Heat shock transcription factor 1-associated expression of slow myosin heavy chain in mouse soleus muscle in response to unloading with or without reloading

AIM

The effects of heat shock transcription factor 1 (HSF1) deficiency on the fibre type composition and the expression level of nuclear factor of activated T cells (NFAT) family members (NFATc1, NFATc2, NFATc3 and NFATc4), phosphorylated glycogen synthase kinase 3α (p-GSK3α) and p-GSK3β, microRNA-208b (miR-208b), miR-499 and slow myosin heavy chain (MyHC) mRNAs (Myh7 and Myh7b) of antigravitational soleus muscle in response to unloading with or without reloading were investigated.

METHODS

HSF1-null and wild-type mice were subjected to continuous 2-week hindlimb suspension followed by 2- or 4-week ambulation recovery.

RESULTS

In wild-type mice, the relative population of slow type I fibres, the expression level of NFATc2, p-GSK3 (α and β), miR-208b, miR-499 and slow MyHC mRNAs (Myh7 and Myh7b) were all decreased with hindlimb suspension, but recovered after it. Significant interactions between train and time (the relative population of slow type I fibres; P = 0.01, the expression level of NFATc2; P = 0.001, p-GSKβ; P = 0.009, miR-208b; P = 0.002, miR-499; P = 0.04) suggested that these responses were suppressed in HSF1-null mice.

CONCLUSION

HSF1 may be a molecule in the regulation of the expression of slow MyHC as well as miR-208b, miR-499, NFATc2 and p-GSK3 (α and β) in mouse soleus muscle.

The Biological Properties of a Novel Ethyl Methacrylate Resin

A novel ethyl methacrylate (EMA) resin was developed to overcome the tissue, organ and systemic damage associated with the residual monomer of conventional methyl methacrylate (MMA) resin bone cement. EMA resin is a chemical/ photopolymerizable material and is easy to handle during clinical procedures. The biocompatibility of EMA was evaluated in accordance with ISO10993-6. No inflammatory response was observed 1 and 9 weeks after implantation in the dorsal subcutaneous tissue of ddY mice. EMA resin also demonstrated better biocompatibility when compared with conventional bone cements. Poly-l-lactic acid (PLLA) was used as a carrier for bone morphogenetic protein (BMP) and added to the EMA slurry. The EMA-PLLA composite membrane was sticky and BMP readily adhered to its surface. The EMA-PLLA-BMP composite membrane induced new bone formation, the new bone growing in the shape of the EMA in the thigh muscle pouch of ddY mice. This novel EMA resin has many potential clinical applications.

Oncoplastic breast conserving surgery: Volume replacement vs. volume displacement

Oncoplastic breast conserving surgery (BCS) has emerged as a third option between conventional BCS and mastectomy. Oncoplastic BCS includes two fundamentally different approaches: volume replacement and volume displacement. The former involves partial mastectomy and immediate reconstruction of the breast with the transposition of autologous tissue from elsewhere, while the latter involves partial mastectomy and using the remaining breast tissue to fill the defect resulting from extirpation of the tumor. There are several benefits associated with oncoplastic BCS. First, it allows partial mastectomy without cosmetic penalties, and can achieve better cosmetic outcomes than total mastectomy with immediate breast reconstruction. Second, it avoids the need for total mastectomy in an increasing number of patients without compromising local control. Third, partial breast reconstruction is less extensive and has fewer complications than conventional procedures. Partial mastectomy and partial breast reconstruction can be carried out either simultaneously as a one-stage procedure, or using a two-stage approach. Although patients prefer a one-stage procedure, it requires intraoperative confirmation of complete tumor excision using frozen-section analysis. Moreover, oncoplastic BCS requires combined skills, knowledge, and understanding of both oncological and plastic surgeries, which may be optimally achieved by an oncoplastic surgeon.

Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice

AIM

Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated.

METHODS

Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia.

RESULTS

Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle.

CONCLUSION

Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway.

Transcatheter Aortic Valve Implantation Experience with SAPIEN 3

Based on randomized trials with first generation devices, transcatheter aortic valve replacement (TAVI) has been included into the treatment strategy for high-risk and inoperable patients with severe aortic stenosis. Procedural complications remain a concern with TAVI, including stroke, vascular complications, paravalvular leak (PVL) and conduction disturbances. Addressing these limitations will support TAVI use in lower risk populations. This review discussed features and most recent clinical evidence of the new balloon-expandable THV (SAPIEN 3, Edwards Lifescience, Irvine, CA, USA).

Successful active immunization using a hepatitis B virus vaccination protocol for a recipient with hepatitis B core antibody-positive liver graft

INTRODUCTION

Donor shortages occasionally necessitate the use of hepatic allografts from hepatitis B core antibody-positive (HBcAb+) donors, with an attendant risk of post-transplantation hepatitis B virus (HBV) infection. The aim of the present study was to develop and evaluate a protocol of active immunization for prevention of post-transplantation de novo HBV infection in patients receiving liver grafts from HBcAb+ donors.

PATIENTS AND METHODS

Ten patients who had received HBcAb+ liver grafts at Shinshu University Hospital between October 1996 and December 2012 were enrolled. All the recipients were negative for HBV serological tests, and HBV-DNA. Hepatitis B immunoglobulin (HBIG) was given routinely in the peritransplantation and post-transplantation periods, without antiviral drugs. Subcutaneous vaccination with recombinant HBV was given at a dosage of 20 μg in adults and 5 μg in children concomitant with HBIG until acquisition of active immunization. The timing to start HBV vaccination was dependent on the condition of the patient.

RESULTS

The median follow-up period after liver transplantation was 140 months, and the median period after transplantation until the start of vaccination was 7.0 months. Nine patients (90%) acquired active immunity after a median number of 4 (range, 2-13) vaccinations (hepatitis B surface antibody >300 mIU/mL for 1 year, or >100 mIU/mL thereafter), and did not require HBIG administration thereafter. None had any side effects of HBV vaccination or developed hepatitis B infection during the study period. Four fast responders who achieved antibody high titers by active immunization within 9 months received pretransplantation vaccinations, whereas 5 slow responders did not.

CONCLUSIONS

Our vaccination protocol provides a new effective strategy for prevention of de novo hepatitis B infection after liver transplantation in recipients with HBcAb+ liver grafts. Pretransplantation HBV vaccination was helpful for the post-transplantation vaccine response.

Computed diffusion-weighted MRI for prostate cancer detection: the influence of the combinations of b-values

OBJECTIVE

To evaluate the influence of the combinations of b-values on computed diffusion-weighted images (cDWIs) for prostate cancer (PCa) detection at b = 2000 s mm(-2).

METHODS

Diffusion-weighted imaging (DWIs) for 31 patients with PCa (65.2 ± 7.1 years) were obtained pre-operatively at different b-values (0, 100, 500, 1000 and 2000 s mm(-2)) on a 3-T MRI. cDWIs at b = 2000 were generated by using six b-value combinations: 0-100 s mm(-2) (cDWI0-100); 0-500 s mm(-2) (cDWI0-500); 100-500 s mm(-2) (cDWI100-500); 0-1000 s mm(-2) (cDWI0-1000); 100-1000 s mm(-2) (cDWI100-1000); and 500-1000 s mm(-2) (cDWI500-1000). These cDWIs and measured DWIs with b = 2000 s mm(-2) (mDWI2000) were evaluated in this setting. To assess image quality for each DWI, contrast ratios (CRs) of cancerous and non-cancerous lesions were evaluated. To compare the detectability of PCa for each DWI, receiver operating characteristic analysis was used.

RESULTS

CRs of all cDWIs were significantly higher than those of mDWI2000 (p < 0.05). Areas under the curve of cDWI0-100 (0.62) and cDWI0-500 (0.65) were significantly smaller (p < 0.05) than those of others (cDWI100-500, 0.72; cDWI0-1000, 0.73; cDWI100-1000, 0.71; cDWI500-1000, 0.74; mDWI2000, 0.72).

CONCLUSION

The combinations of b-values influenced image quality and diagnostic ability of cDWIs for PCa detection. The combinations of b ≥ 100 and b ≥ 500 s mm(-2), as well as b = 0 and b = 1000 s mm(-2), were optimal in this study.

ADVANCES IN KNOWLEDGE

For generating the useful cDWI for PCa detection, radiologists should take care of the combination of b-values when including low b-values.

MDGRAPE-4: a special-purpose computer system for molecular dynamics simulations

We are developing the MDGRAPE-4, a special-purpose computer system for molecular dynamics (MD) simulations. MDGRAPE-4 is designed to achieve strong scalability for protein MD simulations through the integration of general-purpose cores, dedicated pipelines, memory banks and network interfaces (NIFs) to create a system on chip (SoC). Each SoC has 64 dedicated pipelines that are used for non-bonded force calculations and run at 0.8 GHz. Additionally, it has 65 Tensilica Xtensa LX cores with single-precision floating-point units that are used for other calculations and run at 0.6 GHz. At peak performance levels, each SoC can evaluate 51.2 G interactions per second. It also has 1.8 MB of embedded shared memory banks and six network units with a peak bandwidth of 7.2 GB s(-1) for the three-dimensional torus network. The system consists of 512 (8×8×8) SoCs in total, which are mounted on 64 node modules with eight SoCs. The optical transmitters/receivers are used for internode communication. The expected maximum power consumption is 50 kW. While MDGRAPE-4 software has still been improved, we plan to run MD simulations on MDGRAPE-4 in 2014. The MDGRAPE-4 system will enable long-time molecular dynamics simulations of small systems. It is also useful for multiscale molecular simulations where the particle simulation parts often become bottlenecks.

Tetrodotoxin-Medicated Delay in Aconitine Toxicity: A Murder in Okinawa

Aconite (wolfsbane) plants, which belong to the genus Aconitum (Ranunculaceae family), contain highly toxic alkaloids, including aconitine, mesaconitine, hypaconitine, and jesaconitine, in all of their parts. The relevance of this plant material is illustrated by the case of a Japanese female who died suddenly in 1986 and was autopsied in Okinawa by the author. The detection in 1987 of Aconitum alkaloids in her blood using gas chromatography/selected ion monitoring (GC/SIM), which was newly developed for this case, demonstrated that she had died from aconite poisoning.