15 research outputs found
Protection, promotion and support of breast-feeding in Europe: progress from 2002 to 2007.
Objective To assess progress in the protection, promotion and support of breast-feeding in Europe. Design Data for 2002 and 2007 were gathered with the same questionnaire. Of thirty countries, twenty-nine returned data for 2002, twenty-four for 2007. Results The number of countries with national policies complying with WHO recommendations increased. In 2007, six countries lacked a national policy, three a national plan, four a national breast-feeding coordinator and committee. Little improvement was reported in pre-service training; however, the number of countries with good coverage in the provision of WHO/UNICEF courses for in-service training increased substantially, as reflected in a parallel increase in the number of Baby Friendly Hospitals and the proportion of births taking place in them. Little improvement was reported as far as implementation of the International Code on Marketing of Breastmilk Substitutes is concerned. Except for Ireland and the UK, where some improvement occurred, no changes were reported on maternity protection. Due to lack of standard methods, it was difficult to compare rates of breast-feeding among countries. With this in mind, slight improvements in the rates of initiation, exclusivity and duration were reported by countries where data at two points in time were available. Conclusions Breast-feeding rates continue to fall short of global recommendations. National policies are improving slowly but are hampered by the lack of action on maternity protection and the International Code. Pre-service training and standard monitoring of breast-feeding rates are the areas where more efforts are needed to accelerate progress
Interconnected Microphysiological Systems for Quantitative Biology and Pharmacology Studies
Microphysiological systems (MPSs) are in vitro models that capture facets of in vivo organ function through use of specialized culture microenvironments, including 3D matrices and microperfusion. Here, we report an approach to co-culture multiple different MPSs linked together physiologically on re-useable, open-system microfluidic platforms that are compatible with the quantitative study of a range of compounds, including lipophilic drugs. We describe three different platform designs - "4-way", "7-way", and "10-way" - each accommodating a mixing chamber and up to 4, 7, or 10 MPSs. Platforms accommodate multiple different MPS flow configurations, each with internal re-circulation to enhance molecular exchange, and feature on-board pneumatically-driven pumps with independently programmable flow rates to provide precise control over both intra- and inter-MPS flow partitioning and drug distribution. We first developed a 4-MPS system, showing accurate prediction of secreted liver protein distribution and 2-week maintenance of phenotypic markers. We then developed 7-MPS and 10-MPS platforms, demonstrating reliable, robust operation and maintenance of MPS phenotypic function for 3 weeks (7-way) and 4 weeks (10-way) of continuous interaction, as well as PK analysis of diclofenac metabolism. This study illustrates several generalizable design and operational principles for implementing multi-MPS "physiome-on-a-chip" approaches in drug discovery.United States. Army Research Office (Grant W911NF-12-2-0039
Decreased efficiency of adenovirus-mediated gene transfer in aging cardiomyocytes.
BACKGROUND: Aging is an independent risk factor for the development of cardiovascular disease. Clinical application of myocardial gene transfer may be best suited in the elderly. In vivo gene transfer by adenovirus is less efficient in aging myocardium. METHODS AND RESULTS: When infected with adenovirus containing beta-galactosidase (beta-gal) and green fluorescent protein (GFP) driven by cytomegalovirus promoters in vitro, aging rat cardiac myocytes exhibit significantly lower infectivity and delayed transgene expression compared with adult controls. Abnormalities of viral internalization may be one mechanism accounting for this difference. To investigate this, we studied expression levels of the coxsackievirus and adenovirus receptor (CAR) as well as other potential integrins involved in the internalization of adenoviruses. CAR expression tended to be upregulated whereas among potential integrins, alpha(3)beta(1) was downregulated in aging cardiac myocytes. Blocking the beta(1) component of alpha(3)beta(1) further decreased infectivity, suggesting that the interaction between the penton base of the adenovirus and beta(1) maybe a crucial component of the viral entry mechanism. CONCLUSIONS: These results suggest that it is integrin-stimulated internalization rather than the adenovirus-CAR interaction that plays a vital role in adenoviral entry. The downregulation of integrins observed in senescent cells may be a key mechanism accounting for the decrease in viral infectivity seen in these cells. These findings have implications for the gene therapy treatment of myocardial failure in the elderly
Β1 Integrins Expression in Adult Rat Ventricular Myocytes and Its Role in the Regulation of β-Adrenergic Receptor-Stimulated Apoptosis
We have shown that the stimulation of β-adrenergic receptors (β-AR) increases apoptosis in adult rat ventricular myocytes (ARVMs). Integrins, a family of αβ-heterodimeric cell surface receptors, are postulated to play a role in ventricular remodeling. Here, we show that norepinephrine (NE) increases β1 integrins expression in ARVMs via the stimulation of α1-AR, not β-AR. Inhibition of ERK1/2 using PD 98059, an inhibitor of ERK1/2 pathway, inhibited α1-AR-stimulated increases in β1 integrins expression. Activation of β1 integrins signaling pathway using laminin (LN) inhibited β-AR-stimulated apoptosis as measured by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL)-staining and flow cytometry. Likewise, ligation of β1 integrins with anti-β1 integrin antibodies prevented β-AR-stimulated apoptosis. Treatment of cells using LN or anti-β1 integrin antibodies activated ERK1/2 pathway. PD 98059 inhibited activation of ERK1/2 by LN, and prevented the anti-apoptotic effects of LN. Thus (1) stimulation of α1-AR regulates β1 integrins expression via the activation of ERK1/2, (2) β1 integrins signaling protects ARVMs from β-AR-stimulated apoptosis, (3) activation of ERK1/2 plays a critical role in the anti-apoptotic effects of β1-integrin signaling. These data suggest that β1 integrin signaling protects ARVMs against β-AR-stimulated apoptosis possibly via the involvement of ERK1/2
Β-Adrenergic Receptor-Stimulated Apoptosis in Cardiac Myocytes Is Mediated by Reactive Oxygen Species/C-Jun NH\u3csub\u3e2\u3c/sub\u3e-Terminal Kinase-Dependent Activation of the Mitochondrial Pathway
Stimulation of β-adrenergic receptors (βARs) causes apoptosis in adult rat ventricular myocytes (ARVMs). The role of reactive oxygen species (ROS) in mediating βAR-stimulated apoptosis is not known. Stimulation of βARs with norepinephrine (10 μmol/L) in the presence of prazosin (100 nmol/L) for 24 hours increased the number of apoptotic myocytes as determined by TUNEL staining by 3.6-fold. The superoxide dismutase/catalase mimetics Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (MnTMPyP; 10 μmol/L) and Euk-134 decreased βAR-stimulated apoptosis by 89±6% and 76±10%, respectively. Infection with an adenovirus expressing catalase decreased βAR-stimulated apoptosis by 82±15%. The mitochondrial permeability transition pore inhibitor bongkrekic acid (50 μmol/L) decreased βAR-stimulated apoptosis by 76±8%, and the caspase inhibitor zVAD-fmk (25 μmol/L) decreased βAR-stimulated apoptosis by 62±11%. βAR-stimulated cytochrome c release was inhibited by MnTMPyP. βAR stimulation caused c-Jun NH2-terminal kinase (JNK) activation, which was abolished by MnTMPyP. Transfection with an adenovirus expressing dominant-negative JNK inhibited βAR-stimulated apoptosis by 81±12%, and the JNK inhibitor SP600125 inhibited both βAR-stimulated apoptosis and cytochrome c release. Thus, βAR-stimulated apoptosis in ARVMs involves ROS/JNK-dependent activation of the mitochondrial death pathway
Protection, promotion and support of breast-feeding in Europe: progress from 2002 to 2007
Redox-mediated reciprocal regulation of SERCA and Na+-Ca2+ exchanger contributes to sarcoplasmic reticulum Ca2+ depletion in cardiac myocytes
Myocardial failure is associated with increased oxidative stress and abnormal excitation-contraction coupling characterized by depletion of sarcoplasmic reticulum (SR) Ca(2+) stores and a reduction in Ca(2+)-transient amplitude. Little is known about the mechanisms whereby oxidative stress affects Ca(2+) handling and contractile function; however, reactive thiols may be involved. We used an in vitro cardiomyocyte system to test the hypothesis that short-term oxidative stress induces SR Ca(2+) depletion via redox-mediated regulation of sarcoendoplasmic reticulum Ca(2+)-ATPase (SERCA) and the sodium-Ca(2+) exchanger (NCX) and that this is associated with thiol oxidation. Adult rat ventricular myocytes paced at 5 Hz were superfused with H(2)O(2) (100 microM, 15 min). H(2)O(2) caused a progressive decrease in cell shortening followed by diastolic arrest, which was associated with decreases in SR Ca(2+) content, systolic [Ca(2+)](i), and Ca(2+)-transient amplitude, but no change in diastolic [Ca(2+)](i). H(2)O(2) caused reciprocal effects on the activities of SERCA (decreased) and NCX (increased). Pretreatment with the NCX inhibitor KB-R7943 before H(2)O(2) increased diastolic [Ca(2+)](i) and mimicked the effect of SERCA inhibition with thapsigargin. These functional effects were associated with oxidative modification of thiols on both SERCA and NCX. In conclusion, redox-mediated SR Ca(2+) depletion involves reciprocal regulation of SERCA and NCX, possibly via direct oxidative modification of both proteins