CAD/CAM options in dental implant treatment planning.

Several software platforms are available that use computerized tomography files and proprietary 3-D reformatting to aid in diagnosis, plan implant location, and complete the surgical placement and restoration of dental implants. This article will review traditional versus computerized model of surgical planning, advantages and disadvantages of computer-aided design/computer-aided manufacturing planning, variability in treatment sequence, and a cost analysis of investment into this treatment modality.

Herpes simplex virus infection induces phosphorylation and delocalization of emerin, a key inner nuclear membrane protein.

The inner nuclear membrane (INM) contains specialized membrane proteins that selectively interact with nuclear components including the lamina, chromatin, and DNA. Alterations in the organization of and interactions with INM and lamina components are likely to play important roles in herpesvirus replication and, in particular, exit from the nucleus. Emerin, a member of the LEM domain class of INM proteins, binds a number of nuclear components including lamins, the DNA-bridging protein BAF, and F-actin and is thought to be involved in maintaining nuclear integrity. Here we report that emerin is quantitatively modified during herpes simplex virus (HSV) infection. Modification begins early in infection, involves multiple steps, and is reversed by phosphatase treatment. Emerin phosphorylation during infection involves one or more cellular kinases but can also be influenced by the US3 viral kinase, a protein whose function is known to be involved in HSV nuclear egress. The results from biochemical extraction analyses and from immunofluorescence of the detergent-resistant population demonstrate that emerin association with the INM significantly reduced during infection. We propose that the induction of emerin phosphorylation in infected cells may be involved in nuclear egress and uncoupling interactions with targets such as the lamina, chromatin, or cytoskeletal components.

Alpha1-adrenergic receptor signaling is localized to caveolae in neonatal rat cardiomyocytes.

In neonatal rat cardiomyocytes, phosphatidylinositol(4,5)bisphosphate (PIP2) is a precursor of second messengers, a stabilizer of ion channels and exchangers, an anchor point for the cytoskeleton and, in addition, can serve as a signaling molecule in its own right. We examined the possibility that sarcolemmal PIP2 exists in different pools and that only one of these provides the substrate for alpha1-adrenergic receptor activated phospholipase C (PLC). Membranes were separated on the basis of buoyant density, and the light lipid raft fractions were further separated into caveolae and non-caveolar rafts using immunoprecipitation. PIP2 was principally located in the light lipid raft fractions and was equally distributed between caveolae and non-caveolar membranes. Heavier membrane fractions also contained some PIP2. Addition of the alpha1-adrenergic receptor agonist phenylephrine (50 microM) caused reductions in PIP2, but only in caveolae. PIP2 in other fractions was unaffected. In agreement with this, PLCbeta1 and, to a lesser extent, Galphaq were concentrated in this fraction. PLCbeta3 was primarily observed in heavier membranes. We conclude that PIP2 in cardiomyocyte sarcolemma is compartmentalized and that alpha1-adrenergic receptor signaling is localized to caveolae.

Regulation of the proapoptotic factor FOXO1 (FKHR) in cardiomyocytes by growth factors and alpha1-adrenergic agonists.

Apoptotic responses in cardiomyocytes are opposed by the protein kinase Akt (protein kinase B) and thus can be suppressed by a number of growth factors and cytokines. In some cell types, Akt phosphorylates and inactivates members of the forkhead box (FOXO) family of transcription factors that are active in regulating the expression of proapoptotic cytokines and signaling intermediates. In the current study, we investigated the possibility that FOXO1 (FKHR) was expressed, regulated, and functional in cardiomyocytes. Addition of epidermal growth factor (EGF) (10 nM) to neonatal rat cardiomyocytes caused rapid phosphorylation of Akt and slower FOXO1 phosphorylation. In contrast, the alpha1-adrenergic receptor agonist phenylephrine (50 microM) did not phosphorylate Akt and caused dephosphorylation of FOXO1 acutely and increased FOXO1 expression with chronic exposure. Phenylephrine, but not EGF, caused nuclear translocation of FOXO1, a response that is associated with dephosphorylation. Overexpression of FOXO1 activated transcription of the proapoptotic cytokine, TNFalpha-related apoptosis-inducing ligand, as indicated by reporter gene activity. This response was enhanced by phenylephrine and inhibited by EGF. FOXO1 is expressed, regulated, and functionally active in cardiomyocytes and thus may contribute to apoptotic responses in heart.

UTP transactivates epidermal growth factor receptors and promotes cardiomyocyte hypertrophy despite inhibiting transcription of the hypertrophic marker gene, atrial natriuretic peptide.

In neonatal rat ventricular myocytes, activation of receptors that couple to the G(q) family of heterotrimeric G proteins causes hypertrophic growth, together with expression of "hypertrophic marker" genes, such as atrial natriuretic peptide (ANP) and myosin light chain 2 (MLC2). As reported previously for other G(q)-coupled receptors, stimulation of alpha(1)-adrenergic receptors with phenylephrine (50 microM) caused phosphorylation of epidermal growth factor (EGF) receptors as well as activation of ERK1/2, cellular growth, and ANP transcription. These responses depended on EGF receptor activation. In marked contrast, stimulation of G(q)-coupled purinergic receptors with UTP caused EGF receptor phosphorylation, ERK1/2 activation, and cellular growth but minimal increases in ANP transcription. UTP inhibited phenylephrine-dependent transcription from ANP and MLC2 promoters but not transcription from myoglobin promoters or from AP-1 elements. Myocardin is a muscle-specific transcription enhancer that activates transcription from ANP and MLC2 promoters but not myoglobin promoters or AP-1 elements. UTP inhibited ANP and MLC2 responses to overexpressed myocardin but did not inhibit responses to c-Jun, GATA4, or serum response factor, all of which are active in nonmuscle cells. Thus, UTP inhibits transcriptional responses to phenylephrine only at cardiac-specific promoters, and this may involve the muscle-specific transcription enhancer, myocardin. These studies show that EGF receptor activation is necessary but not sufficient for ANP and MLC2 responses to activation of G(q)-coupled receptors in ventricular myocytes, because inhibitory mechanisms can oppose such stimulation. ANP is a compensatory and protective factor in cardiac hypertrophy, and mechanisms that reduce its generation need to be defined.

UTP but not ATP causes hypertrophic growth in neonatal rat cardiomyocytes.

Addition of ATP to neonatal rat cardiomyocytes has been reported to inhibit hypertrophic growth responses, even though G(q)-coupled receptors are activated. In the current study, we investigated hypertrophic responses to activation of G(q)-coupled-purinergic receptors on cardiomyocytes using UTP as an alternative agonist to ATP. UTP (100 microM) activated phospholipase C via G(q) similarly to ATP, and responses to the two agonists were not additive. Similarly, UTP and ATP both induced phosphorylation of extracellular signal-regulated kinase (ERK1/2), while having little effect on p38 mitogen-activated protein kinase or c-Jun NH(2)-terminal kinase. However, addition of UTP (100 microM) to cardiomyocytes caused hypertrophic growth indicated by increased protein content without DNA synthesis. ATP (100 microM) caused no increase in protein. We conclude that activation of purinergic receptors on neonatal cardiomyocytes initiates hypertrophic signaling pathways, but that prolonged exposure to ATP, but not UTP, has growth-inhibitory effects.

Psychological differences between children with and without chronic encopresis.

OBJECTIVE: To validate a theoretical model of encopresis in terms of psychological factors that differentiates children with and without chronic encopresis and to identify scales that demonstrate these differences. METHODS: Eighty-six children with encopresis were compared to 62 nonsymptomatic children on five psychometric instruments. Differences in the mean scores and the percentages of children falling beyond preselected clinical thresholds were compared across the patient-control groups. RESULTS: Children with encopresis were found to have more anxiety/depression symptoms, family environments with less expressiveness and poorer organization, more attention difficulties, greater social problems, more disruptive behavior, and poorer school performance (ps =.01 < or =.001 on 15/20 subscales). There were no differences in self-esteem. On those subscales where proportionately more encopretic children exceeded clinical thresholds, approximately 20% more of the encopretic children exceeded thresholds than control children. CONCLUSIONS: As a group, children with encopresis differ from children without encopresis on a variety of psychological parameters. However, only a minority of children with encopresis demonstrated clinically significant elevations in these parameters. Identification and treatment of such clinical issues may enhance treatment efficacy.