Br-DIF-1 accelerates dimethyl sulphoxide-induced differentiation of P19CL6 embryonic carcinoma cells into cardiomyocytes

BACKGROUND AND PURPOSE

Stem cell transplantation therapy is a promising option for treatment of severe ischaemic heart disease. Dimethyl sulphoxide (DMSO) differentiates P19CL6 embryonic carcinoma cells into cardiomyocyte-like cells, but with low differentiation capacity. To improve the degree of this differentiation, we have assessed several derivatives of the differentiation-inducing factor-1 (DIF-1), originally found in the cellular slime mould Dictyostelium discoideum, on P19CL6 cells.

EXPERIMENTAL APPROACH

P19CL6 cells were cultured with each derivative and 1% DMSO for up to 16 days. Differentiation was assessed by measuring the number of beating and non-beating aggregates, and the expression of genes relevant to cardiac tissue. The mechanism of action was investigated using a T-type Ca(2+) channel blocker.

KEY RESULTS

Of all the DIF-1 derivatives tested only Br-DIF-1 showed any effects on cardiomyocyte differentiation. In the presence of 1% DMSO, Br-DIF-1 (0.3-3 µM) significantly and dose-dependently increased the number of spontaneously beating aggregates compared with 1% DMSO alone, by day 16. Expression of mRNA for T-type calcium channels was significantly increased by Br-DIF-1 + 1% DMSO compared with 1% DMSO alone. Mibefradil (a T-type Ca(2+) channel blocker; 100 nM) and a small interfering RNA for the T-type Ca(2+) channel both significantly decreased the beating rate of aggregates induced by Br-DIF-1 + 1% DMSO.

CONCLUSIONS AND IMPLICATIONS

Br-DIF-1 accelerated the differentiation, induced by 1% DMSO, of P19CL6 cells into spontaneously beating cardiomyocyte-like cells, partly by enhancing the expression of the T-type Ca(2+) channel gene.

Enhanced removal of sodium salts supported by in-situ catalyst synthesis in a supercritical water oxidation process

For practical applications of supercritical water oxidation to wastewater treatment, the deposition of inorganic salts in supercritical phase must be controlled to prevent a reactor from clogging. This study investigated enhanced removal of sodium salts with titanium particles, serving as a salt trapper and a catalyst precursor, and sodium recovery by sub-critical water. When Na(2)CO(3) was tested as a model salt, sodium removal efficiency was higher than theoretically maximum efficiency defined by Na(2)CO(3) solubility. The enhanced sodium removal resulted from in-situ synthesis of sodium titanate, which could catalyse acetic acid oxidation. The kinetics of sodium removal was described well by a diffusion mass-transfer model combined with a power law-type rate model of sodium titanate synthesis. Titanium particles showed positive effect on sodium removal in the case of NaOH, Na(2)SO(4) and Na(3)PO(4). However, they had negligible effect for NaCl and negative effect for Na(2)CrO(4), respectively. More than 99% of trapped sodium was recovered by sub-critical water except for Na(2)CrO(4). In contrast, sodium recovery efficiency remained less than 50% in the case of Na(2)CrO(4). Reused titanium particles showed the same performance for enhanced sodium removal. Enhanced salt removal supported by in-situ catalyst synthesis has great potential to enable both salt removal control and catalytic oxidation.

Myoglobin subfractions: abnormality in duchenne type of progressive muscular dystrophy

Human metmyoglobin was separated electrophoretically into four subfractions: Mb(1), Mb(2), Mb(3), and Mb(4), which divide into at least two biochemically independent groups: Mb(1) and Mb(2), and Mb(3), and Mb(4). In normal subjects, Mb(1) constituted the predominant component; Mb(2), Mb(3), and Mb(4) were the minor components in this descending order. In the Duchenne type of progressive muscular dystrophy, on the contrary, a remarkable decrease in Mb(1) and a concomitant increase in Mb(3) were observed. This unique abnormality in the relative distribution of myoglobin subfractions was recognized only in the Duchenne type and not in other types of progressive muscular dystrophy or in other myopathies.

Magnetic-field induced phase transitions in a weakly coupled s=1/2 quantum spin dimer system Ba3Cr2O8

By using bulk magnetization, electron spin resonance (ESR), heat capacity, and neutron scattering techniques, we characterize the thermodynamic and quantum phase diagrams of Ba3Cr2O8. Our ESR measurements indicate that the low field paramagnetic ground state is a mixed state of the singlet and the Sz=0 triplet for H perpendicular c. This suggests the presence of an intradimer Dzyaloshinsky-Moriya (DM) interaction with a DM vector perpendicular to the c axis.

Antiferromagnetic d-electron exchange via a spin-singlet pi-electron ground state in an organic conductor

Electron spin resonance reveals the spin behavior of conduction (pi) and localized (d) electrons in beta-(BDA-TTP)2MCl4 (M=Fe, Ga). Both the Ga3+(S=0) and Fe3+(S=5/2) compounds exhibit a metal-insulator transition at 113 K with the simultaneous formation of a spin-singlet ground state in the pi electron system of the donor molecules. The behavior is consistent with charge ordering in beta-(BDA-TTP)2MCl4 at the metal-insulator transition. At 5 K, the Fe3+ compound orders antiferromagnetically, even though the pi electrons, which normally would facilitate magnetic exchange, are localized nonmagnetic singlets.

[Surgical treatment of transposition of great arteries: the coronary buttons transfer using medially based trapdoor flaps]

The arterial switch operation (ASO) has become the primary surgical approach used for correction of transposition of the great arteries. All the prerequisites for a successful ASO were recognized in time and dealt with, which allowed general acceptation of the technique. We report on our technique for the procedure and the result to date. From January 1991 to January 2008, a total of 100 patients underwent ASO at our unit using medially-based trapdoor flap method. The neo-pulmonary artery (PA) was reconstructed using a single rectangular pericardial patch. The initial patient having intramural coronary artery died due to ischemic event after Aubert procedure. Three patients had re-right ventricular out flow tract repair (RVOTR) in a long-term follow-up period. There was no significant aortic insufficiency, no ischemic event and no lethal arrhythmia.

Efficacy of intravitreal bevacizumab for polypoidal choroidal vasculopathy

AIMS

The aim of the study was to assess the short-term efficacy of intravitreal injections of bevacizumab for polypoidal choroidal vasculopathy (PCV).

METHODS

Intravitreal bevacizumab (1 mg) was injected into 11 eyes of 11 patients with PCV in this retrospective, interventional case series. The main outcome measure was the change in the polypoidal vessels on indocyanine green angiography (IA) 3 months after injection. The foveal height determined by optical coherence tomography and the best-corrected visual acuity (BCVA) also were evaluated before and after treatment.

RESULTS

At baseline, subretinal fluid was observed in five eyes and a pigment epithelial detachment in eight eyes. The foveal height 1 month after injection decreased significantly (p = 0.023), but at 3 months, no significant decrease was observed, although an additional injection was administrated in five of 11 eyes. The IA at 3 months showed resolution of polyps in one eye but residual or enlarged lesions in the other ten eyes. The BCVA did not improve significantly, although the subjects had relatively good BCVA at baseline (mean 0.45).

CONCLUSION

Intravitreal injection of bevacizumab may reduce the fluid from PCV but seems to be ineffective for diminishing its choroidal vascular changes.

Pars plana vitrectomy with peripheral retinotomy after injection of preoperative intravitreal tissue plasminogen activator: a modified procedure to drain massive subretinal haemorrhage

AIMS

To report outcome of a modified procedure for draining massive subretinal haemorrhages (SRHs).

METHODS

The charts of eight consecutive eyes from eight patients with massive SRHs extending to the periphery and involving two or more quadrants with haemorrhagic and bullous retinal detachment were reviewed. Tissue plasminogen activator (tPA) was injected intravitreally 12-24 h preoperatively; vitrectomy was carried out with peripheral retinotomy, drainage of the SRH from the retinotomy using perfluorocarbon liquid and gas tamponade with prone positioning postoperatively.

RESULTS

The preoperative visual acuities ranged from light perception to 20/200. Most of the subretinal haematomas moved postoperatively to the vitreous cavity through the peripheral retinotomy using perfluorocarbon liquid. Residual SRHs were drained from the anterior chamber at the bedside after prone positioning overnight. SRH recurred in one eye 14 months postoperatively and was successfully retreated. No other serious complications developed. The final visual acuity improved in seven eyes (range 20/1000-20/60). Polypoidal lesions in choroidal vasculatures were present in three of seven patients.

CONCLUSIONS

The technique seems safe and effective for treating massive SRH. However, visual recovery is limited by the underlying macular pathology. Polypoidal choroidal vasculopathy, other than age-related macular degeneration, may be another cause of massive SRHs.

Intravitreal injection of bevacizumab for choroidal neovascularisation associated with pathological myopia

AIM

To assess the efficacy and safety of an intravitreal injection of bevacizumab (Avastin(R)) for myopic choroidal neovascularisation (mCNV).

METHODS

Intravitreal bevacizumab (1 mg) was injected into eight eyes of eight patients with mCNV in this non-randomised, interventional case series. The best-corrected visual acuity (BCVA) was measured and the optical coherence tomography (OCT) and fluorescein angiography findings were examined before and after treatment. The minimum follow-up time was 3 months.

RESULTS

The mean BCVA was 0.26 before treatment and 0.51 at the last visit (p = 0.009). The BCVA improved to two or more lines in six eyes (75%) and remained the same in two eyes (25%). Leakage from the mCNV on fluorescein angiography decreased in seven eyes (87.5%). The choroidal neovascularisation area on fluorescein angiography (p = 0.049) and the foveal thickness on OCT images decreased significantly (p = 0.027) after the treatment. No major complications developed.

CONCLUSION

Intravitreal injection of bevacizumab seems to be an effective and safe treatment for mCNV.

Within-day variability of whole-body and segmental bioelectrical impedance in a standing position

OBJECTIVE

To assess the variation in whole-body and segmental bioelectrical impedance measured in the standing position over the course of a day.

SUBJECTS

Sixteen healthy men aged 29.6 +/- 3.1 years participated in this study.

MEASUREMENT

Impedance between the hands (Z H-H), the feet (Z F-F), and the both hands and feet (Z H-F) was measured using a bioelectrical impedance analysis (BIA) data acquisition system at 500 microA and 50 kHz. Body weight, Z H-H, Z F-F and Z H-F were measured every 3 h from 0900 to 1800.

RESULTS

Body weight was slightly, but significantly, changed at 1200 (-0.4 +/- 0.4 kg, P < 0.05), 1500 (+0.4 +/- 0.3 kg, P < 0.05) and 1800 (-0.2 +/- 0.2 kg, P < 0.05) compared to their respective previous measurement values. Z H-H significantly increased (P < 0.05) and Z F-F significantly decreased (P < 0.05) over the course of a day. The mean changes in impedance from 0900 to 1800 were +27.2 Omega (Z H-H) and -31.8 Omega (Z F-F), respectively. There were no changes in Z H-H at 1500 and in Z F-F at 1800 compared to their respective previous measurement values. The Z H-F value did not change significantly between 0900 and 1800.

CONCLUSION

Although changes in standing whole-body impedance during the day are small, arm and leg segmental impedance measurements change significantly. Therefore, it is necessary to measure the impedance at regularly scheduled times when evaluating whole-body %fat or body water content using the segmental BIA method.

A constitutive mutation, phoT, of the repressible acid phosphatase synthesis with inability to transport inorganic phosphate in Saccharomyces cerevisiae

Wild-type cells of Saccharomyces cerevisiae cultivated in low-Pi medium actively accumulate inorganic phosphate (Pi), while the same cells cultivated in high-Pi medium do not. A recessive constitutive mutant (phoT), for repressible acid phosphatase (EC 3.1.3.2) synthesis, is described. It shows severely reduced potency of Pi uptake, while the recessive constitutive mutants, phoR and phoU, in the same system show wild-type potency as.