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.

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.

The interindividual variation in femoral neck width is associated with the acquisition of predictable sets of morphological and tissue-quality traits and differential bone loss patterns.

A better understanding of femoral neck structure and age-related bone loss will benefit research aimed at reducing fracture risk. We used the natural variation in robustness (bone width relative to length) to analyze how adaptive processes covary traits in association with robustness, and whether the variation in robustness affects age-related bone loss patterns. Femoral necks from 49 female cadavers (29-93 years of age) were evaluated for morphological and tissue-level traits using radiography, peripheral quantitative computed tomography, micro-computed tomography, and ash-content analysis. Femoral neck robustness was normally distributed and varied widely with a coefficient of variation of 14.9%. Age-adjusted partial regression analysis revealed significant negative correlations (p < 0.05) between robustness and relative cortical area, cortical tissue-mineral density (Ct.TMD), and trabecular bone mineral density (Ma.BMD). Path analysis confirmed these results showing that a one standard deviation (SD) increase in robustness was associated with a 0.70 SD decrease in RCA, 0.47 SD decrease in Ct.TMD, and 0.43 SD decrease in Ma.BMD. Significantly different bone loss patterns were observed when comparing the most slender and most robust tertiles. Robust femora showed significant negative correlations with age for cortical area (R(2) = 0.29, p < 0.03), Ma.BMD (R(2) = 0.34, p < 0.01), and Ct.TMD (R(2) = 0.4, p < 0.003). However, slender femora did not show these age-related changes (R(2) < 0.09, p > 0.2). The results indicated that slender femora were constructed with a different set of traits compared to robust femora, and that the natural variation in robustness was a determinant of age-related bone loss patterns. Clinical diagnoses and treatments may benefit from a better understanding of these robustness-specific structural and aging patterns.

Tubedown-1 in remodeling of the developing vitreal vasculature in vivo and regulation of capillary outgrowth in vitro.

Tubedown-1 (tbdn-1) is a mammalian homologue of the N-terminal acetyltransferase subunit NAT1 of Saccharomyces cerevisiae and copurifies with an acetyltransferase activity. Tbdn-1 expression in endothelial cells becomes downregulated during the formation of capillary-like structures in vitro and is regulated in vivo in a manner which suggests a functional role in dampening blood vessel development. Here we show that tbdn-1 is expressed highly in the vitreal vascular network (tunica vasculosa lentis and vasa hyaloidea propria) during the pruning and remodeling phases of this transient structure. The vitreal blood vessels of mice harboring a targeted inactivation of TGF-beta2 fail to remodel and abnormally accumulate, a phenomenon reminiscent of the ocular pathology resembling persistent fetal vasculature (PFV) in humans. Since suppression of normal tbdn-1 expression has been previously observed in retinal vessel proliferation, we analyzed vitreal vascular changes and tbdn-1 expression in TGF-beta2(-/-) eyes. The nuclei of vitreal vessel endothelial cells in TGF-beta2(-/-) eyes express proliferating cell nuclear antigen (PCNA) and exhibit increased levels of active (P42/44)mitogen-activated protein kinase (phospho-(P42/44)MAPK), characteristics consistent with proliferative endothelial cells. In contrast to normal vitreal vessels, collagen IV expression exhibited a disorganized pattern in the TGF-beta2(-/-) vitreal vessels, suggesting vessel disorganization and possibly a breakdown of vessel basal laminae. Moreover, vitreal vessels of TGF-beta2(-/-) mice lack expression of pericyte markers (CD13, alpha smooth muscle actin) and show ultrastructural changes consistent with pericyte degeneration. The accumulating vitreal blood vessels of TGF-beta2(-/-) mice, while maintaining expression of the endothelial marker von Willebrand Factor, show a significant decrease in the expression of tbdn-1. We addressed the functional role of tbdn-1 in the regulation of vitreal blood vessels using an in vitro model of choroid-retina capillary outgrowth. Clones of the RF/6A fetal choroid-retina endothelial cell line showing suppression of tbdn-1 levels after overexpression of an antisense TBDN-1 cDNA display a significant increase in the formation of capillary-like structures in vitro compared with controls. These findings suggest that tbdn-1 inhibits capillary-like formation in vitro and may serve to dampen vitreal blood vessel formation preceding the regression of the vitreal vasculature during development. Our results also suggest that tbdn-1 may participate with TGF-beta2 in regulating normal development of the vitreal vasculature.

Retinopathy of prematurity.

The majority of cases of ROP regress spontaneously, but better treatment methods are needed to prevent retinal detachment and other effects of ROP such as myopia. In the future, molecular mechanisms may be exploited to treat ROP.

Suppressed expression of tubedown-1 in retinal neovascularization of proliferative diabetic retinopathy.

PURPOSE: Retinal neovascularization occurring as a complication of diabetes mellitus can cause vision loss and blindness. The identification and study of novel genes involved in retinal angiogenesis may define new targets to suppress retinal neovascularization in diabetes and other ocular diseases. A novel acetyltransferase subunit, tubedown-1 (tbdn-1), has been isolated, the expression of which is regulated during blood vessel development. Tbdn-1 is not detected in most adult vascular beds but persists at high levels in the adult ocular vasculature. The purpose of this study was to gain insight into the possible role of tbdn-1 in retinal blood vessels by characterizing its expression patterns in adult homeostasis and in retinal neovascularization associated with diabetes. METHODS: Western blot analysis and immunohistochemistry were performed to study the expression patterns of tbdn-1 during adult homeostasis in normal human retinas, in a model of choroid-retina endothelial capillary outgrowth in vitro, and in retinas showing neovascularization in patients with proliferative diabetic retinopathy (PDR). RESULTS: In adults during homeostasis, tbdn-1 was expressed highly in normal endothelium of retinal and limbic blood vessels. Tbdn-1 was also expressed in RF/6A, a rhesus macaque choroid-retina-derived endothelial cell line. In an in vitro model system using the RF/6A cell line, tbdn-1 expression was downregulated during the outgrowth of these cells into capillary-like structures on a reconstituted basement membrane matrix. Similar to this in vitro model, tbdn-1 expression is specifically suppressed in the endothelial cells of blood vessels and capillary fronds in vivo in both the neural retinal tissue and in preretinal membranes in eyes of patients with PDR. CONCLUSIONS: High levels of expression of tbdn-1 are associated with ocular endothelial homeostasis in adults. Conversely, low levels of tbdn-1 expression are associated with endothelial capillary outgrowth in vitro and retinal neovascularization in vivo. Because the tbdn-1 acetyltransferase subunit is a member of a family of regulatory enzymes that are known to control a range of processes, including cell growth and differentiation, through posttranslational modification, the current results support a hypothesis that tbdn-1 may be involved in maintaining homeostasis and preventing retinal neovascularization.

MK/T-1, an immortalized fibroblast cell line derived using cultures of mouse corneal stroma.

PURPOSE: Immortalized cell lines representing fibroblast cells from corneal stroma would facilitate studies of corneal cell biology and injury response. METHODS: Primary cultures of cells derived from mouse corneal stroma were transfected with a human telomerase reverse transcriptase (hTERT) expression construct to maximize chances of cellular immortalization. A resulting cell line was analyzed for telomerase activity, cell growth characteristics, senescence and gene expression patterns. Specific responses to transforming growth factor beta (TGF-beta) were also analyzed. RESULTS: An immortalized cell line was derived and was named MK/T-1. MK/T-1 cells show no signs of cellular senescence or transformation at over 100 passages. Telomerase activity was significantly higher in MK/T-1 cells as compared to the parental cell cultures. However, relative telomere length (RTL) in the MK/T-1 and parental cells was not significantly different. Senescence associated beta-galactosidase (SA-beta-Gal) activity was not detected in late passage MK/T-1 cells while the parental cells had already upregulated SA-beta-Gal at high levels by passage 9. The MK/T-1 cells express vimentin, tubulin, lumican, mimecan, decorin and collagen I, but not keratocan. Exposure of the MK/T-1 cells to TGF-beta induces the expression of smooth muscle alpha-actin (ASMA), the activation of MAP Kinase (p38-MAPK) and morphological changes consistent with cytoskeletal reorganization. CONCLUSIONS: MK/T-1 cells represent an immortalized fibroblast cell line derived using cultures from corneal stroma cell preparations. Expression of hTERT may contribute to immortalization of the MK/T-1 cells by a mechanism other than increases in RTL. MK/T-1 cells may be a useful model in which to study the responses of corneal fibroblast cells to cytokines and other diverse environmental factors in vitro.

TGFbeta2 in corneal morphogenesis during mouse embryonic development.

To examine the roles of TGFbeta isoforms on corneal morphogenesis, the eyes of mice that lack TGFbetas were analyzed at different developmental stages for cell proliferation, migration and apoptosis, and for expression patterns of keratin 12, lumican, keratocan and collagen I. Among the three Tgfb(-/-) mice, only Tgfb2(-/-) mice have abnormal ocular morphogenesis characterized by thin corneal stroma, absence of corneal endothelium, fusion of cornea to lens (a Peters'-like anomaly phenotype), and accumulation of hyaline cells in vitreous. In Tgfb2(-/-) mice, fewer keratocytes were found in stroma that has a decreased accumulation of ECM; for example, lumican, keratocan and collagen I were greatly diminished. The absence of TGFbeta2 did not compromise cell proliferation, nor enhance apoptosis. The thinner stroma resulting from decreased ECM synthesis may account for the decreased cell number in the stroma of Tgfb2 null mice. Keratin 12 expression was not altered in Tgfb2(-/-) mice, implicating normal corneal type epithelial differentiation. Delayed appearance of macrophages in ocular tissues was observed in Tgfb2(-/-) mice. Malfunctioning macrophages may account for accumulation of cell mass in vitreous of Tgfb2 null mice.

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.

LIF transduces contradictory signals on capillary outgrowth through induction of stat3 and (P41/43)MAP kinase.

The signaling pathways regulating blood vessel growth and development are not well understood. In the present report, an in vitro model was used to identify signaling pathways regulating capillary formation in embryonic endothelial cells. Basic fibroblast growth factor (bFGF) plus leukemia inhibitory factor (LIF) optimally stimulate the formation of capillary-like structures of the embryonic endothelial cell line IEM. LIF stimulation of IEM cells leads to activation of the Stat3 as well as the (P41/43)mitogen-activated protein kinase ((P41/43)MAPK) cascade, while bFGF does not activate Stat3 but does induce the (P41/43)MAPK cascade. Inhibition of Stat3 DNA-binding activity by expression of a dominant inhibitory Stat3 mutant increases the capillary outgrowth of the IEM cells induced by LIF. Increased Stat3 activity by overexpression of the wild-type Stat3 greatly reduced capillary outgrowth. In contrast, inhibition of the (P41/43)MAPK cascade using a MEK-1 inhibitor dramatically inhibits the LIF-induced capillary outgrowth. Moreover, the increased formation of capillary-like structures of the IEM cells mediated by Stat3 inhibition does not overcome the requirement for activation of the (P41/43)MAPK pathway for capillary outgrowth. Stat3 activity correlates with the LIF-induced expression of the negative feedback regulators of the Janus (JAK) family of tyrosine kinases, SOCS-1 and SOCS-3. These results provide evidence that Stat3 acts as a negative regulator of capillary outgrowth, possibly by increasing SOCS-1 or SOCS-3 expression. The contradictory signals stimulated by LIF could be necessary to control the intensity of the response leading to capillary outgrowth in vivo.

Outpatient cervical ripening with intravaginal misoprostol.

OBJECTIVE: To determine if outpatient cervical ripening using misoprostol can initiate labor within 48 hours of medication administration and to determine if time from medication administration to time of delivery is decreased using outpatient cervical ripening. METHODS: Uncomplicated singleton, vertex pregnancies at 41 weeks' gestation or later with Bishop score of 4 or less were eligible for enrollment. Other inclusion criteria included intact membranes, less than eight uterine contractions per hour, a reactive nonstress test, and amniotic fluid index (AFI) over 5 cm. After randomization, 25 micro(cg) of misoprostol or placebo was placed within the posterior vaginal fornix. Patients were continuously monitored for 4 hours, then discharged if not in active labor. Patients returned in 24 hours for a repeat administration of the respective medication. Patients not delivered within 48 hours were admitted for inpatient induction of labor. Statistical analysis was performed with the Fisher, Student t, chi(2), and Mann-Whitney U tests, with P <.05 considered statistically significant. RESULTS: Among the 60 patients enrolled, 27 (45%) received misoprostol and 33 (55%) received placebo. The majority (24 of 27, 88.9%) of study group patients entered active labor within 48 hours after dosing, compared with 16.7% (five of 33) of placebo group patients (P <.001). The time from initial dose to delivery was significantly shorter in the misoprostol group (36.9 +/- 3.8 compared with 61.3 +/- 3.8 hours, P <.001). CONCLUSION: Intravaginal misoprostol is effective for outpatient cervical ripening. No adverse effects were encountered, although further study is required to determine the safety of this treatment regimen.

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.

Tubedown-1, a novel acetyltransferase associated with blood vessel development.

We have used an embryonic endothelial cell line (IEM cells) as an experimental system for identifying and characterizing new molecules which are regulated during blood vessel development. A novel gene isolated from IEM cells, tubedown-1 (tbdn-1), is expressed at high levels in unstimulated IEM cells and is downregulated during formation of capillary tube structures by the IEM cells induced by basic fibroblast growth factor (bFGF) and leukemia inhibitory factor (LIF) in vitro. Tbdn-1 is also downregulated in M1 myeloid leukemia cells after differentiation in response to LIF in vitro. Tbdn-1 is homologous to the yeast NAT-1 N-terminal acetyltransferases and encodes a novel protein of approximately 69 kDa associated with an acetyltransferase activity. Levels and distribution of tbdn-1 expression are regulated in both endothelial and hematopoietic cells during development in tissues such as the yolk sac blood islands, heart, and liver blood vessels. In the adult, tbdn-1 expression is low or undetected in most organs examined with the exception of the atrial endocardium, the endothelial and myeloid compartments of bone marrow, and the remodeling vascular bed of atretic ovarian follicles. The distribution and regulation of expression of tbdn-1 suggest that this novel acetyltransferase may be involved in regulating vascular and hematopoietic development and physiologic angiogenesis.

Embryonic vasculogenesis by endothelial precursor cells derived from lung mesenchyme.

During development, the lung mesenchyme has a dynamic relationship with the branching airway. Embryonic lung mesenchyme is loosely packed and composed of indistinguishable cells, yet it is the source of vascular progenitors that will become endothelial cells, smooth muscle cells and fibroblasts. In the lung, vessel development in the periphery proceeds first through vasculogenesis, the migration and assembly of cells into a primitive network, and subsequently, through angiogenesis, the sprouting of vessels from this network. As a way to assess the cellular and molecular mechanisms of lung vascularization, we have isolated and cloned cell lines from mouse fetal lung mesenchyme (MFLM). Two of these MFLM cell lines, MFLM-4 and MFLM-91U, display characteristics of an endothelial lineage. RNA analysis demonstrates transcripts for the vascular endothelial growth factor receptors R1 and R2, the receptor tyrosine kinases, Tie-1 and Tie-2, as well as the Tie-2 ligands, Ang-1 and -2. The MFLM cell lines form extensive networks of capillary-like structures with lumens when cultured on a reconstituted basement membrane. In vivo, following blastocyst injection, the MFLM cells chimerize endothelium of the lung and areas of the heart vasculature. The results from these studies suggest that MFLM-4 and MFLM-91U, derived from embryonic lung mesenchyme, can function in vitro and in vivo as endothelial precursors and as models of cardiopulmonary vascularization. Dev Dyn 2000;217:11-23.

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.