Expression of cytochromes P450 4F4 and 4F5 in infection and injury models of inflammation.

Lipopolysaccharide (LPS) treatment of rats suppresses CYP 4F4 and 4F5 expression by 50 and 40%, respectively, in a direct fashion occurring in the liver. This contention is borne out by essentially parallel dose-dependent changes observed upon treatment of rat hepatocyte cultures with LPS. An alternate avenue of triggering the inflammatory cascade is traumatic brain injury by controlled cortical impact. Such injury brings about a dramatic change in the expression of CYP 4F4 and 4F5 mRNA which reaches its greatest effect 24 h after impact compared with sham-operated but uninjured controls. At time points after 24 h the expression of both isoforms increases dramatically reaching highest levels at 2 weeks post-injury. These changes in mRNA expression are mirrored by changes in protein expression. The results are consistent with the notion that immediately after injury concentrations of leukotriene and prostaglandin mediators are elevated by decreased CYP 4F concentrations. As time after injury increases those conditions reverse. Increased CYP 4F expression leads to diminished concentrations of leukotriene and prostaglandin mediators and then to recovery and repair.

Evidence that Galpha(q)-coupled receptor-induced interleukin-6 mRNA in vascular smooth muscle cells involves the nuclear factor of activated T cells.

The immunosuppressant cyclosporin A inhibits transcription mediated by the nuclear factor of activated T-cells (NFAT), a key regulator of cytokine gene expression in lymphocytes that integrates phospholipase C signaling. NFAT is also expressed in vascular smooth muscle cells, but the genes it regulates there are unknown. Here we show that Galpha(q)-coupled P2Y nucleotide receptor signaling in rat vascular smooth muscle cells increases NFAT-mediated luciferase reporter expression. It also induces interleukin (IL)-6 gene expression but not other cytokine mRNAs including IL-1, IL-2, IL-3, IL-4, IL-10, gamma-interferon, tumor necrosis factor-alpha, or tumor necrosis factor-beta. IL-6 mRNA induction by UTP is more rapid and transient then that caused by IL-1beta stimulation and is partially blocked by cyclosporin A or by expression of a trans-dominant NFAT inhibitor. Expression of recombinant NFATc1 markedly augments IL-6 mRNA induction by these and other agonists, which is partially attributable to NFAT-regulated paracrine mediators. However, trans-dominant NFkappaB inhibitors strongly interfere with IL-6 mRNA induction both by IL-1beta and by UTP, which synergistically evoke IL-6 mRNA expression. These findings suggest that NFAT is among the cofactors involved in NFkappaB-dependent IL-6 gene induction by Ca(2+)-mobilizing receptors in vascular smooth muscle cells.

Cyclosporin A selectively inhibits mitogen-induced cyclooxygenase-2 gene transcription in vascular smooth muscle cells.

The prostaglandin synthase cyclooxygenase-2 (COX-2) is produced by an immediate early response gene induced in most cells by a variety of stimuli. Several studies have shown that the immunosuppressant cyclosporin (CsA) interferes with prostanoid metabolism, but the mechanisms are unclear. Here we examine the effect of CsA on COX-2 mRNA induction in cultured rat vascular smooth muscle cells (VSMC) that natively express the nuclear factor of activated T-cells, a known mediator of CsA-sensitive transcription. CsA significantly suppresses strong COX-2 mRNA induction caused by the Ca(2+)-mobilizing mitogens UTP, angiotensin II, and platelet-derived growth factor-BB, and the synergistic induction caused by costimulation with ionomycin and a phorbol ester. Forskolin and interleukin-1beta are substantially weaker COX-2 mRNA inducers, and CsA does not inhibit their effect. CsA strongly inhibits UTP-, angiotensin II-, and platelet-derived growth factor-BB-stimulated COX-2 gene transcription as measured by nuclear run-on or promoter-reporter studies, but has no effect on mRNA induction caused by post-transcriptional stabilization of a distal COX-2 mRNA 3'-untranslated region regulatory element. These data show that CsA selectively inhibits mitogen-induced COX-2 gene expression by a transcriptional mechanism that may involve the nuclear factor of activated T-cells.

Iatrogenic main pulmonary artery-left atrial fistula in a child.

A 14-month-old boy who underwent operation for ventricular septal defect patch closure and debanding of the pulmonary artery presented with arterial desaturation in the early postoperative period. Angiography confirmed the echocardiographic findings of hemodynamically significant main pulmonary artery-left atrial fistula. This communication was successfully closed surgically.

Immediate-early MEK-1-dependent stabilization of rat smooth muscle cell cyclooxygenase-2 mRNA by Galpha(q)-coupled receptor signaling.

Activation of Galpha(q)-coupled P2Y nucleotide receptors strongly (>100-fold) induces the rat vascular smooth muscle cell cyclooxygenase-2 (COX-2) mRNA, yet transcription is induced only approximately 3-fold over 1 h. Intact cell decay analysis of tetracycline-suppressible luciferase chimera mRNAs shows that regulated stabilization of the intrinsically unstable mRNA contributes to this response. Deletion mapping of the 2468-base COX-2 mRNA 3'-untranslated region (UTR) shows that a distal, 130-base AU-rich region functions as a cis-acting regulated stabilization response element, which under basal conditions serves as the dominant instability determinant for the 3'-UTR. Regulation of this response is through the p42/44 MAP kinases, whereas the p38 MAP kinases are not involved. The stabilization response element binds avidly and specifically to a prominent nuclear-enriched approximately 90-kDa factor and several less abundantly labeled mRNA binding proteins that are unaffected by P2Y receptor signaling. Although other instability determinants are located throughout the rat COX-2 mRNA 3'-UTR, mitogen signaling only interferes with rapid decay mediated by its most distal 130 bases. A complex of nuclear factors that bind this mRNA region specifically may include candidate targets for regulatory modulation. These observations support the general notion that the rapid induction of immediate-early gene expression through mitogenic receptors involves simultaneous activation of transcriptional and post-transcriptional mechanisms.

Differential regulation of vascular smooth muscle nuclear factor kappa-B by G alpha q-coupled and cytokine receptors.

NF kappaB has been implicated as a downstream effector of G alphaq-coupled receptor signaling, but whether these and cytokine receptors activate NF kappaB similarly remains unclear. Stimulation of rat vascular smooth muscle cell G alphaq-coupled P2Y nucleotide receptors with UTP induces luciferase transcription from a sensitive and specific NF kappaB dependent promoter. However, these responses are only;15% of that to the reference cytokine IL-1 beta. IL-1 beta is a powerful stimulator of I kappaB alpha degradation, RelA nuclear import, and isoform specific NF kappaB enhancer binding in vitro, responses that are not detectable after P2Y receptor stimulation. Expression of two trans -dominant NF kappaB polypeptides suppresses induction of the NF kappaB reporter and also IL-1 beta stimulated monocyte chemoattractant-1 mRNA, which is not induced by UTP. In contrast, UTP induces higher expression of the endogenous COX-2 and IL-6 mRNAs than does IL-1 beta, implying that G alphaq-coupled receptor evokes additional NF kappaB-independent transcription factors in regulating these two genes. P2Y receptors are as effective as the reference growth factor PDGF-BB at inducing CREB, AP-1, SRE and NFAT transcription, which are largely unaffected by IL-1 beta treatment. NF kappaB is less efficiently activated then several other transcriptional effectors of G alphaq-coupled receptor signaling in vascular smooth muscle cells, and is instead preferentially activated by inflammatory cytokines.

Embolization of Gianturco coil into the pulmonary artery requiring emergency surgical intervention.

We report the case of a 20-month-old girl who underwent Gianturco coil embolization to a patent ductus arteriosus in May 1997. The coil migrated to the pulmonary artery. After unsuccessful attempts to retrieve it with snares and forceps, we engaged the coil with an end-hole balloon catheter and pulled it down to the right ventricle. There it became entangled in the tricuspid valvular apparatus and could not be moved farther. Due to concerns about sequelae, the patient was referred for surgery. Following a mid-sternotomy under cardiopulmonary bypass, we removed the coil and ligated the patent ductus arteriosus. The patient made an uneventful recovery. A brief review of the literature is presented.

Coil occlusion of arteriovenous fistula of the vertebral artery in a child.

A 5-year-old boy with congenital fistula between the right vertebral artery and concomitant veins underwent a successful transcatheter fistula occlusion with a Gianturco coil.

Incidence of congenital heart disease in Qatari children.

We surveyed the incidence of congenital heart disease in 49887 native live born children in the period between 1984 to 1994 in Qatar. Each child with clinically suspected congenital heart disease underwent echocardiographic examination. Magnetic resonance imaging, cardiac catheterization and surgical intervention were done at the discretion of the patient's pediatric cardiologist. Virtually no postmortem examinations were performed. Children with congenital heart disease were entered into a computerized database and were then followed for 1-11 years. Congenital heart disease was diagnosed in 610 of 49,887 children for an incidence of 12.23/1000 live births. The reasons for the high incidence were high proportion of small muscular ventricular septal defects discovered before the time of their spontaneous closure, referral to and follow up by a single group of pediatric cardiologists, location of the pediatric cardiology service in the same setting where nearly all of the deliveries took place, freely available health care service, and echocardiographic examination of every child with a clinical diagnosis of congenital heart disease.

The influence of chaotropic reagents on neuronal nitric oxide synthase and its flavoprotein module. Urea and guanidine hydrochloride stimulate NADPH-cytochrome c reductase activity of both proteins.

Changes in flavin and protein fluorescence of neuronal nitric oxide synthase (nNOS) and its flavoprotein module were studied in the presence of urea and compared with those previously reported for cytochrome P450 reductase (CPR) [R. Narayanasami, P. M. Horowitz, and B. S. S. Masters (1995) Arch. Biochem. Biophys. 316, 267-274]. As in the case of CPR, FMN was relatively loosely bound to nNOS and the flavoprotein module, but FAD remained bound at concentrations of up to 2 M urea Protein fluorescence increased progressively with increasing urea concentration, but could not be correlated with changes in flavin binding. NADPH-cytochrome c reductase activity of both nNOS and the flavoprotein module, but not that of CPR, was stimulated at early time points by both urea and guanidine hydrochloride (GnHCl), with levels of initial activity returning to baseline values within 60 min after addition of the chaotropic agent. Thus, at 3-4 M urea, enhancements of reductase activities of 20- and 5-fold with nNOS and the flavoprotein module, respectively, were obtained. Comparable enhancements of 12- and 6- to 7-fold, respectively, were obtained with calmodulin (CaM)/ CaCl2 and 0.5 M GnHCl. Thus, the effects of urea and GnHCl mimicked the stimulating effects of CaM. Separate preincubations of nNOS and cytochrome c with urea or GnHCl prior to initiation of the reductase assay showed that sensitivity to chaotropic agent under these conditions was a property of nNOS and not of cytochrome c. Moreover, when the nonprotein electron acceptor 2,6-dichlorophenolindophenol was employed in place of cytochrome c, comparable stimulation of reductase activity was observed in the presence of either urea or GnHCl. Fluorescence of 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfate in the presence of either nNOS or the flavoprotein module was increased optimally between 3 and 4 M urea, consistent with simultaneous exposure of hydrophobic regions of both proteins to solvent and optimization of reductase activity. FMN release from nNOS, but not from the flavoprotein module, was enhanced by CaM. Addition of FMN or FMN + FAD to nNOS, in the presence or absence of urea, brought about a doubling of initial cytochrome c reductase activity, but did not prevent the eventual decline in activity to basal levels. These data are consistent with conformational changes which favor increased electron transfer similar to that achieved with nNOS in the presence of CaM.

Ventricular conduction defect in isolated noncompaction of the ventricular myocardium.

A 9-month-old boy and 4-month-old girl presented with severe heart failure. The electrocardiogram showed complete and "incomplete" left bundle branch block, respectively. In both infants noncompaction of the ventricular myocardium was diagnosed with two-dimensional echocardiography. These cases are thought to be the first descriptions of the occurrence of left bundle branch block with noncompaction of the ventricular myocardium. Noncompaction of the ventricular myocardium should be added to the list of the causes for left bundle branch block in children.

Underestimation of the severity of pulmonary outflow tract obstruction in the first day of life--Doppler echocardiographic study.

To find out whether there is an underestimated severity of narrowing in obstructive lesions of the pulmonary outflow tract in the first day of life, Doppler measurement of the pulmonary outflow tract gradient and estimation of the pulmonary artery systolic pressure in 15 neonates with pulmonary outflow tract obstruction with a variety of associated lesions were studied in the first twenty-four hours of life (mean thirteen hours, range six to twenty-four) and repeated at the age of twenty-six to seventy-two hours (mean forty-nine). The maximal instantaneous gradient across the pulmonary outflow tract obstruction (22.4 +/- 9.0 mmHg) in the first day of life was significantly lower than at the repeated study (61.0 +/- 19.4 mmHg, (P < 0.001). In 12 patients with patent ductus arteriosus, transductal gradient increased significantly at the repeated examination (19.6 +/- 9.3 vs 48.2 +/- 6.1 mmHg, P < 0.001). The pulmonary outflow tract gradient in these 12 patients was 22.3 +/- 8.4 vs 62.9 +/- 21.1 mmHg, (P < 0.001). The severity of the pulmonary outflow tract obstruction was underestimated in the first twenty-four hours of life. Low gradient across pulmonary outflow tract and low transductal gradient in the first day of life mirrored high pulmonary arterial systolic pressure. At the repeated study the increase in transductal gradient and the increase in the pulmonary outflow tract gradient more accurately represented the severity of pulmonary outflow tract obstruction owing to the decline in the systolic pulmonary arterial pressure.

Doppler imaging of an inadvertent anastomosis of modified Blalock-Taussig shunt to the right upper pulmonary vein.

In a newborn infant with a complex congenital heart disease, a right modified Blalock-Taussig anastomosis was created because of the pulmonary atresia. A 4-mm Gore-Tex tube was inadvertently connected to the upper right pulmonary vein. Clinical signs of an arteriovenous fistula with no improvement in oxygen saturation were noticed immediately after surgery. This complication was confirmed by colour Doppler examination and angiography. Reanastomosis of the tube to the right pulmonary artery was then performed.

Double outlet right ventricle associated with cor triatriatum sinistrum.

Echocardiographic examination of a newborn infant showed a double outlet right ventricle with subpulmonary ventricular septal defect. The left atrium was divided by a membrane-like structure into a proximal chamber receiving pulmonary veins and a distal compartment containing left atrial appendage. To our knowledge, this is the first report of cor triatriatum sinistrum associated with double outlet right ventricle.

Aberrant systemic artery-pulmonary venous fistula: diagnosis with Doppler imaging.

A 6-year-old asymptomatic girl presented with a continuous murmur at two different locations. Using Doppler imaging modalities, a small patent arterial duct and an aberrant systemic artery arising near the coeliac axis, piercing the right hemidiaphragm, and connecting to the right lower pulmonary vein were identified. Angiography confirmed the diagnosis and revealed additional pulmonary abnormalities. Doppler examination helped in planning appropriate angiographic projections and sites of the contrast medium injection.

Occurrence of valvar heart disease in acute rheumatic fever without evident carditis: colour-flow Doppler identification.

OBJECTIVE: To determine the frequency of occurrence of mitral and aortic valvar regurgitation in rheumatic children in whom there was no evidence of carditis acutely or at an earlier attack. DESIGN: Colour flow Doppler imaging was used in a non-randomised study of sequentially admitted children who met the criteria for acute rheumatic fever without clinically evident carditis and patients in whom the disease was quiescent after a previous attack of rheumatic fever. Two separate control groups were used for comparison of the echocardiographic findings, and a group of patients with confirmed rheumatic carditis was included for comparison of acute phase and antistreptococcal reactants. SETTING: A general hospital with the only paediatric inpatient department in Qatar. PATIENTS: From November 1988 to October 1990, 11 children were studied during the acute rheumatic period. In seven additional children the disease was quiescent when they were studied 18 to 36 months after a documented episode of acute rheumatic fever in which there was no evidence of carditis. The control patients were all studied during the same period. MAIN OUTCOME MEASURE: Detection of mitral and aortic regurgitation in patients without clinical evidence of rheumatic carditis in the acute or quiescent stages of the disease. RESULTS: Mitral or mitral and aortic regurgitation was found in 10 of the 11 children studied in the acute rheumatic period. None had a murmur or other evidence of carditis. In all the cases studied the valvar insufficiency was mild. Four of the children studied late in the quiescent period had either aortic or mitral insufficiency by colour flow Doppler evaluation; two children who had previously had valvar insufficiency no longer showed this, and one child without positive findings in the acute phase remained without insufficiency. None of the non-rheumatic control subjects showed mitral or aortic regurgitation. CONCLUSIONS: Colour flow Doppler imaging is a useful method of identifying subclinical mitral and aortic valvar disease at all stages of rheumatic fever when carditis cannot be otherwise detected and is a valuable addition to current diagnostic criteria.

Arteriovenous malformation of the vein of Galen in a newborn diagnosed with color Doppler examination--a case report.

A fourteen-day-old newborn infant presented with severe heart failure due to arteriovenous malformation of the vein of Galen. It was diagnosed by two-dimensional, pulsed-wave and color Doppler echocardiographic imaging. The latter method showed the afferent vessel to be the anterior cerebral artery entering an aneurysm of the vein of Galen at its posterior aspect. Information for surgical anatomic definition appears to be adequately provided by color Doppler examination, which permits avoidance of preoperative angiography.