHODS: We evaluated 25 patients on hemodialysis who fulfilled transplant criteria: 15 on iHD (4-hour sessions, 3 d/wk) and 10 on nHD (≈40 h/wk over 8-10-hour sessions) plus 6 control participants. Following diagnostic angiography, left anterior descending (LAD) coronary flow reserve and mean luminal diameter were quantified at baseline and during sequential intracoronary administration of adenosine (infusion and bolus), nitroglycerin (bolus), acetylcholine (infusion), acetylcholine coinfused with vitamin C, and, finally, sublingual nitroglycerin. RESULTS: Coronary flow reserve in those receiving nHD was augmented relative to iHD (3.28±0.26 versus 2.17±0.12 [mean±SEM]; P<0.03) but attenuated, relative to controls (4.80±0.63; P=0.011). Luminal dilatations induced by intracoronary adenosine and nitroglycerin were similar in nHD and controls but blunted in the iHD cohort (P<0.05 versus both). ACh elicited vasodilatation in controls but constriction in both dialysis groups (both P<0.05, versus control); vitamin C coinfusion had no effect. Sublingual nitroglycerin increased mid-left anterior descending diameter and reduced mean arterial pressure in controls (+15.2±2.68%; -16.00±1.60%) and in nHD recipients (+14.78±5.46%; -15.82±1.32%); iHD responses were markedly attenuated (+1.9±0.86%; -5.89±1.41%; P<0.05, all comparisons). CONCLUSIONS: Coronary and systemic vasodilator responsiveness to both adenosine and nitroglycerin is augmented in patients receiving nHD relative to those receiving iHD, whereas vasoconstrictor responsiveness to acetylcholine does not differ. By improving coronary conduit and microvascular function, nHD may reduce the cardiovascular risk of patients on dialysis.

Phenotypes of maternal vascular malperfusion placental pathology and adverse pregnancy outcomes: A retrospective cohort study.

OBJECTIVE: To identify which components of maternal vascular malperfusion (MVM) pathology are associated with adverse pregnancy outcomes and to investigate the morphological phenotypes of MVM placental pathology and their relationship with distinct clinical presentations of pre-eclampsia and/or fetal growth restriction (FGR). DESIGN: Retrospective cohort study. SETTING: Tertiary care hospital in Toronto, Canada. POPULATION: Pregnant individuals with low circulating maternal placental growth factor (PlGF) levels (<100 pg/mL) and placental pathology analysis between March 2017 and December 2019. METHODS: Association between each pathological finding and the outcomes of interest were calculated using the chi-square test. Cluster analysis and logistic regression was used to identify phenotypic clusters, and their association with adverse pregnancy outcomes. Cluster analysis was performed using the K-modes unsupervised clustering algorithm. MAIN OUTCOME MEASURES: Preterm delivery <34+0 weeks of gestation, early onset pre-eclampsia with delivery <34+0 weeks of gestation, birthweight <10th percentile (small for gestational age, SGA) and stillbirth. RESULTS: The diagnostic features of MVM most strongly associated with delivery <34+0 weeks of gestation were: infarction, accelerated villous maturation, distal villous hypoplasia and decidual vasculopathy. Two dominant phenotypic clusters of MVM pathology were identified. The largest cluster (n = 104) was characterised by both reduced placental mass and hypoxic ischaemic injury (infarction and accelerated villous maturation), and was associated with combined pre-eclampsia and SGA. The second dominant cluster (n = 59) was characterised by infarction and accelerated villous maturation alone, and was associated with pre-eclampsia and average birthweight for gestational age. CONCLUSIONS: Patients with placental MVM disease are at high risk of pre-eclampsia and FGR, and distinct pathological findings correlate with different clinical phenotypes, suggestive of distinct subtypes of MVM disease.

The Placental Basis of Fetal Growth Restriction.

Placental dysfunction is a major contributing factor to fetal growth restriction. Placenta-mediated fetal growth restriction occurs through chronic fetal hypoxia owing to poor placental perfusion through a variety of mechanisms. Maternal vascular malperfusion is the most common placental disease contributing to fetal growth restriction; however, the role of rare placental diseases should not be overlooked. Although the features of maternal vascular malperfusion are identifiable on placental pathology, antepartum diagnostic methods are evolving. Placental imaging and uterine artery Doppler, used in conjunction with angiogenic growth factors (specifically placenta growth factor and soluble fms-like tyrosine kinase-1), play an increasingly important role.

Barriers to Treatment of Tinea Capitis in Children Living in the Jane Finch Community of Toronto.

BACKGROUND: Tinea capitis is a common fungal infection of the scalp. If left untreated, tinea capitis infection can cause severe inflammatory reactions and the development of kerion. Tinea capitis is effectively treated with oral antifungals, but at present these are not covered under government assistance programs. OBJECTIVE: To assess the potential impact of a limited use code for antifungal therapy in the treatment of childhood tinea capitis. METHOD: Fourteen family physicians practicing in the Jane Finch area were surveyed on their experience treating tinea capitis in this community. RESULTS: Seventy-one percent of surveyed family physicians felt that cost impedes the treatment of tinea capitis in their practice, and 100% felt that a limited use code would have a positive impact on their patients. CONCLUSION: A limited use code for oral antifungal treatments of tinea capitis may provide a simple, cost-effective solution to a major problem impacting children in the Jane Finch area.

Pityriasis rotunda diagnosed in Canada: case presentation and review of the literature.

BACKGROUND: Pityriasis rotunda is a rare cutaneous disorder characterized by scaly, circular, well-demarcated, hypo- or hyperpigmented, fine plaques over the trunk and extremities. OBJECTIVE: We present a case of pityriasis rotunda in a 44-year-old African-Canadian woman who presented to a community dermatology practice in Toronto. RESULTS: Pityriasis rotunda has been well described in Japan, Italy, and South Africa. It is extremely rare in North America, with nine reported cases to date, the majority of which were diagnosed in the United States. CONCLUSION: Pityriasis rotunda is a rare cutaneous disorder associated with systemic disease. To the best of our knowledge, this is the second report of pityriasis rotunda diagnosed in Canada.