Development of a Methodological Approach for Data Quality Ontology in Diabetes Management

The role of ontologies in chronic disease management and associated challenges such as defining data quality (DQ) and its specification is a current topic of interest. In domains such as Diabetes Management, a robust Data Quality Ontology (DQO) is required to support the automation of data extraction semantically from Electronic Health Record (EHR) and access and manage DQ, so that the data set is fit for purpose. A five steps strategy is proposed in this paper to create the DQO which captures the semantics of clinical data. It consists of: (1) Knowledge acquisition; (2) Conceptualization; (3) Semantic modeling; (4) Knowledge representation; and (5) Validation. The DQO was applied to the identification of patients with Type 2 Diabetes Mellitus (T2DM) in EHRs, which included an assessment of the DQ of the EHR. The five steps methodology is generalizable and reusable in other domains.

Non-archetypal Type II-like and atypical strains of Toxoplasma gondii infecting marsupials of Australia

Australia is geographically isolated and possesses a remarkable diversity of wildlife species. Marsupials are highly susceptible to infection with the cosmopolitan parasite Toxoplasma gondii. Of 46 marsupials screened for T. gondii by multilocus PCR-DNA sequencing at polymorphic genes (B1, SAG3, GRA6, GRA7), 12 were PCR-positive; the majority (67%; 9/12) were infected by non-archetypal Type II-like or atypical strains. Six novel alleles were detected at B1, indicating greater diversity of genotypes than previously envisaged. Two isolates lethal to marsupials, were avirulent to mice. The data support the conclusion that Australia's isolation may have favoured the persistence of non-archetypal ancestral genotypes.

TRIF, and TRIF-interacting TLRs differentially modulate several adenovirus vector-induced immune responses

The use of Adenovirus (Ad)-based vectors has proven to be a useful platform for the development of gene therapy and vaccine protocols. The immunological mechanisms underlying these properties need to be identified and understood to foster safer, more efficacious use of this important gene transfer platform. Our recent studies have confirmed an important role for MyD88 dependent toll-like receptor (TLR) pathways as mediators of these responses. In this study, we confirm that TLR3, TLR4 and TRIF (TIR-domain-containing adapter-inducing interferon-beta) can also have augmentative or inhibitory roles during Ad-induced immune responses. Importantly, our studies revealed that TLR4 acts to suppress several aspects of the Ad-induced innate immune response, a finding not previously reported for this TLR in any model system. In addition, using MyD88 and TRIF double knockout mice, we demonstrate that the MyD88 and TRIF adaptor proteins can play either additive or redundant roles in mediating certain aspects of Ad vector-induced innate and adaptive immune responses. Furthering this complexity, our model system strongly suggests that non-TLR based systems must not only exist, but also have a significant role to play during Ad vector-mediated induction of adaptive immune responses.

Seroprevalence of Toxoplasma gondii in wild kangaroos using an ELISA

Infection with Toxoplasma gondii is a significant problem in Australian marsupials, and can lead to devastating disease and predispose animals to predation. T. gondii infection in kangaroos is also of public health significance due to the kangaroo meat trade. A moderate seroprevalence of T. gondii was observed in a study of western grey kangaroos located in the Perth metropolitan area in Western Australia. Of 219 kangaroos tested, 15.5% (95%CI: 10.7-20.3) were positive for T. gondii antibodies using an ELISA developed to detect T. gondii IgG in macropod marsupials. When compared with the commercially available MAT (modified agglutination test), the ELISA developed was in absolute agreement and yielded a kappa coefficient of 1.00. Of 18 kangaroos tested for the presence of T. gondii DNA by PCR, the 9 ELISA positive kangaroos tested PCR positive and the 9 ELISA negative kangaroos tested PCR negative indicating the ELISA protocol was both highly specific and sensitive and correlated 100% with the more labour intensive PCR assay.

Awareness modelling in collaborative mobile e-health

E-health based on mobile wireless networks is called mobile e-health. Mobile e-health can facilitate computer-supported cooperative work, which encompasses tasks from email and instant messaging to wireless information sharing through broadband and telecommunication networks. In the development of cooperative management systems, the concept of ‘awareness level’ has been introduced. This is based on factors such as the location and actions of the user involved. Mobile e-health can help to achieve cooperation by providing the right awareness levels at the right time. The improved awareness levels allow health professionals to provide patient care with better quality and efficiency. Mobile e-health systems have the potential to take over the mundane tasks of the doctor so that better quality health services can be provided.

Compensation in pre-synaptic dopaminergic function following nigrostriatal damage in primates

Clinical symptoms of Parkinson's disease only become evident after 70-80% reductions in striatal dopamine. To investigate the importance of pre-synaptic dopaminergic mechanisms in this compensation, we determined the effect of nigrostriatal damage on dopaminergic markers and function in primates. MPTP treatment resulted in a graded dopamine loss with moderate to severe declines in ventromedial striatum (approximately 60-95%) and the greatest reductions (approximately 95-99%) in dorsolateral striatum. A somewhat less severe pattern of loss was observed for striatal nicotinic receptor, tyrosine hydroxylase and vesicular monoamine transporter expression. Declines in striatal dopamine uptake and transporter sites were also less severe than the reduction in dopamine levels, with enhanced dopamine turnover in the dorsolateral striatum after lesioning. The greatest degree of adaptation occurred for nicotine-evoked [(3)H]dopamine release from striatal synaptosomes, which was relatively intact in ventromedial striatum after lesioning, despite > 50% declines in dopamine. This maintenance of evoked release was not due to compensatory alterations in nicotinic receptor characteristics. Rather, there appeared to be a generalized preservation of release processes in ventromedial striatum, with K(+)-evoked release also near control levels after lesioning. These combined compensatory mechanisms help explain the finding that Parkinson's disease symptomatology develops only with major losses of striatal dopamine.

Evidence for emergence of an amphibian iridoviral disease because of human-enhanced spread

Our understanding of origins and spread of emerging infectious diseases has increased dramatically because of recent applications of phylogenetic theory. Iridoviruses are emerging pathogens that cause global amphibian epizootics, including tiger salamander (Ambystoma tigrinum) die-offs throughout western North America. To explain phylogeographical relationships and potential causes for emergence of western North American salamander iridovirus strains, we sequenced major capsid protein and DNA methyltransferase genes, as well as two noncoding regions from 18 geographically widespread isolates. Phylogenetic analyses of sequence data from the capsid protein gene showed shallow genetic divergence (< 1%) among salamander iridovirus strains and monophyly relative to available fish, reptile, and other amphibian iridovirus strains from the genus Ranavirus, suggesting a single introduction and radiation. Analysis of capsid protein sequences also provided support for a closer relationship of tiger salamander virus strains to those isolated from sport fish (e.g. rainbow trout) than other amphibian isolates. Despite monophyly based on capsid protein sequences, there was low genetic divergence among all strains (< 1.1%) based on a supergene analysis of the capsid protein and the two noncoding regions. These analyses also showed polyphyly of strains from Arizona and Colorado, suggesting recent spread. Nested clade analyses indicated both range expansion and long-distance colonization in clades containing virus strains isolated from bait salamanders and the Indiana University axolotl (Ambystoma mexicanum) colony. Human enhancement of viral movement is a mechanism consistent with these results. These findings suggest North American salamander ranaviruses cause emerging disease, as evidenced by apparent recent spread over a broad geographical area.

Cellular and molecular actions of adrenomedullin in glomerular mesangial cells

Adrenomedullin (AM), a potent vasodilatory and hypotensive peptide produces several biological outcomes in glomerular mesangial cells. Mesangial cells are important in the pathogenesis of glomerulonephritis, and therefore the actions of AM on mesangial cells have important clinical and therapeutic implications. This minireview describes the various actions of AM on mesangial cell function and the signal transduction mechanisms involved. As in other systems, most actions of AM can be explained by increase in cAMP levels in the cell, although a few exceptions remain. The fact that most data obtained to date has been in culture, the physiological significance of the actions of AM in mesangial cells is discussed.

Regulation of apoptosis by vasoactive peptides

Although originally discovered because of their ability to affect hemodynamics, vasoactive peptides have been found to function in a variety of capacities including neurotransmission, endocrine functions, and the regulation of cell proliferation. A growing body of evidence describes the ability of vasoactive peptides to regulate cell death by apoptosis in either a positive or negative fashion depending on the peptide and the type of target cell. The available evidence to date is strongest for the peptides endothelin, angiotensin II, vasoactive intestinal peptide, atrial natriuretic peptide, and adrenomedullin. Each of these peptides is discussed, with specific regard to apoptosis, in terms of regulatory activity, target cell specificity, and potential role in pulmonary physiology.

Desensitization and resensitization of adrenomedullin-sensitive receptor in rat mesangial cells

Adrenomedullin is a potent adenylate cyclase activator and a vasodilatory peptide, that has anti-proliferative and apoptotic effects in rat mesangial cells. The present study was designed to determine the mechanisms of desensitization and resensitization of adrenomedullin-sensitive receptor in mesangial cells. Adrenomedullin caused a rapid desensitization of cAMP response evident within 5 min that was almost complete by 1 h of treatment. Pretreatment of cells with forskolin, that activates protein kinase-A by direct activation of adenylate cyclase, also caused adrenomedullin receptor desensitization. In addition, H89 [¿N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride¿], a potent protein kinase-A inhibitor inhibited adrenomedullin-induced desensitization of cAMP response. Adrenomedullin also caused desensitization of isoproterenol- and epinephrine-mediated cAMP accumulation. Furthermore, adrenomedullin induced cross-desensitization of endothelin-stimulated inositol phosphate accumulation. The attenuated cAMP response of adrenomedullin was restored to original levels within 2 h of agonist removal. This resensitization response was blocked by treatment with okadaic acid, a protein phosphatase (protein phosphatase-1/protein phosphatase-2A) inhibitor, during the 2 h resensitization period, indicating that protein phosphatase-1/protein phosphatase-2A may be involved in the resensitization of the adrenomedullin-sensitive receptor. We demonstrate for the first time in rat mesangial cells that the adrenomedullin-sensitive receptor undergoes heterologous desensitization and resensitization, and that it likely involves protein kinase-A and protein phosphatase-1/protein phosphatase-2A, respectively.

Involvement of cAMP-dependent protein kinase and pertussis toxin-sensitive G-proteins in CGRP mediated JNK activation in human neuroblastoma cell line

Calcitonin gene-related peptide (CGRP) is a neuropeptide with potent cardiovascular effects, which include positive inotropic and chronotropic actions, systemic vasodilation, and hypotension in animal and human studies. Human neuroblastoma cells (SK-N-MC) have been used as a model system to study the CGRP receptors and downstream signaling pathways. This investigation was undertaken to study the role of CGRP in the activation of mitogen-activated protein kinases. While exposure of these cells to CGRP had no significant effect on ERK-1 or p38 MAP kinases, JNK activity was stimulated by CGRP in a time- and concentration-dependent fashion. CGRP-mediated JNK-activation was inhibited by CGRP receptor antagonist, CGRP8-37, confirming that this is a receptor-mediated event. In addition, pretreatment of the cells with H-89, protein kinase A inhibitor or pertussis toxin greatly attenuated CGRP-mediated JNK activation suggesting the requirement of cAMP-dependent protein kinase activation and involvement of pertussis toxin-sensitive G-protein in CGRP-mediated JNK activation.

Activation of multiple mitogen-activated protein kinases by recombinant calcitonin gene-related peptide receptor

Calcitonin gene-related peptide is a 37-amino-acid neuropeptide and a potent vasodilator. Although calcitonin gene-related peptide has been shown to have a number of effects in a variety of systems, the mechanisms of action and the intracellular signaling pathways, especially the regulation of mitogen-activated protien kinase (MAPK) pathway, is not known. In the present study we investigated the role of calcitonin gene-related peptide in the regulation of MAPKs in human embryonic kidney (HEK) 293 cells stably transfected with a recombinant porcine calcitonin gene-related peptide-1 receptor. Calcitonin gene-related peptide caused a significant dose-dependent increase in cAMP response and the effect was inhibited by calcitonin gene-related peptide(8-37), the calcitonin gene-related peptide-receptor antagonist. Calcitonin gene-related peptide also caused a time- and concentration-dependent increase in extracellular signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (P38 MAPK) activities, with apparently no significant change in cjun-N-terminal kinase (JNK) activity. Forskolin, a direct activator of adenylyl cyclase also stimulated ERK and P38 activities in these cells suggesting the invovement of cAMP in this process. Calcitonin gene-related peptide-stimulated ERK and P38 MAPK activities were inhibited significantly by calcitonin gene-related peptide receptor antagonist, calcitonin gene-related peptide-(8-37) suggesting the involvement of calcitonin gene-related peptide-1 receptor. Preincubation of the cells with the cAMP-dependent protein kinase inhibitor, H89 [¿N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride¿] inhibited calcitonin gene-related peptide-mediated activation of ERK and p38 kinases. On the other hand, preincubation of the cells with wortmannin ¿[1S-(1alpha,6balpha,9abeta,11alpha, 11bbeta)]-11-(acetyloxy)-1,6b,7,8,9a,10,11, 11b-octahydro-1-(methoxymethyl)-9a,11b-dimethyl-3H-furo[4,3, 2-de]indeno[4,5-h]-2-benzopyran-3,6,9-trione¿, a PI3-kinase inhibitor, attenuated only calcitonin gene-related peptide-induced ERK and not P38 MAPK activation. Thus, these data suggest that activation of ERK by calcitonin gene-related peptide involves a H89-sensitive protein kinase A and a wortmannin-sensitive PI3-kinase while activation of p38 MAPK by calcitonin gene-related peptide involves only the H89 sensitive pathway and is independent of PI3 kinase. This also suggests that although both ERK and P38 can be activated by protein kinase A, the distal signaling components to protein kinase A in the activation of these two kinases (ERK and P38) are different.

Adrenomedullin decreases extracellular signal-regulated kinase activity through an increase in protein phosphatase-2A activity in mesangial cells

Adrenomedullin is a recently identified peptide hormone that has receptors in a number of different systems including renal mesangial cells. We reported recently that adrenomedullin can cause a decrease in extracellular signal-regulated kinase (ERK) activity and increase jun amino-terminal kinase (JNK) and P38 mitogen-activated protein kinase (P38 MAPK) acitivities in rat mesangial cells. Associated with these responses we also reported that adrenomedullin can decrease proliferation and increase apoptosis in mesangial cells. The major aim of the present study was to examine the mechanism of decrease in ERK activity by adrenomedullin and to identify the role of protein phosphatase 2A (PP2A) in the decrease in ERK activity, using okadaic acid [9,10-Deepithio-9,10-didehydroacanthifolicin], a selective inhibitor of PP2A at low nanomolar concentrations. The adrenomedullin-induced decrease in [3H]-thymidine incorporation and increase in apoptosis were reversed by okadaic acid at the concentration that selectively inhibits PP2A. Okadaic acid completely reversed the ERK inhibition caused by adrenomedullin, suggesting that PP2A may be involved in the adrenomedullin-mediated changes in proliferation, apoptosis and ERK activity. PP2A activity in mesangial cells was increased over time following exposure to adrenomedullin. The tyrosine phosphorylation of ERK did not change significantly following adrenomedullin treatment although the ERK activity was decreased significantly. This suggests that the decrease in ERK activity is not mediated through a decrease in MEK (a dual phosphorylating kinase upstream of ERK) or by an increase in MKP-1/2 (a dual specificity phosphatase) activities. Thus we conclude that the mechanism of adrenomedullin-induced decrease in ERK activity in rat mesangial cells is at least in part mediated by an increase in PP2A activity.

Regulation of glomerular mesangial cell proliferation in culture by adrenomedullin

Adrenomedullin is a recently discovered vasodilatory peptide that has been shown to be a potent activator of adenylate cyclase in a variety of cell systems, including rat mesangial cells. The major aim of the present study was to determine the regulation of rat mesangial cell proliferation (using [3H]thymidine incorporation as an index), apoptosis (using nucleosome-associated cytoplasmic DNA fragmentation as an index) and mitogen-activated protein kinase (MAPK) cascade, specifically extracellular signal-regulated kinase (ERK), jun-amino terminal kinase (JNK) and P38 mitogen-activated protein kinase (P38 MAPK) activities, by adrenomedullin-stimulated cyclic AMP-protein kinase-A pathway. Adrenomedullin increased cAMP levels significantly above basal and the response was inhibited by the adrenomedullin receptor antagonist, adrenomedullin-(22-52). Adrenomedullin also decreased [3H]thymidine incorporation and increased nucleosome-associated cytoplasmic DNA fragmentation, in a concentration-dependent fashion. Both these responses were receptor mediated as, adrenomedullin-(22-52) inhibited these effects. The decrease in proliferation and increase in apoptosis were both mimicked by forskolin, a direct adenylate cyclase activator. Adrenomedullin-mediated decrease in proliferation and increase in apoptosis were inhibited by H89 [[N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride]], a potent protein kinase-A inhibitor. Associated with the changes in proliferation and apoptosis, adrenomedullin decreased ERK2 activity, and increased JNK1 and P38 MAPK activities. All these kinase activities, except the increase in JNK1 activity could be simulated using forskolin. In addition, only adrenomedullin-mediated changes in ERK2 and P38 MAPK activities were inhibited by H89 while, adrenomedullin-stimulated JNK1 was not consistently inhibited by the protein kinase-A inhibitor. These results suggest that adrenomedullin might play an important role in mesangial cell turnover and that although adrenomedullin-mediated responses are primarily cAMP-dependent, it does not preclude the involvement of cAMP-independent pathways.

SB203580 reverses adrenomedullin's effect on proliferation and apoptosis in cultured mesangial cells

Adrenomedullin is a potent vasodilatory peptide that has a variety of effects in a number of different systems including kidney. In cultured rat glomerular mesangial cells adrenomedullin increases cAMP, decreases proliferation and increases apoptosis. Associated with the anti-proliferative and apoptotic effects, adrenomedullin also causes a decrease in extracellular signal-regulated kinase2 (ERK2) and an increase in cJun N-terminal kinase 1 (JNK1) and P38 mitogen-activated protein kinase (P38 MAPK) activities. The purpose of the present study was to examine the role of P38 MAPK on adrenomedullin-mediated inhibition of [3H]thymidine incorporation (an index of proliferation) and on adrenomedullin-stimulated nucleosome-associated cytoplasmic DNA fragmentation (an index of apoptosis) in mesangial cells, using a selective inhibitor of P38 MAPK, SB203580 [[4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-im idazole], and also to characterize the proximal signal transduction pathways of the three MAPKs in relation to [3H]thymidine incorporation and cytoplasmic DNA fragmentation using a phosphotidyl inositol-3-kinase inhibitor, wortmannin [[1S-(1alpha,6b alpha,9alphabeta,11alpha,11b beta)]-11-(acetyloxy)-1,6b,7,8,9a,10,11,11b-octahydro-1-(methoxyme thyl)-9a,11b-dimethyl-3H-furo[4,3,2-de]indeno[4,5-h]-2-benzopyran-3,6,9- trione]. SB203580 significantly reversed the effects of adrenomedullin on [3H]thymidine incorporation and cytoplasmic DNA fragmentation, and inhibited only P38 MAPK activity. It had no effect on ERK2 and JNK1 activities. Wortmannin, on the other hand, inhibited only adrenomedullin-stimulated cytoplasmic DNA fragmentation and did not affect adrenomedullin-mediated inhibition of [3H]thymidine incorporation. Wortmannin also inhibited adrenomedullin-stimulated P38 MAPK activity without affecting ERK2 and JNK1 activities. These results indicate that: (a) In rat mesangial cells adrenomedullin-mediated inhibition of [3H]thymidine incorporation and stimulation of nucleosome-associated cytoplasmic DNA fragmentation are sensitive to SB203580, and (b) adrenomedullin activates a P38 MAPK through a wortmannin-sensitive kinase. The data using SB203580 suggest an important physiological role for P38 MAPK in rat mesangial cell proliferation and apoptosis.

Mechanism of adrenomedullin-stimulated hyaluronic acid release in rat mesangial cells

Adrenomedullin is a potent vasodilatory peptide that increases cAMP in a number of different systems including rat mesangial cells. Since mesangial cells play a significant role in glomerular matrix production, we evaluated the effects and molecular mechanisms of adrenomedullin action on hyaluronic acid release, an important extracellular matrix component. Adrenomedullin increased hyaluronic acid release in mesangial cells in a concentration-dependent manner. Forskolin, an adenylate cyclase activator, and dibutyryl-cAMP, a cell permeable cAMP analog, also increased hyaluronic acid release significantly. Adrenomedullin-stimulated hyaluronic acid release was inhibited by the adrenomedullin receptor antagonist, adrenomedullin-(22-52). Inhibition of protein kinase A with H89 [[N-[2-(( p-Bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride)]], a potent protein kinase A inhibitor did not affect adrenomedullin-stimulated hyaluronic acid release; however, H89 [[N-[2-(( p-Bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride]] inhibited forskolin- and dibutyryl-cAMP-induced hyaluronic acid production. In addition, SB203580 [[4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-im idazole), a P38 mitogen-activated protein kinase (P38 MAPK) inhibitor attenuated adrenomedullin-, forskolin-, and dibutyryl-cAMP-stimulated hyaluronic acid release. Hyaluronic acid release induced by adrenomedullin, forskolin and dbcAMP was also inhibited by wortmannin [[1S-(1alpha, 6balpha, 9abeta, 11alpha, 11bbeta)]-11-(Acetyloxy)-1, 6b, 7, 8, 9a, 10, 11, 11b-octahydro-1-(methoxymethyl)-9a, 11b-dimethyl-3H-furo[4, 3, 2-de]indeno[4, 5-h]-2-benzopyran-3, 6, 9-trione]. We conclude that adrenomedullin, forskolin and dbcAMP cause an increase in hyaluronic acid release in rat mesangial cells through a pathway that involves activation of wortmannin-sensitive kinase and P38 MAPK. Although cAMP stimulation and protein kinase A activation can induce hyaluronic acid release. adrenomedullin-stimulated hyaluronic acid release appears to be independent of protein kinase A activation. These data provide the first demonstration of the involvement of P38 MAPK- and wortmannin-sensitive kinase pathways in the stimulation of hyaluronic acid production by rat mesangial cells.

Increased splenic capacity in response to transdermal application of nitroglycerine in the dog

This study was conducted to determine if application of transdermal 2% nitroglycerine ointment (TDNG) to dogs anesthetized with alpha chloralose would produce splenic dilatation by relaxation of venous smooth muscle. Sonomicrometer crystals were applied to the spleen in each of 15 dogs, and a pressure-measuring catheter was inserted into a splenic vein. The sonomicrometer crystals permitted measurement of splenic dimension, which is known to correlate with splenic volume. Ten dogs were given 2.5 cm TDNG/10 kg, and 5 dogs (vehicle controls) were given only petrolatum, both applied to the inner surface of the auricular pinna. Splenic dimension in all dogs receiving TDNG increased significantly (P < .05) by 7.0 +/- 4.8%, whereas splenic dimension in dogs receiving petrolatum did not increase. Splenic venous pressures did not change significantly in either group. Spleens began to dilate 482 +/- 652 seconds after application of TDNG and achieved maximal dilatation at 861 +/- 632 seconds. Splenic dilatation occurred in the absence of elevation of splenic venous pressure, indicating that the dilatation probably resulted from relaxation of splenic smooth muscle. TDNG was absorbed transdermally and produced splenic dilatation in health dogs anesthetized with alpha chloralose. If the spleen is a sentinel for peripheral veins, then TDNG may increase venous capacity, retaining blood from the lungs and thereby functioning to reduce pulmonary congestion and edema in dogs with left-sided heart failure.