230 research outputs found
Atomic-Number (Z)-Correlated Atomic Sizes for Deciphering Electron Microscopic Molecular Images
With the advent of atomic-resolution transmission electron microscopy
(AR-TEM) achieving sub-{\AA}ngstrom image resolution and submillisecond time
resolution, an era of visual molecular science where chemists can visually
study the time evolution of molecular motions and reactions at atomistic
precision has arrived. However, the appearance of experimental TEM images often
differs greatly from that of conventional molecular models, and the images are
difficult to decipher unless we know in advance the structure of the specimen
molecules. The difference arises from the fundamental design of the molecular
models that represent atomic connectivity and/or the electronic properties of
molecules rather than the nuclear charge of atoms and electrostatic potentials
that are felt by the e-beam in TEM imaging. We found a good correlation between
the atomic number (Z) and the atomic size seen in TEM images when we consider
shot noise in digital images. We propose here Z-correlated (ZC) atomic radii
for modeling AR-TEM images of single molecules and ultrathin crystals, with
which we can develop a good estimate of the molecular structure from the TEM
image much more easily than with conventional molecular models. Two parameter
sets were developed for TEM images recorded under high-noise (ZCHN) and
low-noise (ZCLN) conditions. The new molecular models will stimulate the
imaginations of chemists planning to use AR-TEM for their research.Comment: 27 pages, 6 figure
Liver transplantation in a patient with hereditary haemorrhagic telangiectasia and pulmonary hypertension
Hereditary haemorrhagic telangiectasia or Rendu-Osler-Weber syndrome is a systemic vascular disease with autosomal dominant inheritance, mucocutaneous telangiectasia, and repeated nasal bleeding due to vascular abnormalities. Hereditary haemorrhagic telangiectasia may occasionally lead to complications, including arteriovenous malformations and pulmonary hypertension. We present a case of a 52-year-old female patient with hereditary haemorrhagic telangiectasia who was referred to our hospital for treatment of pulmonary hypertension. She had been diagnosed with hereditary haemorrhagic telangiectasia during adolescence and was being followed up. Six months prior to presentation, she had undergone coil embolization for pulmonary haemorrhage due to pulmonary arteriovenous malformations. She was in World Health Organization functional class IV, with a mean of pulmonary arterial pressure of 38 mmHg, a pulmonary capillary wedge pressure of 10 mmHg, and a right atrial pressure of 22 mmHg. A contrast-enhanced computed tomography angiography showed large arteriovenous malformations in the liver. Right heart catheterization revealed an increase in oxygen saturation in the inferior vena cava between the supra- and infra-hepatic veins, low pulmonary vascular resistance, and high right atrial pressure. Hence, she was diagnosed with hereditary haemorrhagic telangiectasia with pulmonary hypertension due to major arteriovenous shunt resulting from arteriovenous malformations in the liver. Therefore, we considered liver transplantation as an essential treatment option. She underwent cadaveric liver transplantation after a year resulting in dramatic haemodynamic improvement to World Health Organization functional class I. Liver transplantation is a promising treatment in patients with hereditary haemorrhagic telangiectasia and pulmonary hypertension resulting from arteriovenous shunt caused by arteriovenous malformations in the liver
The number of circulating CD34-positive cells is an independent predictor of coronary artery calcification progression: Sub-analysis of a prospective multicenter study
Background: Decreases in circulating CD34-positive cells are associated with increases in cardiovascular events. We investigated the association between the number of CD34-positive cells and the progression of coronary artery calcification (CAC), a marker of atherosclerosis, in patients with hypercholesteremia under statin therapy in a sub-analysis of a multicenter study.
Methods: In the principal study, patients with CAC scores of 1ā999 were treated with pitavastatin. Measurement of CAC by non-enhanced computed tomography and a blood test were performed at baseline and at 1-year follow-up. Patients were divided into two groups: CAC progression (change in CAC score > 0) and non-progression. The number of circulating CD34-positive cells was counted using flow cytometry.
Results: A total of 156 patients (mean age 67 years, 55% men) were included in this sub-analysis. CD34 positive cell numbers at baseline as a continuous variable was inversely correlated with annual change in the log-transformed CAC score (r = ā0.19, p = 0.02). When patients were divided into high and low CD34 groups based on the median value of 0.8 cells/Ī¼L, the adjusted change in CAC score in the low-CD34 group was significantly greater than that in the high-CD34 group (54.2% vs. 20.8%, respectively, p = 0.04). In multiple logistic analysis, a low CD34-positive cell number was an independent predictor of CAC progression, with an odds ratio of 2.88 (95% confidence interval 1.28ā6.49, p = 0.01).
Conclusions: Low numbers of CD34-positive cells are associated with CAC progression in patients with hypercholesterolemia under statin therapy. The number of CD34-positive cells may help to identify patients at increased cardiovascular risk
Efficacy and Safety of Early Intravenous Landiolol on Myocardial Salvage in Patients with ST-segment Elevation Myocardial Infarction before Primary Percutaneous Coronary Intervention: A Randomized Study
Early treatment with an oral Ī²-blocker is recommended in patients with a ST-segmentāelevation myocardial infarction (STEMI). In this multicenter study, we evaluated the effects of a continuous administration of landiolol, an ultrashort-acting Ī²-blocker, before primary percutaneous coronary intervention (PCI) on myocardial salvage and its safety in STEMI patients. A total of 47 Japanese patients with anterior or lateral STEMI undergoing a primary PCI within 12 h of symptom onset were randomized to receive intravenous landiolol (started at 3 Ī¼g/min/kg dose and continued to a total of 50 mg; n=23) or not (control; n=24). Patients with Killip class III or more were excluded. The primary outcome was the myocardial salvage index on cardiac magnetic resonance imaging (MRI) performed 5-7 days after the PCI. Cardiac MRI was performed in 35 patients (74%). The myocardial salvage index in the landiolol group was significantly greater than that in the control group (44.4Ā±14.6% vs. 31.7Ā±18.9%, respectively; p=0.04). There were no significant differences in adverse events at 24 h between the landiolol and control groups. A continuous administration of landiolol before a primary PCI may increase the degree of myocardial salvage without additional hemodynamic adverse effects within the first 24 h after STEMI
Impurity-induced magnetic order in the mixture of two spin gap systems (CH3)2CHNH3CuCl3 and (CH3)2CHNH3CuBr3
The ground state of the solid solution of the two spin gap systems
(CH3)2CHNH3CuCl3 and (CH3)2CHNH3CuBr3 has been investigated by 1H-NMR. The
existence of a magnetic ordering in the sample with the Cl-content x=0.85 was
clearly demonstrated by a drastic splitting in a resonance line at low
temperatures below TN=13.5K. The observed NMR spectra in the ordered state was
qualitatively consistent with the simple antiferromagnetic state.Comment: QuBS200
Therapeutic potential of PRL-3 targeting and clinical significance of PRL-3 genomic amplification in gastric cancer
<p>Abstract</p> <p>Background</p> <p>Phosphatase of regenerating liver-3 (PRL-3) has deserved attention as a crucial molecule in the multiple steps of metastasis. In the present study, we examined the mechanisms regulating PRL-3 expression, and assessed the clinical potential of PRL-3-targeted therapy in gastric cancer.</p> <p>Methods</p> <p>PRL-3 genomic amplification was analyzed using quantitative-polymerase chain reaction and/or fluorescence in situ hybridization in 77 primary gastric tumors. The anticancer activity of PRL-3 inhibitor (1-4-bromo-2-benzylidene rhodanine) treatment was evaluated against cancer cells with different genetic and expression status.</p> <p>Results</p> <p>PRL-3 genomic amplification was closely concordant with high level of its protein expression in cell lines, and was found in 20% (8/40) among human primary tumors with its expression, which were all stage III/IV disease (40%, 8/20), but in none (0/37) among those without expression. Additionally, PRL-3 genomic amplification was associated with metastatic lymph node status, leading to advanced stage and thereby poor outcomes in patients with lymph node metastasis (<it>P </it>= 0.021). PRL-3 small interfering RNA robustly repressed metastatic properties, including cell proliferation, invasion, and anchorage-independent colony formation. Although neither PRL-3 genomic amplification nor expression level was responsible for the sensitivity to PRL-3 inhibitor treatment, the inhibitor showed dose-dependent anticancer efficacy, and remarkably induced apoptosis on all the tested cell lines with PRL-3 expression.</p> <p>Conclusions</p> <p>We have for the first time, demonstrated that PRL-3 genomic amplification is one of the predominant mechanisms inducing its expression, especially in more advanced stage, and that PRL-3-targeted therapy may have a great potential against gastric cancer with its expression.</p
Incremental prognostic value of non-alcoholic fatty liver disease over coronary computed tomography angiography findings in patients with suspected coronary artery disease
AimsćThis study aimed to investigate additional risk stratification benefits of hepatic steatosis (HS) concurrently assessed during coronary computed tomography angiography (CTA) in a large patient cohort with suspected stable coronary artery disease (CAD).
Methods and resultsćIn this prospective study, 1148 Japanese outpatients without a history of CAD who underwent coronary CTA for suspected stable CAD (mean age 64āĀ±ā14āyears) were included. HS, defined on CT as a hepatic-to-spleen attenuation ratio of
ConclusionćIn patients with suspected stable CAD, concurrent evaluation of HS during coronary CTA enables more accurate detection of patients at higher risk of MACE
Extracellular poly(ADP-ribose) is a neurotrophic signal that upregulates glial cell line-derived neurotrophic factor (GDNF) levels inĀ vitro and inĀ vivo
editorial reviewedSynthesis of poly(ADP-ribose) (PAR) is catalyzed by PAR polymerase-1 (PARP-1) in neurons. PARP1 plays a role in various types of brain damage in neurodegenerative disorders. In neurons, overactivation of PARP-1 during oxidative stress induces robust PAR formation, which depletes nicotinamide adenine dinucleotide levels and leads to cell death. However, the role of the newly-formed PAR in neurodegenerative disorders remains elusive. We hypothesized that the effects of PAR could occur in the extracellular space after it is leaked from damaged neurons. Here we report that extracellular PAR (EC-PAR) functions as a neuroprotective molecule by inducing the synthesis of glial cell line-derived neurotrophic factor (GDNF) in astrocytes during neuronal cell death, both inĀ vitro and inĀ vivo. In primary rat astrocytes, exogenous treatment with EC-PAR produced GDNF but not other neurotrophic factors. The effect was concentration-dependent and did not affect cell viability in rat C6 astrocytoma cells. Topical injection of EC-PAR into rat striatum upregulated GDNF levels in activated astrocytes and improved pathogenic rotation behavior in a unilateral 6-hydroxydopamine model of Parkinson disease in rats. These findings indicate that EC-PAR acts as a neurotrophic enhancer by upregulating GDNF levels. This effect protects the remaining neurons following oxidative stress-induced brain damage, such as that seen with Parkinson disease
Prognostic value of non-alcoholic fatty liver disease for predicting cardiovascular events in patients with diabetes mellitus with suspected coronary artery disease: a prospective cohort study
Background
Risk stratification of cardiovascular events in patients with type 2 diabetes mellitus (T2DM) has not been established. Coronary artery calcium score (CACS) and non-alcoholic fatty liver disease (NAFLD) are independently associated with cardiovascular events in T2DM patients. This study examined the incremental prognostic value of NAFLD assessed by non-enhanced computed tomography (CT) in addition to CACS and Framingham risk score (FRS) for cardiovascular events in T2DM patients.
Methods
This prospective pilot study included 529 T2DM outpatients with no history of cardiovascular disease who underwent CACS measurement because of suspected coronary artery disease. NAFLD was defined on CT images as a liver:spleen attenuation ratioā
Results
Among 529 patients (61% men, mean age 65 years), NAFLD was identified in 143 (27%). Forty-four cardiovascular events were documented during a median follow-up of 4.4 years. In multivariate Cox regression analysis, NAFLD, CACS, and FRS were associated with cardiovascular events (hazard ratios and 95% confidence intervals 5.43, 2.82ā10.44, pā
Conclusions
NAFLD assessed by CT, in addition to CACS and FRS, could be useful for identifying T2DM patients at higher risk of cardiovascular events
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