Prenatal diagnosis and prognosis of accelerated idioventricular rhythm

OBJECTIVES

As postnatal identification of accelerated idioventricular rhythm (AIVR) relies on specific electrocardiographic patterns, prenatal diagnosis of this condition is challenging and its true incidence is unknown. The objectives of this study were to evaluate the performance of prenatal ultrasonography in identifying intrauterine cardiocirculatory events linked to specific electrocardiographic signs of postnatal AIVR, including left or right ventricular origin, and to assess the prenatal prognosis of this arrhythmia.

METHODS

We reviewed Doppler tracings from the superior vena cava/ascending aorta (SVC/Ao), ductus venosus (DV), ductus arteriosus (DA) and aortic isthmus (AoI), as well as simultaneous M-mode recordings of septal and left ventricular wall motions of fetuses diagnosed with AIVR from January 2004 to December 2014.

RESULTS

Three cases of AIVR were identified among 27 912 fetuses. SVC/Ao Doppler flow recordings revealed atrioventricular dissociation (ventricular rates within 20% of atrial rates) in all three fetuses and episodes of isorhythmic atrioventricular dissociation in one, while M-mode confirmed normal left ventricular shortening fraction in all cases. Fusion beats were observed on AoI tracing in one fetus, while simultaneous recordings of AoI and DA revealed signs of right bundle branch block in one case and left bundle branch block in the other two. On DV Doppler recordings, retrograde a-waves in the presence of simultaneous atrial and ventricular contractions were observed in all three fetuses, leading to an increase in central venous pressure in all and hydrops fetalis in two cases without evidence of ventricular dysfunction.

CONCLUSIONS

Echocardiographic criteria required for postnatal diagnosis of AIVR can be documented in utero using specific ultrasonographic approaches. During fetal life, AIVR may not be a benign entity. Hydrops fetalis is frequently associated with AIVR because of increase in central venous pressure related to simultaneous atrioventricular contractions; thus, the ultrasonographic investigation protocol of fetuses with unexplained hydrops fetalis should aim at ruling out AIVR and include Doppler flow recordings in SVC/Ao, DV, AoI, DA and umbilical vein. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Aortic Isthmus Flow Recording Predicts the Outcome of the Recipient Twin after Laser Coagulation in Twin-Twin Transfusion Syndrome

INTRODUCTION

The objective was to assess the prognostic value of the systolic flow through the aortic isthmus in monochorionic pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated by placental laser ablation.

MATERIAL AND METHODS

Fetal echocardiography and outcome data of 105 cases of TTTS treated by laser photocoagulation of placental anastomoses were reviewed. Hemodynamic parameters were collected before and after treatment. The isthmic systolic index (ISI) was calculated as the peak systolic velocity/systolic nadir ratio.

RESULTS

A total of 105 laser coagulations were studied. Fetal echocardiography pre- and post-laser were available in 68 cases, including 55 with data on aortic isthmic Doppler. Survival rates were 17, 22, and 61% for 0, 1, or 2 twins, respectively. At least 1 twin was delivered alive in 83% of the pregnancies. The mean gestational age at surgery was 21 weeks (range 16-26). Median ISI values were similar for donor and recipient twins, before and after laser ablation (all p > 0.05). A lower recipient ISI before laser was related to early recipient demise within 24 h (p = 0.04).

DISCUSSION

A lower ISI before placental laser ablation for TTTS is associated with postoperative demise of the recipient twin.

Profiling left and right ventricular proportional output during fetal life with a novel systolic index in the aortic isthmus

OBJECTIVE

Left ventricular ejection causes forward flow in the fetal aortic isthmus while the right ventricle has a retrograde influence. The aim of this study was to create reference values for an isthmic systolic index (ISI) reflecting the changing influence of right and left ventricular performance on Doppler flow velocity waveforms of the aortic isthmus throughout normal pregnancy.

METHODS

Doppler recordings of 260 normal fetuses with a gestational age of 18-37 weeks were reviewed. Peak systolic velocity (PSV) and end-systolic velocity (or systolic nadir; Ns) were measured on all aortic isthmus waveforms. An ISI was derived from the ratio Ns/PSV. Left and right ventricular outputs were also calculated.

RESULTS

Up to 22-23 weeks' gestation, the mean ISI is stable at around 0.2. At about 28 weeks, a brief end-systolic deceleration wave is observed on the aortic isthmus waveforms, progressing steadily with gestation and causing a fall of ISI towards a mean value of zero between 30 and 31 weeks. This trend continues thereafter and a mean value of -0.4 was observed at the end of pregnancy. An inverse correlation was found between right ventricular output and Ns (r = -0.334, P = 0.001). Simultaneous recordings of the isthmus and the ductus arteriosus Doppler waveforms demonstrated that the primary cause of the end-systolic deceleration and ultimate reversal of flow at the isthmus is the increasingly dominant flow from the right ventricle.

CONCLUSION

The transitional changes of the respective right and left ventricular outputs throughout pregnancy are well profiled by the ISI. This index highlights the physiological increase in fetal right ventricle flow preponderance as pregnancy progresses. Alteration of the ISI profile could be expected in clinical conditions associated with unbalanced alteration of the fetal ventricular outputs.

Age-dependent recombination rates in human pedigrees

In humans, chromosome-number abnormalities have been associated with altered recombination and increased maternal age. Therefore, age-related effects on recombination are of major importance, especially in relation to the mechanisms involved in human trisomies. Here, we examine the relationship between maternal age and recombination rate in humans. We localized crossovers at high resolution by using over 600,000 markers genotyped in a panel of 69 French-Canadian pedigrees, revealing recombination events in 195 maternal meioses. Overall, we observed the general patterns of variation in fine-scale recombination rates previously reported in humans. However, we make the first observation of a significant decrease in recombination rates with advancing maternal age in humans, likely driven by chromosome-specific effects. The effect appears to be localized in the middle section of chromosomal arms and near subtelomeric regions. We postulate that, for some chromosomes, protection against non-disjunction provided by recombination becomes less efficient with advancing maternal age, which can be partly responsible for the higher rates of aneuploidy in older women. We propose a model that reconciles our findings with reported associations between maternal age and recombination in cases of trisomies.

A phase II, open-label study of the efficacy and safety of imiquimod in the treatment of superficial and mixed infantile hemangioma

OBJECTIVES

To explore the efficacy and safety of imiquimod 5% cream as a treatment for infantile hemangioma.

DESIGN

Phase II, open-label, noncomparative study of imiquimod applied during 16 weeks, with posttherapy follow-up 16 weeks later (8 months total).

SETTING

Outpatient pediatric tertiary care referral center in Quebec, Canada.

PARTICIPANTS

Healthy infants up to 8.8 months of age with previously untreated, nonulcerated, proliferative superficial or mixed infantile hemangioma, excluding periorbital, or perineal localization, > or =100 cm2 in size.

INTERVENTION

Topical imiquimod applied three to seven times per week for 16 weeks to infantile hemangioma.

MAIN OUTCOME MEASURES

Lesion area, volume, depth (Doppler ultrasound), and color (erythema), serum drug, and interferon-alpha levels.

RESULTS

Sixteen infants (11 girls, 5 boys) with a mean age at entry of 4.1 months and mean lesion area of 32.89 cm2, and volume of 39.98 cm3 were enrolled. Two participants discontinued treatment early, one for an adverse event (crying upon application), the other because of the lack of compliance. Local skin reactions were consistent with those reported in adults. Two cases had a decrease and three had an increase in lesion parameters; otherwise no meaningful changes in lesion area, volume, or depth were observed. At the 4-month posttreatment visit, 11 of 14 subjects had improvement in erythema (marginal homogeneity test = 2.668, p = 0.008). Measured serum drug and interferon-alpha levels were low or undetectable.

CONCLUSIONS

Treatment of infants with infantile hemangioma with imiquimod up to seven times per week for 16 weeks was generally well tolerated with low systemic exposure. Improvement was observed in hemangioma coloration, but not lesion size, suggesting effects were limited to the superficial component.

Cytokine tissue levels as markers of disease activity in pediatric Crohn disease

The mucosal immune system is overactivated in Crohn disease (CD) and viral infections have been associated with clinical exacerbations. To investigate the potential association between mucosal inflammation and the cytokines involved in the early response to viruses, we analyzed colonic tissue levels of IL-2Ralpha, interferon-alpha, and IL-15 in CD. Patients undergoing diagnostic colonoscopy were classified into controls (n = 22) and three CD groups based on the histologic severity of inflammation and clinical activity: a) severely active CD (n = 3); b) mild to moderately active CD (n = 14); and c) quiescent CD (n = 23). Rectal biopsies (two per patient) were homogenized and cytokine levels determined by ELISA kits. Statistical analysis was performed by ANOVA with Tukey and Scheffé tests. IL-2Ralpha levels were increased in the active CD group compared with the quiescent CD group: a) 405 +/- 87, b) 159 +/- 31, and c) 33 +/- 15 pg/mg DNA (p < 0.001). The latter group was similar to controls (39 +/- 20 pg/mg DNA). Furthermore, a linear correlation (r = 0.98) between IL-2Ralpha and disease activity (Van Hees index) was observed. IL-15 levels were also higher in active compared with quiescent CD and controls: a) 0.69 +/- 0.23 and b) 0.72 +/- 0.31 versus c) 0.28 +/- 0.21 and 0.28 +/- 0.14 pg/mg DNA for controls (p < 0.05). Interferon-alpha levels were undetectable in all samples. Our data suggest that IL-2Ralpha tissue levels correlate with CD activity. IL-15 is also overproduced in inflamed CD tissue. The lack of a parallel elevation of interferon-alpha does not support a role for viral induction of IL-15 in inflamed CD samples.

Impressions of breastfeeding information and support among first-time mothers within a multiethnic community

The purpose of this study was to document mothers' perceptions of breastfeeding information and support received from hospital- and community-based health professionals within a multiethnic community. A telephone survey was conducted to assess: mothers' impressions of professional support for breastfeeding, whether recommended breastfeeding practices were followed by health professionals, and the nature and sources of breastfeeding information received. An ethnically diverse sample of 108 first-time breastfeeding mothers was surveyed at 3 weeks postpartum. Overall, the mothers' evaluations of professional support for breastfeeding were positive, even though they reported breastfeeding practices that fell short of recommended standards. Immigrant mothers were found more likely to experience hospital practices detrimental to breastfeeding success than Canadian-born mothers, but were also found more likely to receive professional breastfeeding support in the community. Significant differences were also found between immigrant and Canadian-born mothers in the sources of their breastfeeding information. The findings underscore the key role of nurses in ensuring the promotion and optimal support of breastfeeding.

The oral cavity as a reservoir of bacterial pathogens for focal infections

Dental procedures, but more importantly, oral infections and poor oral health can provoke the introduction of oral microorganisms into the bloodstream or the lymphatic system. The subsequent attachment and multiplication of these bacteria on tissues or organs can lead to focal oral infections. Pathogenic agents may also remain at their primary oral site but the toxins liberated can reach an organ or tissue via the bloodstream and cause metastatic injury. Finally, metastatic inflammation may result from an immunological injury caused by oral bacteria or their soluble products that enter the bloodstream and react with circulating specific antibodies to form macromolecular complexes.

Inhibition of the activities of matrix metalloproteinases 2, 8, and 9 by chlorhexidine

Matrix metalloproteinases (MMPs) are a host cell-derived proteolytic enzyme family which plays a major role in tissue-destructive inflammatory diseases such as periodontitis. The aim of the present study was to evaluate the inhibitory effect of chlorhexidine (CHX) on MMP-2 (gelatinase A), MMP-9 (gelatinase B), and MMP-8 (collagenase 2) activity. Heat-denatured type I collagen (gelatin) was incubated with pure human MMP-2 or -9 activated with p-aminophenylmercuric acetate (APMA), and the proteolytic degradation of gelatin was monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Coomassie blue staining. The effect of CHX on MMP-8 activity was also studied with a cellular model addressing the ability of phorbol myristate acetate (PMA)-triggered human peripheral blood neutrophils (polymorphonuclear leukocytes [PMNs]) to degrade native type I collagen. CHX inhibited the activities of both gelatinases (A and B), but MMP-2 appeared to be more sensitive than MMP-9. Adding calcium chloride to the assay mixtures almost completely prevented the inhibition of MMP-9 activity by CHX, while the inhibition of MMP-2 activity could be reversed only when CHX was used at a low concentration. This observation suggests that CHX may act via a cation-chelating mechanism. CHX dose-dependently inhibited collagenolytic activity of MMP-8 released by PMA-triggered PMNs. MMP-8 without APMA activation was inhibited clearly more efficiently than APMA-activated MMP-8. Our study suggests that the direct inhibition of the MMPs' activities by CHX may represent a new valuable effect of this antimicrobial agent and explains, at least in part, the beneficial effects of CHX in the treatment of periodontitis.

Effect of microbial siderophores on matrix metalloproteinase-2 activity

Matrix metalloproteinases (MMPs) are capable of cleaving almost all macromolecules of the extracellular connective tissue matrix and are thought to play a major role in tissue destructive inflammatory diseases such as periodontitis. The aim of this study was to determine the effects of siderophores, which are iron-chelating molecules produced by a variety of microorganisms, on the activity of MMP-2. Heat-denatured type I collagen (gelatin) was incubated with p-aminophenylmercuric acetate-activated MMP-2 and siderophores. Degradation of gelatin was monitored by SDS-PAGE and Coomassie blue staining. Ferrichrome, rhodotorulic acid, desferoxamine mesylate and 2,3-dihydroxybenzoic acid were found to inhibit the MMP-2 activity whereas beta-phenylpyruvic acid had no effect. The inhibition could be reversed by adding an excess calcium chloride or ferric chloride to the assay mixtures. Our study suggests that microbial siderophores may represent new-potential therapeutic molecules for the treatment of destructive inflammatory diseases involving excess MMP-2 activity, such as periodontitis.

Regulated pre-employment medical examinations and their effect on the utilization of health services: the experience of 1,498 police cadets, Quebec, 1988

Persons seeking employment in a police department must submit to a pre-induction medical screening after they have qualified on a compulsory test of physical stamina. The effect of this imposition on the utilization of health services was studied in a group of 1,498 police cadets whose use of medical and optometric services was monitored over a period of one year and compared with that of the general population of the same age and sex. Cadets have used about as much care as women of child-bearing age and were almost all exposed to physiological and radiological procedures that have no known utility in the medical surveillance of workers. It is estimated that the cost of providing the protection that is apparently sought by the regulation varies between $6,285 and $66,000 per person.

Trisomy 15 with loss of the paternal 15 as a cause of Prader-Willi syndrome due to maternal disomy

Uniparental disomy has recently been recognized to cause human disorders, including Prader-Willi syndrome (PWS). We describe a particularly instructive case which raises important issues concerning the mechanisms producing uniparental disomy and whose evaluation provides evidence that trisomy may precede uniparental disomy in a fetus. Chorionic villus sampling performed for advanced maternal age revealed trisomy 15 in all direct and cultured cells, though the fetus appeared normal. Chromosome analysis of amniocytes obtained at 15 wk was normal in over 100 cells studied. The child was hypotonic at birth, and high-resolution banding failed to reveal the deletion of 15q11-13, a deletion which is found in 50%-70% of patients with PWS. Over time, typical features of PWS developed. Molecular genetic analysis using probes for chromosome 15 revealed maternal disomy. Maternal nondisjunction with fertilization of a disomic egg by a normal sperm, followed by loss of the paternal 15, is a likely cause of confined placental mosaicism and uniparental disomy in this case of PWS, and advanced maternal age may be a predisposing factor.