The NS1 protein of tick-borne encephalitis virus forms multimeric species upon secretion from the host cell

Flaviviruses elicit a humoral immune response to two virus-encoded, membrane-associated glycoproteins. One is the major virion surface envelope protein (E), which is recognized by antibody, whereas the other is a secreted, heavily glycosylated non-structural protein (NS1). Inoculation with either protein can give rise to a protective immune response, as can the passive transfer of E and NS1 monospecific monoclonal antibodies. Experiments reported here demonstrate that the secreted form of NS1, whether from cells infected with tick-borne encephalitis virus (TBEV) or from cells infected with a defective recombinant adenovirus containing the NS1 gene, occurs chiefly as a pentamer or hexamer and occasionally as a decamer or dodecamer. Intracellular forms of this protein however occur only as dimers. The higher M(r) forms secreted from the cell are exquisitely sensitive to detergent, suggesting they are held together by hydrophobic bonds. Both intracellular and extracellular forms of the dimer can be dissociated by heat, but at different temperatures. Unlike similar proteins from mosquito-borne viruses. NS1 from TBEV-infected cells cannot be dissociated at ambient temperatures by extremes of pH. Studies on the antigenic structure of this protein show it to have several highly conserved epitopes, confirming similar earlier conclusions from amino acid sequence analyses.

The glutaraldehyde-stabilized porcine aortic valve xenograft. II. Effect of fixation with or without pressure on the tensile viscoelastic properties of the leaflet material

We have examined the tensile viscoelastic properties of circumferential and radial strips of porcine aortic valve leaflets following fixation in glutaraldehyde and formaldehyde, with or without pressure. After aldehyde treatment, the radial strips remained weaker and less stiff than circumferential strips and responded slightly differently to the treatment. After fixation, with or without pressure, the radial strips showed large changes in stress-strain and hysteresis responses due to initial loading, and there was a twofold reduction in tensile strength and final stiffness. For strips in both directions, fixation without pressure produced doubled extensibility and a ramping stress-strain curve. Permanent (plastic) deformation of 5-20% occurred as a result of cyclic loading, stress relaxation, and creep experiments. Pressure fixation, however, produced little change in stress-strain results other than a simple shift to lower strain and produced no plasticity. Both methods of fixation reduced stress relaxation and creep. Mechanical test results are consistent with a loss of ground substance matrix during fixation. Reductions in tensile strength after fixation may be due to "riveting" of collagen geometry, producing local stress concentrations.

Mechanical loading of bovine pericardium accelerates enzymatic degradation

Bioprosthetic heart valves fail as the result of two simultaneous processes: structural deterioration and calcification. Leaflet deterioration and perforation have been correlated with regions of highest stress in the tissue. The failures have long been assumed to be due to simple mechanical fatigue of the collagen fibre architecture; however, we have hypothesized that local stresses-and particularly dynamic stresses-accelerate local proteolysis, leading to tissue failure. This study addresses that hypothesis. Using a novel, custom-built microtensile culture system, strips of bovine pericardium were subjected to static and dynamic loads while being exposed to solutions of microbial collagenase or trypsin (a non-specific proteolytic enzyme). The time to extend to 30% strain (defined here as time to failure) was recorded. After failure, the percentage of collagen solubilized was calculated based on the amount of hydroxyproline present in solution. All data were analyzed by analysis of variance (ANOVA). In collagenase, exposure to static load significantly decreased the time to failure (P < 0.002) due to increased mean rate of collagen solubilization. Importantly, specimens exposed to collagenase and dynamic load failed faster than those exposed to collagenase under the same average static load (P = 0.02). In trypsin, by contrast, static load never led to failure and produced only minimal degradation. Under dynamic load, however, specimens exposed to collagenase, trypsin, and even Tris/CaCl2 buffer solution, all failed. Only samples exposed to Hanks' physiological solution did not fail. Failure of the specimens exposed to trypsin and Tris/CaCl2 suggests that the non-collagenous components and the calcium-dependent proteolytic enzymes present in pericardial tissue may play roles in the pathogenesis of bioprosthetic heart valve degeneration.

Functional Coronary Angiography-Derived Index of Microcirculatory Resistance in Patients With ST-Segment Elevation Myocardial Infarction

OBJECTIVES

The aim of this study was to evaluate the diagnostic accuracy and prognostic implications of angiography-derived index of microcirculatory resistance (angio-IMR) in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

The index of microcirculatory resistance (IMR) is a reliable invasive measure of coronary microvascular dysfunction in patients with STEMI. A functional coronary angiography-derived method to estimate IMR is a wire- and hyperemic agent-free alternative to IMR.

METHODS

The study population consisted of 2 independent cohorts. The diagnostic cohort comprised patients with IMR from the culprit vessel immediately after successful primary percutaneous coronary intervention (n = 31). The prognostic cohort was patients with STEMI who were successfully treated with primary percutaneous coronary intervention and followed for 10 years from the index procedure (n = 309). Angio-IMR was calculated using computational flow and pressure simulation. The primary outcome was a composite of cardiac death and readmission for heart failure over 10 years of follow-up.

RESULTS

In the diagnostic cohort, angio-IMR correlated well with IMR (R = 0.778; P < 0.001). Sensitivity, specificity, accuracy, and area under the curve of angio-IMR to predict IMR >40 U were 75.0%, 84.2%, 80.6%, and 0.899 (95% confidence interval: 0.786-0.949), respectively. In the prognostic cohort, patients with angio-IMR >40 U showed significantly higher risk for cardiac death or readmission for heart failure than did those with angio-IMR ≤40 U (46.7% vs 16.6%; adjusted hazard ratio: 2.909; 95% CI: 1.670-5.067; P < 0.001). Angio-IMR >40 U was an independent predictor of cardiac death or readmission for heart failure (hazard ratio: 2.173; 95% CI: 1.157-4.079; P = 0.016) and showed incremental prognostic value compared with a model with clinical risk factors only (C index = 0.726 vs 0.666 [P < 0.001], net reclassification index = 0.704 [P < 0.001]).

CONCLUSIONS

Angio-IMR showed high correlation and diagnostic accuracy to predict IMR. Patients with STEMI with angio-IMR >40 U showed a significantly higher risk for cardiac death or readmission for heart failure than those with preserved angio-IMR values. (Prognostic Implication of Angiography-Derived IMR in STEMI Patients; NCT04628377).

Biaxial mechanical/structural effects of equibiaxial strain during crosslinking of bovine pericardial xenograft materials

We have investigated the effect of biaxial constraint during glutaraldehyde crosslinking on the equibiaxial mechanical properties of bovine pericardium. Crosslinking of cruciate samples was carried out with: (i) no applied load, (ii) an initial 25 g ( approximately 30 kPa) equibiaxial load, or (iii) an initial 200 g (approximately 250 kPa) equibiaxial load. All loading during crosslinking was done under a defined initial equibiaxial load and subsequently fixed biaxial strain. Load changes during crosslinking were monitored. Mechanical testing and constraint during crosslinking were carried out in a custom-built biaxial servo-hydraulic testing system incorporating four actuators with phase-controlled waveform synthesis, high frame-rate video dimension analysis, and computer-interfaced data acquisition. The paired biaxial stress strain responses under equibiaxial loading at 1 Hz (before and after treatment) were evaluated for changes in anisotropic extensibility by calculation of an anisotropy index. Scanning electron microscopy (SEM) was performed on freeze-fractured samples to relate collagen crimp morphology to constraint during crosslinking. Fresh tissue was markedly anisotropic with the base-to-apex direction of the pericardium being less extensible and stiffer than the circumferential direction. After unconstrained crosslinking, the extensibility in the circumferential direction, the stiffness in the base-to-apex direction, and the tissue's anisotropy were all reduced. Anisotropy was preserved in the tissue treated with an applied 25 g load; however, tissue treated with an applied 200 g load became extremely stiff and nearly isotropic. SEM micrographs correlated well with observed extensibility in that the collagen fibre morphology changed from very crimped (unconstrained crosslinking), to straight (200 g applied load). Biaxial stress-fixation may allow engineering of bioprosthetic materials for specific medical applications.

Inhibition of lipid peroxidation and oxidative DNA damage by Ganoderma lucidum

Reactive oxygen species (ROS), such as superoxide anions and hydroxyl radicals, are associated with carcinogenesis and other pathophysiological conditions. Therefore, elimination or inactivation of ROS or inhibition of their excess generation may be beneficial in terms of reducing the risk for cancer and other diseases. Ganoderma lucidum has been used in traditional oriental medicine and has potential antiinflammatory and antioxidant activities. In the present study, we tested the amino-polysaccharide fraction (designated as 'G009') from Ganoderma lucidum for the ability to protect against oxidative damage induced by ROS. G009 significantly inhibited iron-induced lipid peroxidation in rat brain homogenates and showed a dose-dependent inactivation of hydroxyl radicals and superoxide anions. It also reduced strand breakage in phiX174 supercoiled DNA caused by UV-induced photolysis of hydrogen peroxide and attenuated phorbol ester-induced generation of superoxide anions in differentiated human promyelocytic leukaemia (HL-60) cells. These findings suggest that G009 from Ganoderma lucidum possesses chemopreventive potential.

Integrated Myocardial Perfusion Imaging Diagnostics Improve Detection of Functionally Significant Coronary Artery Stenosis by 13 N-ammonia Positron Emission Tomography

Background—

Recent evidence suggests that the diagnostic accuracy of myocardial perfusion imaging is improved by quantifying stress myocardial blood flow (MBF) in absolute terms. We evaluated a comprehensive quantitative 13 N-ammonia positron emission tomography ( 13 NH 3 -PET) diagnostic panel, including stress MBF, coronary flow reserve (CFR), and relative flow reserve (RFR) in conjunction with relative perfusion defect (PD) assessments to better detect functionally significant coronary artery stenosis.

Methods and Results—

A total of 130 patients (307 vessels) with coronary artery disease underwent both 13 NH 3 -PET and invasive coronary angiography with fractional flow reserve (FFR) measurement. Diagnostic accuracy, optimal cut points, and discrimination indices of respective 13 NH 3 -PET quantitative measures were compared, with FFR as standard reference. The capacity to discern disease with stepwise addition of stress MBF, CFR, and RFR to qualitatively assessed relative PD was also gauged, using the category-free net reclassification index. All quantitative measures showed significant correlation with FFR (PET-derived CFR, r =0.388; stress MBF, r =0.496; and RFR, r =0.780; all P <0.001). Optimal respective cut points for FFR ≤0.8 and ≤0.75 were 1.99 and 1.84 mL/min per g for stress MBF and 2.12 and 2.00 for PET-derived CFR. Discrimination indices of quantitative measures that correlated with FFR ≤0.8 were all significantly higher than that of relative PD (area under the curve: 0.626, 0.730, 0.806, and 0.897 for relative PD, CFR, stress MBF, and RFR, respectively; overall comparison P <0.001). The capacity for functionally significant coronary stenosis was incrementally improved by the successive addition of CFR (net reclassification index=0.629), stress MBF (net reclassification index=0.950), and RFR (net reclassification index=1.253; all P <0.001) to relative PD.

Conclusions—

Integrating quantitative 13 NH 3 -PET measures with qualitative myocardial perfusion assessment provides superior diagnostic accuracy and improves the capacity to detect functionally significant coronary artery stenosis.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifiers: NCT01621438 and NCT01366404.

Rosai-Dorfman disease mimicking parasagittal meningioma: case presentation and review of literature

BACKGROUND

Sinus histiocytosis with massive lymphadenopathy was originally described by Rosai and Dorfman in 1969. It usually presents with bilateral painless cervical lymphadenopathy. In extremely rare circumstances, the CNS can be affected. Only 21 prior cases of intracranial involvement have been reported.

CASE REPORT

A 33-year-old white male presented with a 2-week history of progressive cephalgia. The patient underwent MRI testing that revealed an enhancing mass in the right parasagittal region with associated edema. Preoperative diagnosis was right parasagittal meningioma. The patient underwent craniotomy with complete resection of the mass. Histopathology was compatible with Rosai-Dorfman disease (RDD).

CONCLUSION

Rosai-Dorfman disease is rarely found intracranially; however, its ability to mimic meningioma as well as other pathologies underlines its importance. With so few reported cases of intracranial involvement, more experience will be necessary before this clinical presentation and prognosis can be clearly outlined.

The Epstein-Barr virus latency BamHI-Q promoter is positively regulated by STATs and Zta interference with JAK/STAT activation leads to loss of BamHI-Q promoter activity

In Epstein-Barr virus (EBV)-associated tumors in nonimmunocompromised patients, EBV gene expression is highly restricted. EBV-encoded nuclear antigen (EBNA)-1 is expressed, whereas the immunogenic and proliferative EBNAs are not. This pattern of EBNA expression is generated by usage of the BamHI-Q promoter (Qp). We have determined that the JAK/STAT pathway positively regulates Qp activity. In transient-transfection assays, a Qp-CAT reporter was activated by cotransfected JAK-1 and by treatment of cells with the cytokine IL-6. The ability of Qp to bind signal transducer and activator of transcription (STAT) proteins was directly demonstrated by electrophoretic mobility-shift assay, and mutation of potential STAT-binding sites reduced Qp responsiveness to Janus kinase (JAK)-1. Consistent with a role for STATs in Qp function, Qp using Burkitt's lymphoma Rael cells and cultured nasopharyngeal carcinoma (NPC) cells contained nuclear STAT protein. We investigated whether the inability to maintain EBV-positive NPC cell lines in culture was related to Qp activity. Passaging of the NPC cell line HK666 led to activation of expression of BZLF1, which encodes Zta and loss of Qp function. Transient expression assays linked Zta expression to the down-regulation of Qp. Cotransfection of Zta reduced Qp activity in reporter assays. This negative regulation required Zta DNA-binding activity. We provide evidence that Zta up-regulation of p53 leads to p53-mediated interference with JAK/STAT activation of Qp. The data imply that JAK/STAT signaling has a role in EBV-associated malignancies.

Germline transformation of the sawfly, Athalia rosae (Hymenoptera: Symphyta), mediated by a piggyBac-derived vector

A piggyBac construct carrying two green fluorescent protein (GFP)-coding sequences one driven by Bombyx mori actin gene promoter and the other by Drosophila melanogaster heat-shock protein 70 (hsp70) promoter were injected together with a nonautonomous helper plasmid containing an active piggyBac transposase gene into the posterior end of mature unfertilized eggs dissected from the ovaries of Athalia rosae (Hymenoptera: Symphyta). These injected eggs, which developed as haploid male embryos upon artificial activation, were cultured to adulthood. Of 278 injected eggs, 61 grew to G(0) haploid adult males. These G(0) haploid males were individually mated to diploid females. The progeny embryos (G(1) generation) were examined for GFP expression. Four GFP-positive embryos (from three independent G(0) matings) were obtained. Two eclosed as diploid adult G(1) females. Mature unfertilized eggs dissected from the GFP-positive G(1) diploid females were activated artificially, and the resultant embryos were examined for GFP expression, separated and cultured to adulthood (G(2) generation). The G(2) haploid embryos segregated to GFP-positive and -negative individuals. By mating the G(2) adult haploid males individually to diploid females, stocks were established in which the piggyBac construct was stably integrated into the genome, as evidenced by GFP expression and Southern blot hybridization. The piggyBac transposition occurred at its canonical target TTAA sequence. These results, which demonstrate the first successful stable transposon-mediated germline transformation in Hymenoptera, will expand the usefulness of the piggyBac vector.

Antitumor activity of 7-[2-(N-isopropylamino)ethyl]-(20S)-camptothecin, CKD602, as a potent DNA topoisomerase I inhibitor

We developed a novel water-soluble camptothecin analogue, CKD602, and evaluated the inhibition of topoisomerase I and the antitumor activities against mammalian tumor cells and human tumor xenografts. CKD602 was a nanomolar inhibitor of the topoisomerase I enzyme in the cleavable complex assay. CKD602 was found to be 3 times and slightly more potent than topotecan and camptothecin as inhibitors of topoisomerase, respectively. In tumor cell cytotoxicity, CKD602 was more potent than topotecan in 14 out of 26 human cancer cell lines tested, while it was comparable to camptothecin. CKD602 was tested for the in vivo antitumor activity against the human tumor xenograft models. CKD602 was able to induce regression of established HT-29, WIDR and CX-1 colon tumors, LX-1 lung tumor, MX-1 breast tumor and SKOV-3 ovarian tumor as much as 80, 94, 76, 67, 87% and 88%, respectively, with comparable body weight changes to those of topotecan. Also the therapeutic margin (R/Emax: maximum tolerance dose/ED58) of CKD602 was significantly higher than that of topotecan by 4 times. Efficacy was determined at the maximal tolerated dose levels using schedule dependent i.p. administration in mice bearing L1210 leukemia. On a Q4dx4 (every 4 day for 4 doses) schedule, the maximum tolerated dose (MTD) was 25 mg/kg per administration, which caused great weight loss and lethality in < 5% tumor bearing mouse. This schedule brought significant increase in life span (ILS), 212%, with 33% of long-term survivals. The ex vivo antitumor activity of CKD602 was compared with that of topotecan and the mean antitumor index (ATI) values recorded for CKD602 were significantly higher than that noted for topotecan. From these results, CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I.

Clinical implications of three-vessel fractional flow reserve measurement in patients with coronary artery disease

Aims

There are limited data on the clinical implications of total physiologic atherosclerotic burden assessed by invasive physiologic studies in patients with coronary artery disease. We investigated the prognostic implications of total physiologic atherosclerotic burden assessed by total sum of fractional flow reserve (FFR) in three vessels (3V-FFR).

Methods and results

A total of 1136 patients underwent FFR measurement in three vessels (3V FFR-FRIENDS study, NCT01621438). The patients were classified into high and low 3V-FFR groups according to the median value of 3V-FFR (2.72). The primary endpoint was major adverse cardiac events (MACE, a composite of cardiac death, myocardial infarction and ischaemia-driven revascularization) at 2 years. Mean angiographic percent diameter stenosis and FFR were 43.7 ± 19.3% and 0.90 ± 0.08, respectively. There was a negative correlation between 3V-FFR and estimated 2-year MACE rate (P < 0.001). The patients in low 3V-FFR group showed a higher risk of 2-year MACE than those in the high 3V-FFR group [(7.1% vs. 3.8%, hazard ratio (HR) 2.205, 95% confidence interval (CI) 1.201-4.048, P = 0.011]. The higher 2-year MACE rate was mainly driven by the higher rate of ischaemia-driven revascularization in the low 3V-FFR group (6.2% vs. 2.7%, HR 2.568, 95% CI 1.283-5.140, P = 0.008). In a multivariable adjusted model, low 3V-FFR was an independent predictor of MACE (HR 2.031, 95% CI 1.078-3.830, P = 0.029).

Conclusion

Patients with high total physiologic atherosclerotic burden assessed by 3V-FFR showed higher risk of 2-year clinical events than those with low total physiologic atherosclerotic burden. The difference was mainly driven by ischaemia-driven revascularization for both functionally significant and insignificant lesions at baseline. Three-vessel FFR might be used as a prognostic indicator in patients with coronary artery disease.

Clinical trial registration

3V FFR-FRIENDS study (https://clinicaltrials.gov/ct2/show/NCT01621438, NCT01621438).

Clinical Relevance of 18F-Sodium Fluoride Positron-Emission Tomography in Noninvasive Identification of High-Risk Plaque in Patients With Coronary Artery Disease

BACKGROUND

¹⁸F-sodium fluoride (¹⁸F-NaF) positron-emission tomography has been introduced as a potential noninvasive imaging tool to identify plaques with high-risk characteristics in patients with coronary artery disease. We sought to evaluate the clinical relevance of ¹⁸F-NaF uptake using optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography in patients with coronary artery disease.

METHODS AND RESULTS

The target population consisted of 51 prospectively enrolled patients (93 stenoses) who underwent ¹⁸F-NaF positron-emission tomography before invasive coronary angiography. ¹⁸F-NaF uptake was compared with IVUS- and OCT-derived plaque characteristics. In the coronary computed tomography angiography subgroup (46 lesions), qualitative lesion characteristics were compared between ¹⁸F-NaF-positive and ¹⁸F-NaF-negative plaques using adverse plaque characteristics. The plaques with ¹⁸F-NaF uptake showed significantly higher plaque burden, more frequent posterior attenuation and positive remodeling in IVUS, and significantly higher maximum lipid arc and more frequent microvessels in OCT (all P<0.05). There were no differences in minimum lumen area and area of calcium between ¹⁸F-NaF-positive and ¹⁸F-NaF-negative lesions. Among 51 lesions with ¹⁸F-NaF-positive uptake, 48 lesions (94.1%) had at least one of high-risk characteristics. The ¹⁸F-NaF tissue-to-background ratio in plaques with high-risk characteristics was significantly higher than in those without (1.09 [95% confidence interval, 0.85-1.34] versus 0.62 [95% confidence interval, 0.42-0.82], P<0.001 for IVUS definition; 0.76 [95% confidence interval, 0.54-0.98] versus 0.42 [95% confidence interval, 0.21-0.62], P=0.014 for OCT definition). Among the 15 lesions that met both IVUS- and OCT-defined criteria for high-risk plaque, 14 (93.3%) showed ¹⁸F-NaF-positive uptake. There was no difference in the prevalence of plaques with any adverse plaque characteristics between ¹⁸F-NaF-positive and ¹⁸F-NaF-negative plaques in the coronary computed tomography angiography subgroup (85.2% versus 78.9%; P=0.583).

CONCLUSIONS

This study's results suggest that ¹⁸F-NaF positron-emission tomography can be a useful noninvasive diagnostic tool to identify and localize plaque with high-risk characteristics.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02388412.

The localization and characterization of substance P and substance K in striatonigral neurons

Specific substance P and substance K radioimmunoassays coupled to high-performance liquid chromatography were used to characterize striatal and nigral tachykinin immunoreactivity. Using these assays, authentic substance P and substance K accounted for nearly all substance P and substance K immunoreactivity, respectively. A series of coronal knife cuts of the striatum caused parallel depletions in nigral substance P and substance K, consistent with the possible colocalization of these tachykinins in striatonigral neurons.

Increased beta-carboline 9N-methyltransferase activity in the frontal cortex in Parkinson's disease

Enzymatic beta-carboline N-methyltransferase activities generate N-methylated beta-carbolinium cations that are analogs of the parkinsonian-producing neurotoxin MPP+. We measured beta-carboline-2N-methyltransferase and beta-carboline-9N-methyltransferase activities in the supernatant and particulate fractions from postmortem human brains. These N-methyltransferase activities were assessed in the substantia nigra, putamen, and frontal cortex from control and Parkinson's disease cases. No significant differences were measured in any brain region in particulate and supernatant fraction beta-carboline 2N-methyltransferase activity or particulate fraction beta-carboline 9N-methyltransferase activity. Likewise, supernatant fraction beta-carboline 9N-methyltransferase activity was similar in the putamen and substantia nigra from Parkinson's disease and control cases. Unexpectedly, supernatant fraction beta-carboline 9N-methyltransferase activity was increased fourfold in Parkinson's disease frontal cortex (P < 0.05), suggesting that beta-carboline N-methylation may play a role in Parkinson's disease.

Reduction of calcineurin enzymatic activity in Alzheimer's disease: correlation with neuropathologic changes

Neurofibrillary tangles (NFT), neuritic plaques, and dystrophic neurites are the classic neuropathologic hallmarks of Alzheimer's disease (AD), all of which contain to varying degrees abnormally and/or hyperphosphorylated forms of the microtubule-associated protein tau. Protein phosphatase 2B (calcineurin) dephosphorylates tau isolated from AD brains to control levels in vitro as well as regulates tau phosphorylation and function in vivo. It has been hypothesized that the changes in tau phosphorylation observed in AD may be due to increases in kinase activity and/or decreases in phosphatase activity. In order to investigate the latter possibility, we examined calcineurin enzyme activity using the substrate para-nitrophenyl-phosphate (pNPP) in postmortem brain samples from individuals with moderate to severe AD (n = 8) and age-matched controls (n = 7). The stimulation of calcineurin activity by manganese chloride (1 mM) was reduced by 60% (p < 0.01) in whole-cell homogenates prepared from AD temporal cortex (Brodmann area 38). On the other hand, in P2 membrane fractions, the stimulation of calcineurin activity by manganese chloride as well as nickel chloride (1 mM) was reduced by 37% (p < 0.05) and 79% (p < 0.01), respectively. The manganese-stimulated calcineurin activity in the temporal cortex inversely correlated with both the number of NFT (r = -0.60, p < 0.02) and neuritic/core plaques (r = -0.63, p < 0.02) in whole-cell homogenates, but only with NFT (r = -0.61, p < 0.02) in P2 membrane fractions. The nickel-stimulated calcineurin activity did not correlate with neuropathology measures in either whole-cell or P2 membrane fractions. In striate visual cortex (Brodmann area 17), an area relatively unaffected in AD, neither whole-cell nor P2 membrane calcineurin activity were significantly altered. To our knowledge, this is the first report of a reduction in calcineurin phosphatase activity in AD which correlates with the neuropathological features in a region-, subcellular fraction-, and divalent cation-specific manner.

Metformin ameliorates IL-6-induced hepatic insulin resistance via induction of orphan nuclear receptor small heterodimer partner (SHP) in mouse models

AIMS/HYPOTHESIS

IL-6 is a proinflammatory cytokine associated with the pathogenesis of hepatic diseases. Metformin is an anti-diabetic drug used for the treatment of type 2 diabetes, and orphan nuclear receptor small heterodimer partner (SHP, also known as NR0B2), a transcriptional co-repressor, plays an important role in maintaining metabolic homeostasis. Here, we demonstrate that metformin-mediated activation of AMP-activated protein kinase (AMPK) increases SHP protein production and regulates IL-6-induced hepatic insulin resistance.

METHODS

We investigated metformin-mediated SHP production improved insulin resistance through the regulation of an IL-6-dependent pathway (involving signal transducer and activator of transcription 3 [STAT3] and suppressor of cytokine signalling 3 [SOCS3]) in both Shp knockdown and Shp null mice.

RESULTS

IL-6-induced STAT3 transactivation and SOCS3 production were significantly repressed by metformin, adenoviral constitutively active AMPK (Ad-CA-AMPK), and adenoviral SHP (Ad-SHP), but not in Shp knockdown, or with the adenoviral dominant negative form of AMPK (Ad-DN-AMPK). Chromatin immunoprecipitation (ChIP), co-immunoprecipitation (Co-IP) and protein localisation studies showed that SHP inhibits DNA binding of STAT3 on the Socs3 gene promoter via interaction and colocalisation within the nucleus. Upregulation of inflammatory genes and downregulation of hepatic insulin signalling by acute IL-6 treatment were observed in wild-type mice but not in Shp null mice. Finally, chronic IL-6 exposure caused hepatic insulin resistance, leading to impaired insulin tolerance and elevated gluconeogenesis, and these phenomena were aggravated in Shp null mice.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that SHP upregulation by metformin may prevent hepatic disorders by regulating the IL-6-dependent pathway, and that this pathway can help to ameliorate the pathogenesis of cytokine-mediated metabolic dysfunction.

Sequence analysis of the major piroplasm surface protein gene of benign bovine Theileria parasites in east Asia

Relatively benign Theileria parasites are widespread among cattle in East Asia. Although the parasites are presumed to be of the Theileria sergenti/Theileria buffeli/Theileria orientalis group, their taxonomic status and epidemiology have not been well defined. In the present study, theilerial DNA samples were collected from various East Asian countries, including Japan, Korea, Taiwan, and China. DNA sequences encoding a major piroplasm surface protein were amplified by polymerase chain reaction, followed by cloning into a plasmid vector. More than 20 DNA clones derived from parasite DNA of a single infected animal were examined for their restriction-fragment-length polymorphism, showing that they were classified into four major types. Sequence analysis revealed six types of DNA sequences encoding major piroplasm surface protein with homologies of between 75 and 91%. Of the six sequences, four were identical to those previously reported, while the other two appeared to be new sequences. Among the DNA clones derived from a single infected animal, two to three distinct sequences were often found. Phylogenetic analysis of the six major piroplasm surface protein sequences indicates that five of the six are closely related to each other, and that all are distantly related to the homologous genes of Theileria annulata and Theileria parva. The results suggest that, in addition to those described as T. sergenti/T. buffeli/T. orientalis, there may be some undefined Theileria species distributed in East Asia, and that many cattle are infected with mixed populations of geographically variable Theileria parasites.

Fractional flow reserve versus angiography-guided strategy in acute myocardial infarction with multivessel disease: a randomized trial

AIMS

In patients with acute myocardial infarction (MI) and multivessel coronary artery disease, percutaneous coronary intervention (PCI) of non-infarct-related artery reduces death or MI. However, whether selective PCI guided by fractional flow reserve (FFR) is superior to routine PCI guided by angiography alone is unclear. The current trial sought to compare FFR-guided PCI with angiography-guided PCI for non-infarct-related artery lesions among patients with acute MI and multivessel disease.

METHODS AND RESULTS

Patients with acute MI and multivessel coronary artery disease who had undergone successful PCI of the infarct-related artery were randomly assigned to either FFR-guided PCI (FFR ≤0.80) or angiography-guided PCI (diameter stenosis of >50%) for non-infarct-related artery lesions. The primary end point was a composite of time to death, MI, or repeat revascularization. A total of 562 patients underwent randomization. Among them, 60.0% underwent immediate PCI for non-infarct-related artery lesions and 40.0% were treated by a staged procedure during the same hospitalization. PCI was performed for non-infarct-related artery in 64.1% in the FFR-guided PCI group and 97.1% in the angiography-guided PCI group, and resulted in significantly fewer stent used in the FFR-guided PCI group (2.2 ± 1.1 vs. 2.5 ± 0.9, P < 0.001). At a median follow-up of 3.5 years (interquartile range: 2.7-4.1 years), the primary end point occurred in 18 patients of 284 patients in the FFR-guided PCI group and in 40 of 278 patients in the angiography-guided PCI group (7.4% vs. 19.7%; hazard ratio, 0.43; 95% confidence interval, 0.25-0.75; P = 0.003). The death occurred in five patients (2.1%) in the FFR-guided PCI group and in 16 patients (8.5%) in the angiography-guided PCI group; MI in seven (2.5%) and 21 (8.9%), respectively; and unplanned revascularization in 10 (4.3%) and 16 (9.0%), respectively.

CONCLUSION

In patients with acute MI and multivessel coronary artery disease, a strategy of selective PCI using FFR-guided decision-making was superior to a strategy of routine PCI based on angiographic diameter stenosis for treatment of non-infarct-related artery lesions regarding the risk of death, MI, or repeat revascularization.

Na,K-ATPase mRNA levels and plaque load in Alzheimer's disease

The expression of Na,K-ATPase alpha 1- and alpha 3-mRNAs was analyzed by in situ hybridization in the superior frontal cortex and cerebellum of brains from five Alzheimer's disease (AD), five nondemented age-matched, and three young control subjects. Brains with well-preserved RNA, tested by Northern hybridization of immobilized RNA with [32P]-labeled human beta-actin riboprobe, were chosen for analysis. In situ hybridization was performed on formalin-fixed, 5 microns-thick Paraplast sections with [35S]-labeled riboprobes prepared by in vitro transcription of the respective linearized clones: a 537-bp EcoRI-PstI fragment of alpha 1-cDNA and a 342-bp PstI-EcoRI fragment of alpha 3-cDNA. In cortex, grains related to mRNA were measured by density per unit area in five cortical columns separated by 1.0-1.2 cm in each of two adjacent sections. Each cortical column of 180-micron width was divided into four depths orthogonal to the pial surface between the pia and the white matter. Amyloid plaques were counted in the same regions of adjacent sections. In addition, alpha 3-mRNA grain clusters over individual pyramidal neurons within depth 4 were analyzed. We found the following significant changes (p < 0.05): 1. Increases in total alpha 1-mRNA by 13-19% in AD compared to young and by 7-12% in AD compared to age-matched controls. 2. Decrease in total alpha 3-mRNA by 31-38% in AD compared to young and age-matched controls. 3. Decrease in alpha 3-mRNA content over individual pyramidal perikarya by 14% in normal aged brains without plaques compared to young controls, and by 44% in AD relative to young controls and by 35% compared to age-matched controls. No significant difference (p < 0.2) was found with respect to alpha 1- or alpha 3-mRNA in cerebellar cortex or individual Purkinje cells among any of the groups. In addition, there was a trend toward an inverse correlation between the levels of alpha 3-mRNA and of diffuse plaques, but not of neuritic plaques, in AD cases.

IN CONCLUSION

1. The increases in alpha 1-mRNA in AD may be related to an increased reactive gliosis. 2. The declines in alpha 3-mRNA per individual neuron found in normal aging occur prior to the formation of diffuse plaques and are greatly accelerated in AD. 3. The declines in alpha 3-mRNA per neuron found in normal aging may predispose to or potentiate AD pathogenesis.

Mechanical properties of human pericardium. Differences in viscoelastic response when compared with canine pericardium

Whereas most experiments on the mechanical function of the pericardium have been performed on dogs, very little is known about the applicability of those data to humans. To examine the tensile viscoelastic properties of fresh human pericardium, we have used the methods from our previous study of canine pericardium. Although the mechanical responses of canine and human pericardium were qualitatively similar, human pericardium displayed a significantly greater viscous character. Human pericardium was 7.3 times thicker than canine pericardium, but was more extensible in stress-strain tests, with lower stiffness at a given strain. The static (elastic) stiffness of human pericardium seems identical to that of canine pericardium; lower stiffness per unit thickness of the human tissue at predicted physiological stresses was almost exactly compensated by the greater wall thickness. This effect was also seen in data on fracture strength and stiffness. However, human pericardium displayed greater viscous responses than the canine tissue. This was seen in doubled cyclic hysteresis losses, and greater stress relaxation and creep. Our results suggest that experiments on the viscoelastic properties of canine pericardium may not be directly applicable to humans, especially where dynamic mechanical properties are most important: i.e., in studies of ventricular function and the time-course of pericardial effusions.