Theoretical study on excited states of bacteriochlorophyll a in solutions with density functional assessment

The excited-state properties of bacteriochlorophyll (BChl) a in triethylamine, 1-propanol, and methanol are investigated with the time-dependent density functional theory by using the quantum mechanical and molecular mechanical reweighting free energy self-consistant field method. It is found that no prevalent density functionals can reproduce the experimental excited-state properties, i.e., the absorption and reorganization energies, of BChl a in the solutions. The parameter μ in the range-separated hybrid functional is therefore optimized to reproduce the differences of the absorption energies in the solutions. We examine the origin of the differences of the absorption energies in the solutions and find that sensitive balance between contributions of structural changes and solute-solvent interactions determines the differences. The accurate description of the excitation with the density functional with the adjusted parameter is therefore essential to the understanding of the excited-state properties of BChl a in proteins and also the mechanism of the photosynthetic systems.

Aortic transgraft hemorrhage after intravenous tissue plasminogen activator therapy in patients with acute ischemic stroke

BACKGROUND

The safety of intravenous recombinant tissue plasminogen activator (IV tPA) therapy for patients with an aortic aneurysm or undergoing aortic graft replacement has not been established. We evaluated the incidence, bleeding site, coagulation factors, and clinical outcomes of patients treated with IV tPA for acute stroke.

METHODS

Between October 2005 and May 2013, 394 ischemic stroke patients were treated in our stroke center with IV tPA. Among these patients, we investigated those who had a history of aortic aneurysm with or without aortic graft replacement before IV tPA therapy and underwent computed tomography imaging. We compared the levels of D-dimer and hemoglobin (Hb) around IV tPA therapy between the patients with and without tPA-associated periaortic bleeding.

RESULTS

Seven patients with a history of aortic aneurysm (3 men; mean age: 80.4 years) were examined; 3 had undergone aortic graft replacement, and 2 had experienced tPA-associated bleeding around vascular grafts. The serum D-dimer levels in those with bleeding were only slightly higher before tPA than in those without (median: 10.5 vs. 1.5 μg/mL) but were elevated 1 day after tPA (107.4 vs. 8.6 μg/mL). The Hb levels 2 days after tPA were comparable with those before tPA (11.9 vs. 11.8 g/dL) but were lower in the patients with bleeding than in those without (8.5 vs. 11.7 g/dL). Surgical intervention was not required, although 1 patient required blood transfusion.

CONCLUSIONS

Our analysis provides reassurance regarding the risk of IV tPA therapy in patients undergoing aortic graft replacement.

[Role of cardiac computed tomography in cardiac surgery]

In the field of cardiovascular surgery, cardiac computed tomography (CT) has served an important role in association with the improvement of the spatial and temporal resolution. Because CT angiography (CTA) provides more available information than plain CT, CTA has been increasingly used to access the coronary arteries and graft patency after coronary artery bypass grafting (CABG). Recently, minimally invasive cardiac surgeries, including CABG with left mini-thoracotomy and mitral valve surgery with right mini-thoracotomy, are revived, which requires preoperative CTA to make a strategy of incision placement on the basis of anatomical relationship between the target structure of the heart and the thorax. In Japan, transcatheter aortic valve implantation (TAVI) was approved in the late 2013, and is expected to be widely performed in the future. CTA is extremely useful for TAVI patients to determine the choice of the valve size and the surgical approach. CT provides many other valuable findings to us, but if we cannot fully leverage it in the daily cardiovascular surgery, its value is decreased. We have to acquire enough skill to maximize the performance of CT in the practical clinical setting.

Organized thrombus in pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension; imaging with cone beam computed tomography

PURPOSE

To assess the usefulness of cone-beam CT (CBCT) during pulmonary angiography for the evaluation of organized thrombus at segmental or subsegmental arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

MATERIALS AND METHODS

The segmental and/or subsegmental pulmonary arteries of 13 patients with CTEPH were evaluated by CBCT. We classified representative forms of organized thrombus into 4 types (type 1: webs, type 2: web and slits, type 3: slits, and type 4: narrowing or complete occlusion), and the distribution and frequency of the organized thrombus were evaluated. The relative detectability of these lesions using CBCT was compared with that in contrast-enhanced CT pulmonary angiography (CTPA).

RESULTS

Type 1 lesions were most frequently observed in both segmental (30/65 = 46 %) and subsegmental branches (72/156 = 46 %). Type 2 lesions were relatively less frequent than type 1, but subsegmental branches were frequently involved (29/156 = 19 %). Type 3 lesions observed as a thin flap in 9/156 subsegmental branches (6 %). Comparing with CTPA, all 40 lesions in segmental branches were detectable in CTPA, whereas only 62 lesions among 90 lesions (69 %) in subsegmental branches could be observed by CTPA.

CONCLUSION

CBCT is found to be useful for the treatment planning of balloon pulmonary angioplasty distal to segmental arteries.

Prevalence of dural ectasia in Loeys-Dietz syndrome: comparison with Marfan syndrome and normal controls

BACKGROUND AND PURPOSE

Dural ectasia is well recognized in Marfan syndrome (MFS) as one of the major diagnostic criteria, but the exact prevalence of dural ectasia is still unknown in Loeys-Dietz syndrome (LDS), which is a recently discovered connective tissue disease. In this study, we evaluated the prevalence of dural ectasia in LDS according by using qualitative and quantitative methods and compared our findings with those for with MFS and normal controls.

MATERIAL AND METHODS

We retrospectively studied 10 LDS (6 males, 4 females, mean age 36.3 years) and 20 MFS cases (12 males, 8 females, mean age 37.1 years) and 20 controls (12 males, 8 females, mean age 36.1 years) both qualitatively and quantitatively using axial CT images and sagittal multi-planar reconstruction images of the lumbosacral region. For quantitative examination, we adopted two methods: method-1 (anteroposterior dural diameter of S1> L4) and method-2 (ratio of anteroposterior dural diameter/vertebral body diameter>cutoff values). The prevalence of dural ectasia among groups was compared by using Fisher's exact test and the Tukey-Kramer test.

RESULTS

In LDS patients, the qualitative method showed 40% of dural ectasia, the quantitative method-1 50%, and the method-2 70%. In MFS patients, the corresponding prevalences were 50%, 75%, and 85%, and in controls, 0%, 0%, and 5%. Both LDS and MFS had a significantly wider dura than controls.

CONCLUSIONS

While the prevalence of dural ectasia varied depending on differences in qualitative and quantitative methods, LDS as well as MFS, showed, regardless of method, a higher prevalence of dural ectasia than controls. This finding should help the differentiation of LDS from controls.

Myocardial impairment detected by late gadolinium enhancement in hypertrophic cardiomyopathy: comparison with 99mTc-MIBI/tetrofosmin and 123I-BMIPP SPECT

PURPOSE

Myocardial fibrosis is considered to be an important factor in myocardial dysfunction and sudden cardiac death in hypertrophic cardiomyopathy (HCM). The purpose of this study was to compare myocardial fibrosis detected by late gadolinium enhancement (LGE) on cardiac MRI with myocardial perfusion and fatty acid metabolism assessed by single photon emission computed tomography in HCM.

MATERIALS AND METHODS

We retrospectively evaluated 20 consecutive HCM patients (female, 7; mean age, 53.4 years) who underwent LGE, technetium-99m methoxyisobutylisonitrile/tetrofosmin (99mTc-MIBI/tetrofosmin), and iodine-123 beta-methyl-iodophenylpentadecanoic acid (123I-BMIPP) imaging. We calculated the myocardium-to-lumen signal ratio (M/L) for LGE in 17 segments based on the American Heart Association statement. Scoring of 99mTc-MIBI/tetrofosmin (PI) and 123I-BMIPP (BM) was performed for each segment using a 5-point scale (0, normal; 4, highly decreased).

RESULTS

Nineteen of 20 patients (95%) and 153 of 340 segments (45%) showed LGE. M/Ls were 0.42±0.16, 0.55±0.17, and 0.65±0.24 in PI0/BM0, PI0/BM1-4 and PI1-4/BM1-4, respectively. All M/Ls were significantly higher than that of a normal control (0.34±0.14) (p<0.001).

CONCLUSIONS

Myocardial fibrosis in HCM can occur despite normal perfusion and fatty acid metabolism, and is more strongly associated with disorders of fatty acid metabolism than with perfusion abnormalities. M/L may be a useful indicator of disease severity.

Concerted hydrogen atom and electron transfer mechanism for catalysis by lysine-specific demethylase

We calculate the free energy profile for the postulated hydride transfer reaction mechanism for the catalysis of lysine demethylation by lysine-specific demethylase LSD1. The potential energy surface is obtained by using combined electrostatically embedded multiconfiguration molecular mechanics (EE-MCMM) and single-configuration molecular mechanics (MM). We employ a constant valence bond coupling term to obtain analytical energies and gradients of the EE-MCMM subsystem, which contains 45 quantum mechanics (QM) atoms and which is parametrized with density functional calculations employing specific reaction parameters obtained by matching high-level wave function calculations. In the MM region, we employ the Amber ff03 and TIP3P force fields. The free energy of activation at 300 K is calculated by molecular dynamics (MD) umbrella sampling on a system with 102,090 atoms as the maximum of the free energy profile along the reaction coordinate as obtained by the weighted histogram analysis method with 17 umbrella sampling windows. This yields a free energy of activation of only 10 kcal/mol, showing that the previously postulated direct hydride transfer reaction mechanism is plausible, although we find that it is better interpreted as a concerted transfer of a hydrogen atom and an electron.

Bone-destroying candida infection following left ventricular assist device explant

Infections associated with left ventricular assist devices (LVADs) constitute an important clinical issue because they are difficult to completely eradicate without removal of the LVAD itself and can sometimes be fatal. We encountered a case of extracorporeal LVAD-related candida infection in a patient who was successfully weaned from LVAD support. Although the patient appeared to have recovered from the infection, the patient was readmitted to our institute due to a relapse of candida infection 9 months after LVAD removal. Although the patient did not demonstrate any systemic sign of infection on admission, computed tomography images clearly showed that the residual apical cuff of the LVAD inflow cannula, which was infected with Candida albicans during the initial admission, resulted in re-infection that involved the chest wall with destruction of the adjacent rib.

The etiologic role of human papillomavirus in penile cancers: a study in Vietnam

Background:

We investigated the aetiologic role of human papillomavirus (HPV) in 120 penile squamous cell carcinomas (PSCCs) from Vietnam.

Methods:

Human papillomavirus DNA was detected by PCR using SPF10 primers and a primer set targeting HPV-16 E6. The INNO-LiPA HPV genotyping kit was used to determine genotype. Human papillomavirus-16 viral load and physical status were determined by real-time PCR. P16^INK4A protein expression was investigated by immunohistochemistry.

Results:

Human papillomavirus DNA was detected in 27 of 120 (23%) PSCCs. The most frequently detected genotype was HPV-16 (24 of 27 cases, 89%). In 16 of 18 (89%) HPV-16-positive cases, the HPV DNA was considered to be integrated into the host genome. The geometric mean of the HPV-16 viral load was 0.4 copies per cell. P16^INK4A overexpression was significantly related to PSCCs infected with high-risk HPV (P=0.018) and HPV-16 copy numbers (P<0.001).

Conclusion:

Human papillomavirus-16 DNA integration and p16^INK4A overexpression in high-risk HPV detected PSCCs suggested an aetiologic role of high-risk HPV in the development of PSCCs.

MUC1 enhances hypoxia-driven angiogenesis through the regulation of multiple proangiogenic factors

Pancreatic cancer is one of the most lethal malignancies due to its aggressive growth and rapid development of distant metastases. In this context, mucin 1 (MUC1) overexpression and hypoxia are frequently observed events. However, their functional relationship remains largely unknown. This study provides evidence that MUC1 is overexpressed by hypoxia and contributes to hypoxia-driven angiogenesis. Using the conditioned medium obtained from hypoxia-stressed AsPC1 cells treated with MUC1 siRNAs, we demonstrated that MUC1 enhanced the endothelial tube formation, proliferation and migration ability, which induced by hypoxia-conditioned medium (HCM). In addition, MUC1 was significantly induced by hypoxia, especially in the pancreatic cancer cells derived from metastatic tumors (AsPC1, HPAF2 or Capan1), and MUC1-cytoplasmic tail (MUC1-CT) accumulated in the nucleus under hypoxia. As noted in a previous report, MUC1-CT was recruited to genomic regions upstream of the connective tissue growth factor (CTGF) accompanied with β-catenin and p53, resulting in the hypoxic induction of CTGF. Moreover, hypoxia-induced MUC1 partially regulated two other hypoxia-inducible proangiogenic factors including vascular endothelial growth factor-A and platelet-derived growth factor-B. The neutralization assay revealed that endothelial tube formation induced by HCM was clearly suppressed by antibodies against these three factors, suggesting the importance of these factors in hypoxia-driven angiogenesis. In summary, this is the first report demonstrating a pivotal role of MUC1 in controlling the hypoxia-driven angiogenesis through the regulation of multiple proangiogenic factors in pancreatic cancer. Our findings provide the novel insights into the understanding of complex interactions between pancreatic cancer cells and tumor microenvironments.

Cerebral hemodynamic benefits after contralateral carotid artery stenting in patients with internal carotid artery occlusion

CEA contralateral to an ICA occlusion is considered a surgical risk, and CAS may be an alternative for these patients. Our goal was to examine whether CAS improves cerebral hemodynamics on the treated side and on the side of the ICA occlusion, on the basis of measurement of CBF and CVR by using SPECT. The subjects were 8 patients who underwent contralateral CAS. Resting CBF and CVR to acetazolamide were measured by using (123)I-IMP SPECT before and chronically (3-6 months) after CAS. Resting CBF was also measured immediately (<2 hours) after CAS by using (123)I-IMP SPECT. There were no significant differences in resting CBF in both hemispheres immediately after CAS. However, resting CBF and CVR both significantly increased in the chronic period in both hemispheres. Contralateral CAS in patients with ICA occlusion resulted in cerebral hemodynamic improvement on the treated side and on the side of ICA occlusion.

Synthesis and photophysical properties of dimethoxybis(3,3,3-trifluoropropen-1-yl)benzenes: compact chromophores exhibiting violet fluorescence in the solid state

Dimethoxybis(3,3,3-trifluoropropen-1-yl)benzenes were prepared through palladium-catalyzed double cross-coupling reactions of diiododimethoxybenzenes with CF(3)C≡CZnCl, followed by reduction of CF(3)C≡C groups with LiAlH(4) or H(2) in the presence of the Lindlar catalyst. The edges of the absorption spectra of 1,2-(MeO)(2)-4,5-(CF(3)CHC=CH)(2) benzenes 1 and 1,3-(MeO)(2)-4,6-(CF(3)CH=CH)(2) benzenes 2 in cyclohexane ranged from 348 to 360 nm, whereas the absorption spectra of 1,4-(MeO)(2)-2,5-[(E)-CF(3)CH=CH](2) benzene ((E)-3) ended at 406 nm. These findings indicate that the effective conjugation length of (E)-3 was significantly larger than those of 1 and 2. Consistently, 1 and 2 in cyclohexane exhibited fluorescence with emission maxima in the UV region, whereas (E)-3 in cyclohexane emitted violet light with an emission maximum at 407 nm. All the fluorescence spectra of 1-3 in various solvents redshifted as the solvent polarity increased. The photoluminescence of 1-3 in the solid states was also observed with emission maxima in the violet region. It is important to note that the quantum yields of (E)-3 in a neat thin film and in a doped polymer film were 0.37 and 0.49, respectively. Density functional theory calculations suggested that the fluorine atoms contribute to a slight extension of both the HOMOs and the LUMOs, as well as narrowing of the HOMO-LUMO gaps when compared with the corresponding fluorine-free analogues. In the case of (E)-3, it is suggested that the HOMO-LUMO transition includes charge transfer from the ethereal oxygen atoms to the C(sp(2))-CF(3) moieties.