[Survey on the Number and Percentage of MR Safety Labeling Changed for Implantable Medical Devices]

PURPOSE

The purposes of this study were to investigate the number and percentage of items that changed magnetic resonance (MR) safety information labeling for implantable medical devices (IMDs) and to confirm the importance of checking the latest MR safety information database (117 types and 10031 items).

METHODS

We investigated the number and percentage of MR safety labeling changed for IMDs in the MR safety information database as of December 2021 and August 2022.

RESULTS

IMDs of MR Safety Unlabeled decreased from 4116 items (41.1%) to 859 items (8.6%). IMDs of MR Conditional increased from 4141 items (41.3%) to 5896 items (58.8%).

CONCLUSIONS

Since there have been changes in the MR safety labeling for many IMDs, this study shows that it is important to confirm the latest MR safety information for IMDs.

Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst)  eV and 6463.7±0.3(stat)±0.1(syst)  eV, and widths to be 2.5±1.0(stat)±0.4(syst)  eV and 1.0±0.6(stat)±0.3(stat)  eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

Preparation status of missing-mass spectroscopy for 𝚵 hypernuclei with S-2S magnetic spectrometer

J-PARC E70 experiment measures the missing-mass of Ξ hypernuclei (12ΞBe) in Hadron Experimental Facility at J-PARC. We aim to reach the best missing-mass resolution of 2 MeV/c2 in FWHM with a new magnetic spectrometer S-2S. The high-resolution spectroscopy of Ξ hypernuclei will play an important role to understand the unknown ΞN interaction. The experiment will start at the beginning of 2023. This article presents the preparation status.

The effect of viscoelasticity in an airway closure model

The closure of a human lung airway is modeled as a pipe coated internally with a liquid that takes into account the viscoelastic properties of mucus. For a thick enough coating, the Plateau-Rayleigh instability blocks the airway by the creation of a liquid plug, and the pre-closure phase is dominated by the Newtonian behavior of the liquid. Our previous study with a Newtonian-liquid model demonstrated that the bifrontal plug growth consequent to airway closure induces a high level of stress and stress gradients on the airway wall, which is large enough to damage the epithelial cells, causing sub-lethal or lethal responses. In this study, we explore the effect of the viscoelastic properties of mucus by means of the Oldroyd-B and FENE-CR model. Viscoelasticity is shown to be very relevant in the post-coalescence process, introducing a second peak of the wall shear stresses. This second peak is related to an elastic instability due to the presence of the polymeric extra stresses. For high-enough Weissenberg and Laplace numbers, this second shear stress peak is as severe as the first one. Consequently, a second lethal or sub-lethal response of the epithelial cells is induced.

Development of a Searchable System to Confirm MR Imaging Safety Information for Implantable Medical Devices

The purpose of this study was to develop a searchable system to confirm magnetic resonance (MR) safety information of implantable medical devices (IMDs) to safely perform magnetic resonance imaging examinations. We labeled MR safety information for IMDs based on package insert descriptions and then categorized allowed MR conditions for IMDs. Finally, a searchable system was developed to use the database via the internet. This system enables efficient and accurate confirmation of MR safety information for IMDs.

Liquid plug formation in an airway closure model

The closure of a human lung airway is modeled as an instability of a two-phase flow in a pipe coated internally with a Newtonian liquid. For a thick enough coating, the Plateau-Rayleigh instability creates a liquid plug which blocks the airway, halting distal gas exchange. Owing to a bi-frontal plug growth, this airway closure flow induces high stress levels on the wall, which is the location of airway epithelial cells. A parametric numerical study is carried out simulating relevant conditions for human lungs, either in ordinary or pathological situations. Our simulations can represent the physical process from pre- to post-coalescence phases. Previous studies have been limited to pre-coalescence only. The topological change during coalescence induces a high level of stress and stress gradients on the epithelial cells, which are large enough to damage them, causing sub-lethal or lethal responses. We find that post-coalescence wall stresses can be in the range of 300% to 600% greater than pre-coalescence values, so introduce a new important source of mechanical perturbation to the cells.

Effects of surfactant on propagation and rupture of a liquid plug in a tube

Surfactant-laden liquid plug propagation and rupture occurring in lower lung airways are studied computationally using a front-tracking method. The plug is driven by an applied constant pressure in a rigid axisymmetric tube whose inner surface is coated by a thin liquid film. The evolution equations of the interfacial and bulk surfactant concentrations coupled with the incompressible Navier-Stokes equations are solved in the front-tracking framework. The numerical method is first validated for a surfactant-free case and the results are found to be in good agreement with the earlier simulations of Fujioka et al. (2008) and Hassan et al. (2011). Then extensive simulations are performed to investigate the effects of surfactant on the mechanical stresses that could be injurious to epithelial cells such as pressure and shear stress. It is found that the liquid plug ruptures violently to induce large pressure and shear stress on airway walls and even a tiny amount of surfactant significantly reduces the pressure and shear stress and thus improves cell survivability. However, addition of surfactant also delays the plug rupture and thus airway reopening.

Dominance of Tensor Correlations in High-Momentum Nucleon Pairs Studied by (p,pd) Reaction

The isospin character of p-n pairs at large relative momentum has been observed for the first time in the ^{16}O ground state. A strong population of the J,T=1,0 state and a very weak population of the J,T=0,1 state were observed in the neutron pickup domain of ^{16}O(p,pd) at 392 MeV. This strong isospin dependence at large momentum transfer is not reproduced by the distorted-wave impulse approximation calculations with known spectroscopic amplitudes. The results indicate the presence of high-momentum protons and neutrons induced by the tensor interactions in the ground state of ^{16}O.

Spectroscopy of Pionic Atoms in ^{122}Sn(d,^{3}He) Reaction and Angular Dependence of the Formation Cross Sections

We observed the atomic 1s and 2p states of π^{-} bound to ^{121}Sn nuclei as distinct peak structures in the missing mass spectra of the ^{122}Sn(d,^{3}He) nuclear reaction. A very intense deuteron beam and a spectrometer with a large angular acceptance let us achieve a potential of discovery, which includes the capability of determining the angle-dependent cross sections with high statistics. The 2p state in a Sn nucleus was observed for the first time. The binding energies and widths of the pionic states are determined and found to be consistent with previous experimental results of other Sn isotopes. The spectrum is measured at finite reaction angles for the first time. The formation cross sections at the reaction angles between 0° and 2° are determined. The observed reaction-angle dependence of each state is reproduced by theoretical calculations. However, the quantitative comparison with our high-precision data reveals a significant discrepancy between the measured and calculated formation cross sections of the pionic 1s state.

A Web-based searchable system to confirm magnetic resonance compatibility of implantable medical devices in Japan: a preliminary study

Confirmation of the magnetic resonance (MR) compatibility of implanted medical devices (IMDs) is mandatory before conducting magnetic resonance imaging (MRI) examinations. In Japan, few such confirmation methods are in use, and they are time-consuming. This study aimed to develop a Web-based searchable MR safety information system to confirm IMD compatibility and to evaluate the usefulness of the system. First, MR safety information for intravascular stents and stent grafts sold in Japan was gathered by interviewing 20 manufacturers. These IMDs were categorized based on the descriptions available on medical package inserts as: "MR Safe," "MR Conditional," "MR Unsafe," "Unknown," and "No Medical Package Insert Available". An MR safety information database for implants was created based on previously proposed item lists. Finally, a Web-based searchable system was developed using this database. A questionnaire was given to health-care personnel in Japan to evaluate the usefulness of this system. Seventy-nine datasets were collected using information provided by 12 manufacturers and by investigating the medical packaging of the IMDs. Although the datasets must be updated by collecting data from other manufacturers, this system facilitates the easy and rapid acquisition of MR safety information for IMDs, thereby improving the safety of MRI examinations.

Repeated Intraportal Hepatocyte Transplantation in Analbuminemic Rats

The optimal site for implantation of isolated hepatocytes has not been established. We have developed a novel technique which allows repeated infusion of hepatocytes into the portal system via an indwelling catheter. Seven Nagase Analbuminemic rats (NAR) underwent single intra-portal infusion of 2 × 107 isolated normal albumin-producing rat hepatocytes. Another seven NAR rats underwent placement of indwelling catheters into the portal venous system via the gastroduodenal vein. Each of them received six batches of 5 × 106 normal albumin producing hepatocytes. Seven control NAR rats were infused repeatedly (intraportally) with saline only. Plasma albumin (ELISA) showed significant increase in experimental animals and was more pronounced (p < 0.05) in rats transplanted repeatedly than in those given a single dose of cells. Immunohistochemical staining of the liver sections confirmed the presence of transplanted albumin producing hepatocytes. Rats transplanted with a single large batch of isolated hepatocytes showed liver tissue damage, whereas those subjected to repeated cell infusions had normal liver histology. We have developed a novel intraportal transplantation method which allows successful engraftment of a large number of isolated hepatocytes.

Abstract OT1-02-01: Phase II neoadjuvant trial of nanoparticle almumin-bound paclitaxel and trastuzumab in patients with node-negative, Her-2 positive breast cancer (OMC-BC04)

Background: Neoadjuvant chemotherapy plus trastuzumab results in a 30% to 50% pathologic complete response (pCR) rate in HER-2 positive breast cancer and has been associated with improved therapeutic outcomes. Thus, the pCR rate can be useful in evaluating novel agents in this patient population. Albumin-bound (nab)-paclitaxel can reduce the toxicity of Paclitaxel while maintaining its efficacy. We reported that neoadjuvant therapy using Anthracycline based regimens (EC,AC,FEC) followed by a combination with nab-Paclitaxel and Trastuzumab was effective and safe by OMC-BC01 Study (Tanaka et al. Clin Breast Cancer 15:191-196). The pCR rate was 36% and 71% in the patients with estrogen receptor-positive and negative cancer, respectively. In addition, Tolaney et al. showed that adjuvant Paclitaxel and Trastuzumab for node-negative, HER-2 positive tumors measuring up to 3 cm in greatest dimension was associated with patients outcomes that were better than expected on the basis of historical data (Tolaney et al. N Engl J MED.2015 Jan 8:372(2):134-141). We conducted a clinical Phase II, multicenter, neoadjuvant trial of combination with nanoparticle albumin-bound Paclitaxel and Trastuzumab in patients with node-negative, Her-2 positive, estrogen receptor-negative breast cancer measuring up to 3 cm in greatest dimension.

Patients and Methods: nab-Paclitaxel and Trastuzumab as neoadjuvant therapy in patients with Her-2 positive, node-negative, estrogen receptor-negative breast cancer measuring up to 3 cm in greatest dimension. Patients are treated with neoadjuvant nab-Paclitaxel (260mg/m2) and Trastuzumab q21d x 4, and undergo surgery 4-6 weeks later from completing chemotherapy. The primary endpoint, pCR is defined as no evidence of invasive tumors in the final surgical sample both in the breast and axillary lymph nodes. Secondary endpoints include objective clinical response rate, histological response rate, disease-free interval, rate of breast conserving surgery, and the safety of the treatment.

Accrual: Presently, a total number of 1 patient have been included since start of the study. The expected end of accrual of 30 patients will be the last quarter 2018.

Citation Format: Iwamoto M, Tanaka S, Koda C, Kawaguchi K, Terasawa R, Sato N, Fujioka H, Kimura K, Uchiyama K. Phase II neoadjuvant trial of nanoparticle almumin-bound paclitaxel and trastuzumab in patients with node-negative, Her-2 positive breast cancer (OMC-BC04) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-02-01.

[Study of Preoperative 3D-CT Angiography of Uterine Artery in Patients with Uterine Cervical Cancer]

Depiction of the fine vessel can provide useful preoperative information for patients with uterine cervical cancer. Although angiography can visualize vessels in detail, it is invasive. MR-angiography is a minimally invasive method to depict vessels, but the resolution of images is insufficient for preoperative evaluation. In this study, we used less invasive three-dimensional CT angiography (3D-CTA) and reconstructed images of adaptive iterative dose resolution 3D (AIDR 3D) with display field of view (D-FOV), which are suitable for arteries with large and small diameters, and created the fusion images. Created images allowed the observation of vessel branch in wide area compared with angiography, and it was less invasive. We evaluated the utility of 3D-CTA for visualizing fine vessels branching from uterine artery as preoperative evaluation for radial hysterectomy. 3D-CTA was obtained in nine patients. Conventional reconstruction and magnification reconstruction (D-FOV: 320‒360 mm, 150 mm) was made using arterial phase. Normal volume rendering image (N-VR) was made from conventional reconstruction image, and hybrid volume rendering image (H-VR) was made from conventional and magnification reconstruction image. Visual evaluation of each VR image was performed by 5 trained radiologists. A Wilcoxon rank sum test was performed for each result. No statistical significance was found in the visualization of vessels with large diameter (p=0.81), but statistical significance was detected in the visualization of the uterine artery and its ascending/descending branches (p<0.05). H-VR could visualize fine vessels clearer than N-VR, and H-VR could depict a vascular map including fine vessels in a large field. Therefore, H-VR could provide useful information for surgical operation. Additional depiction of vein and ureter could clearly visualize the anatomical relationship of each structure, and new clinical finding of anatomical relationship between uterine artery and ureter was suggested. This new clinical finding was useful in radical hysterectomy in which crossing site of the uterine artery and ureter is dissected. This method is simple to create and useful for various clinical surgery.

Measurement of Excitation Spectra in the ^{12}C(p,d) Reaction near the η^{'} Emission Threshold

Excitation spectra of ^{11}C are measured in the ^{12}C(p,d) reaction near the η^{'} emission threshold. A proton beam extracted from the synchrotron SIS-18 at GSI with an incident energy of 2.5 GeV impinges on a carbon target. The momenta of deuterons emitted at 0° are precisely measured with the fragment separator (FRS) operated as a spectrometer. In contrast to theoretical predictions on the possible existence of deeply bound η^{'}-mesic states in carbon nuclei, no distinct structures are observed associated with the formation of bound states. The spectra are analyzed to set stringent constraints on the formation cross section and on the hitherto barely known η^{'}-nucleus interaction.

Establishment of a new cell line susceptible to Cyprinid herpesvirus 3 (CyHV-3) and possible latency of CyHV-3 by temperature shift in the cells

A new cell line named CCF-K104 predominantly consisting of fibroblastic cells showed optimal growth at temperatures from 25 °C to 30 °C. Serial morphological changes in the cells induced by Cyprinid herpesvirus 3 (CyHV-3) included cytoplasmic vacuolar formation, cell rounding and detachment. Mature virions were purified from CyHV-3-infected CCF-K104 cells by sucrose gradient ultracentrifugation and had a typical herpesvirus structure on electron microscopy. Infectious CyHV-3 was produced stably in CCF-K104 cells over 30 viral passages. Our findings showed that CCF-K104 is a useful cell line for isolation and productive replication of CyHV-3. A temperature shift from 25 °C to 15 °C or 35 °C did not allow serial morphological changes as observed at 25 °C for 14 days. Under the same conditions, real-time PCR showed that CyHV-3 was present with low viral DNA loads, suggesting that CyHV-3 may establish latent infection in CCF-K104 cells. Amplification of the left and right terminal repeat sequences of the CyHV-3 genome arranged in a head-to-tail manner was detected by nested PCR following an upshift in temperature from 25 °C to 35 °C. The PCR results suggested that the circular genome may represent a latent form of CyHV-3.

Combination simvastatin and metformin induces G1-phase cell cycle arrest and Ripk1- and Ripk3-dependent necrosis in C4-2B osseous metastatic castration-resistant prostate cancer cells

Castration-resistant prostate cancer (CRPC) cells acquire resistance to chemotherapy and apoptosis, in part, due to enhanced aerobic glycolysis and biomass production, known as the Warburg effect. We previously demonstrated that combination simvastatin (SIM) and metformin (MET) ameliorates critical Warburg effect-related metabolic aberrations of C4-2B cells, synergistically and significantly decreases CRPC cell viability and metastatic properties, with minimal effect on normal prostate epithelial cells, and inhibits primary prostate tumor growth, metastasis, and biochemical failure in an orthotopic model of metastatic CRPC, more effectively than docetaxel chemotherapy. Several modes of cell death activated by individual treatment of SIM or MET have been reported; however, the cell death process induced by combination SIM and MET treatment in metastatic CRPC cells remains unknown. This must be determined prior to advancing combination SIM and MET to clinical trial for metastatic CRPC. Treatment of C4-2B cells with combination 4 μM SIM and 2 mM MET (SIM+MET) led to significant G1-phase cell cycle arrest and decrease in the percentage of DNA-replicating cells in the S-phase by 24 h; arrest was sustained throughout the 96-h treatment. SIM+MET treatment led to enhanced autophagic flux in C4-2B cells by 72–96 h, ascertained by increased LC3B-II (further enhanced with lysosomal inhibitor chloroquine) and reduced Sequestosome-1 protein expression, significantly increased percentage of acidic vesicular organelle-positive cells, and increased autophagic structure accumulation assessed by transmission electron microscopy. Chloroquine, however, could not rescue CRPC cell viability, eliminating autophagic cell death; rather, autophagy was upregulated by C4-2B cells in attempt to withstand chemotherapy. Instead, SIM+MET treatment led to Ripk1- and Ripk3-dependent necrosis by 48–96 h, determined by propidium iodide-Annexin V flow cytometry, increase in Ripk1 and Ripk3 protein expression, necrosome formation, HMGB-1 extracellular release, and necrotic induction and viability rescue with necrostatin-1 and Ripk3-targeting siRNA. The necrosis-inducing capacity of SIM+MET may make these drugs a highly-effective treatment for apoptosis- and chemotherapy-resistant metastatic CRPC cells.

Multiple mitochondrial alterations in a case of myopathy

Mitochondrial alterations are the most common feature of human myopathies. A biopsy of quadriceps muscle from a 50-year-old woman exhibiting myopathic symptoms was examined by transmission electron microscopy. Biopsied fibers from quadriceps muscle displayed numerous subsarcolemmal mitochondria that contained crystalloids. Numbering 1-6 per organelle, these consisted of rows of punctuate densities measuring ∼0.34 nm; the parallel rows of these dots had a periodicity of ∼0.8 nm. The crystalloids were ensconced within cristae or in the outer compartment. Some mitochondria without crystalloids had circumferential cristae, leaving a membrane-free center that was filled with a farinaceous material. Other scattered fibrocyte defects included disruption of the contractile apparatus or its sporadic replacement by a finely punctuate material in some myofibers. Intramitochondrial crystalloids, although morphologically striking, do not impair organelle physiology to a significant degree, so the muscle weakness of the patient must originate elsewhere.

Abstract P2-19-06: Breast conserving surgery using volume replacement with oxidized regenerated cellulose: A cosmetic outcome analysis

Background: Breast conserving surgery (BCS) is a standard procedure for patients with early stage breast cancer. However, as the objective of BCS is to obtain both local control and a cosmetic outcome, it may lead to unsatisfying cosmetic results when the volume of resected tissue is large in order to secure an adequate oncological safety margin. Autologous flaps or artifact implants are commonly used when performing a replacement for a defect in the breast during BCS. Oxidized regenerated cellulose (ORC) is composed primarily of vegetable nitrocellulose and was originally developed as a styptic for surgery. We expected that the ORC would help induce granulation and fibrous tissue with reactive tissue fluid, and finally ORC would prevent adhesion between skin and pectoralis major muscle. In this study, we focused on short-term cosmetic outcomes after volume replacement with ORC after BCS.

Materials and Methods: Inclusion criteria of this study were the patients with early breast cancer indicated BCS that did not required breast reconstruction, or the patients who did not wish to undergo breast reconstruction with autologous flaps after BCS. We evaluated the cosmetic outcome of volume replacement with ORC after BCS, and also examined factors that may have influenced the results. The cosmetic outcomes of these patients were evaluated using scores based on the criteria of the Japan Breast Cancer Society.

Results: Ninety-four patients who underwent this procedure between January 2010 and August 2012 were reviewed. We evaluated cosmetic scores with regards to several clinical factors and the occurrence of complications after this procedure. The mean score of the cosmetic outcome of all patients was 9.5 points out of 12 points. Thirty-seven patients were categorized as “Excellent”, 34 were “Good”, 22 were “Fair”, and 1 was “Poor”. Patient age, body mass index, weight of the specimen, and ORC amount were not significantly different between patients with favorable cosmetic scores and those without.

Table 1. Univariate analyses of clinical factors according to the cosmetic outcome E/G* (n = 71)F/P# (n = 23)P valueAge52.5±12.656.0±10.30.23Body mass index22.0±3.723.3±4.10.15Specimen weight54.0±23.961.4±39.10.27ORC amount$3.2±1.23.2±1.20.95Values are expressed as the mean±SD. *Categorized as “Excellent” and “Good”. #Categorized as “Fair” and “Poor”. $ORC amount used for volume replacement.

However, the weight of the removed specimen was slightly higher in patients with an unfavorable cosmetic score. Although acute dermatitis and eczema was observed in 15% and 3% of patients, all of them were improved with conservative treatment. Cosmetic scores were significantly higher in patients without complications than in patients with complications.

Table 2. Cosmetic scores between patients with and without acute complications Cosmetic scores (mean±SD)P valusWithout9.8±2.00.003With8.0±2.4 

Conclusions: ORC replacement after BCS is a simple and reliable procedure. The selection of indication and prevention of complications are important for obtaining a better cosmetic outcome. To our knowledge, this is the first report to cosmetically evaluate a relatively large number of patients that have undergone ORC replacement after BCS.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-19-06.

Abstract P3-02-02: Use of contrast-enhanced computed tomography in clinical staging of asymptomatic breast cancer patients to detect asymptomatic distant metastases

Objective: The use of computed tomography (CT) with regards to the clinical staging of breast cancer (BC) patients has been on the increase in clinical practice. However, NCCN guidelines recommended the use of imaginng only in cases with locally advanced disease or signs of distant metastases (DM), and the benefits of routine CT have yet to be fully clarified. This study investigated the value of employing contrast-enhanced CT (CECT) to screen for DM in patients with asymptomatic BC.

Methods: The clinical records of 483 patients with asymptomatic BC who underwent CECT, also in order to detect BC spread, between April 2006 and January 2011 were reviewed. The CECT results were classified into normal, true-positive (metastases) or false-positive findings.

Results: Abnormal CECT findings, including true- and false-positive results, were detected in 65 patients (13.5%). Of these, 26 patients (5.4%) showed confirmed true metastatic disease, including 18 lung metastases, 11 liver metastases and 13 bone metastases. Upstaging to stage IV due to the results of the CECT was significantly associated with only larger tumos size (odds ratio, 33.4; 95% CI 12.1–92.5; P &lt; 0.0001) and lymph node status (odds ratio, 37.1; 95% CI 14.2–96.8; P &lt; 0.0001.)

Search for the Θ+ pentaquark via the π(-)p→K(-)X reaction at 1.92 GeV/c

The Θ(+) pentaquark baryon was searched for via the π(-)p→K(-)X reaction with a missing mass resolution of 1.4 MeV/c(2) (FWHM) at the Japan Proton Accelerator Research Complex (J-PARC). π(-) meson beams were incident on the liquid hydrogen target with a beam momentum of 1.92 GeV/c. No peak structure corresponding to the Θ(+) mass was observed. The upper limit of the production cross section averaged over the scattering angle of 2° to 15° in the laboratory frame is obtained to be 0.26 μb/sr in the mass region of 1.51-1.55 GeV/c(2). The upper limit of the Θ(+) decay width is obtained to be 0.72 and 3.1 MeV for J(Θ)(P)=1/2(+) and J(Θ)(P)=1/2(-), respectively, using the effective Lagrangian approach.

Evidence for heavy hyperhydrogen (Λ)(6)h

Evidence for the neutron-rich hypernucleus (Λ)(6)H is presented from the FINUDA experiment at DAΦNE, Frascati, studying (π+,π-) pairs in coincidence from the K(stop)(-) + (6)Li →(Λ)(6)H + π+ production reaction followed by (Λ)(6)H → (6)He + π- weak decay. The production rate of (Λ)(6) undergoing this two-body π- decay is determined to be (2.9 ± 2.0) × 10(-6)/K(stop)(-). Its binding energy, evaluated jointly from production and decay, is BΛ((Λ)(6)H) = (4.0 ± 1.1) MeV with respect to (5)H+Λ. A systematic difference of (0.98 ± 0.74) MeV between BΛ values derived separately from decay and from production is tentatively assigned to the (Λ)(6)H 0(g.s.)(+) → 1+ excitation.

Optical pacing of the embryonic heart

Light has been used to noninvasively alter the excitability of both neural and cardiac tissue 1-10. Recently, pulsed laser light has been shown to be capable of eliciting action potentials in peripheral nerves and in cultured cardiomyocytes 7-10. Here, we demonstrate for the first time optical pacing (OP) of an intact heart in vivo. Pulsed 1.875 μm infrared laser light was employed to lock the heart rate to the pulse frequency of the laser. A laser Doppler velocimetry (LDV) signal was used to verify the pacing. At low radiant exposures, embryonic quail hearts were reliably paced in vivo without detectable damage to the tissue, indicating that OP has great potential as a tool to study embryonic cardiac dynamics and development. In particular, OP can be utilized to control the heart rate, and thereby alter stresses and mechanically transduced signaling.

Possible involvement of microglia containing cyclooxygenase-1 in the accumulation of gonadotrophin-releasing hormone in the preoptic area in female rats

Prostaglandins (PGs), especially PGE(2), are involved in the hypothalamic control of gonadotrophin-releasing hormone (GnRH) release, acting at least in part on the terminal of GnRH axons in the median eminence. The present study aimed: (i) to clarify the role of PG(s) in regulating GnRH cell function at the level of the perikarya in the preoptic area; (ii) to determine the cyclooxygenase (COX) isozyme responsible for producing PG(s) that regulates GnRH perikarya; and (iii) to identify cell types that contain the responsible COX isozyme in female rats. A surge of luteinising hormone (LH) secretion was induced by oestrogen and progesterone in ovariectomised rats. Treatment of the rat before the LH surge with indomethacin, a nonselective COX inhibitor, or NS-398, a selective COX-2 inhibitor, did not interfere with the surge. However, treatment with indomethacin or flurbiprofen, a selective COX-1 inhibitor, significantly reduced the number of GnRH-immunoreactive cells in the preoptic area at the time of peak LH secretion during the surge. NS-398 did not affect the GnRH immunoreactivity. Double-labelled immunofluorescent histochemistry revealed COX-1 immunoreactivity in the vicinity of, but not within, GnRH containing neurones in the preoptic area. COX-2 immunoreactivity was not found in the same area. The COX-1 immunoreactivity was almost entirely localised in microglia in the preoptic area, but not in neurones or astrocytes. These results suggest that microglia in the preoptic area containing COX-1 are responsible for producing PG(s), which, in turn, facilitates the accumulation of GnRH during the gonadotrophin surge in female rats.

Clinical characteristics of acute pulmonary thromboembolism in Japan: results of a multicenter registry in the Japanese Society of Pulmonary Embolism Research

BACKGROUND

Although the incidence of acute pulmonary thromboembolism (APTE) has been increasing in Japan, patient characteristics, management strategies, and outcome have not yet been assessed in large series.

HYPOTHESIS

The present study was designed to investigate the current status of APTE in Japan.

METHODS

Of a total of 533 registry patients with pulmonary thromboembolism, 309 with APTE were analyzed with respect to clinical symptoms and signs, predisposing factors, diagnostic procedures, estimation of deep venous thrombosis, treatment, and clinical course.

RESULTS

Main risk factors were recent major surgery, cancer, prolonged immobilization, and obesity; only a few patients had coagulopathy and 36% were in cardiogenic shock at presentation. The majority of registry patients underwent lung scans or pulmonary angiography; 30% were diagnosed only by lung scanning. Venous ultrasonography was used in only 34 patients, while 188 patients underwent at least one diagnostic procedure for deep venous thrombosis. Thrombolysis was more frequently performed in patients with cardiogenic shock, and only a few patients received thromboembolectomy. In-hospital mortality rate was 14%. In patients with cardiogenic shock, the mortality rate was reduced by thrombolysis. The predictors of in-hospital mortality were male gender, cardiogenic shock, cancer, and prolonged immobilization.

CONCLUSIONS

The patients in this registry had almost the same findings as those in Western patients, except for some points that had the possibility of demonstrating a difference between Westerners and Japanese in the development of APTE. These results can prove especially helpful in planning prospective, randomized trials that will clarify the impact of widely used treatment modalities on the outcome of patients with APTE.

EFFECT OF LIFESTYLE FACTORS ONINFERTILITY IN MEN

Environmental factors, changes in lifestyle and occupational exposures are responsible for declining human semen quality. We investigated the effects of history of surgery and lifestyle choices on infertility of 271 infertile men and 251 healthy volunteers. The frequency of varicocelectomy was significantly higher in infertile men (2.9%) than in controls (0.4%; P < 0.05). Alcohol use was significantly more common in infertile men (92%) than in controls (80%; P < 0.01). Satisfaction with sexual life was greater in controls (85%) than in infertile men (77%; P < 0.05). Other factors had no effect.

ERECTILE FUNCTION AFTER BRACHYTHERAPY WITH EXTERNAL BEAM RADIATION FOR PROSTATE CANCER

The effect of therapeutic modalities on sexual potency is an important consideration for patients choosing a treatment for prostate cancer. We assessed erectile function after iridium-192 (1r-192) high-dose rate (HDR) brachytherapy with external beam radiation therapy (EBRT), and examined the efficacy of sildenafil after this treatment. Forty-two prostate cancer patients (T1c to T3bN0M0) were treated with 22Gy HDR brachytherapy with 36.8Gy EBRT without neoadjuvant hormone therapy. Erectile function was assessed using a 5-item version of the International Index of Erectile Function questionnaire (IIEF-5), pre, 3 and 12 months after treatment, Potency was defined as an IIEF-5 score > or = 11. Ten patients with potency before HDR brachytherapy with EBRT with or without neoadjuvant hormone therapy requested Sildenafil 3 months after treatment. The mean IIEF-5 score of all patients was 10.5 +/- 8.5, 4.5 +/- 5.3 (p < 0.001), and 3.8 +/- 4.7 (p < 0.001), pre, 3 and 12 months after treatment, respectively. Seventeen (40.4%) patients were potent before treatment. The mean IIEF-5 score of those patients was 15.8 +/- 3.2, 9.6 +/- 5.1 (p = 0.04), and 11.3 +/- 6.1 (p = 0.06), pre, 3 and 12 months after treatment, respectively. Ten of 17 (58.8%) patients maintained their potency 12 months after treatment. In 10 patients with potency before treatment who were treated with sildenafil, the mean IIEF-5 score increased from 6.2 +/- 3.5 at 3 months to 13.6 +/- 5.1 (p < 0.001) at 12 months after treatment. Eight of 10 (80%) patients treated with sildenafil had recovered 12 months after treatment. HDR brachytherapy with EBRT can be performed with favorable results for maintaining potency.

Liquid plug propagation in flexible microchannels: A small airway model

In the present study, we investigate the effect of wall flexibility on the plug propagation and the resulting wall stresses in small airway models with experimental measurements and numerical simulations. Experimentally, a flexible microchannel was fabricated to mimic the flexible small airways using soft lithography. Liquid plugs were generated and propagated through the microchannels. The local wall deformation is observed instantaneously during plug propagation with the maximum increasing with plug speed. The pressure drop across the plug is measured and observed to increase with plug speed, and is slightly smaller in a flexible channel compared to that in a rigid channel. A computational model is then presented to model the steady plug propagation through a flexible channel corresponding to the middle plane in the experimental device. The results show qualitative agreements with experiments on wall shapes and pressure drops and the discrepancies bring up interesting questions on current field of modeling. The flexible wall deforms inward near the plug core region, the deformation and pressure drop across the plug increase with the plug speed. The wall deformation and resulting stresses vary with different longitudinal tensions, i.e., for large wall longitudinal tension, the wall deforms slightly, which causes decreased fluid stress and stress gradients on the flexible wall comparing to that on rigid walls; however, the wall stress gradients are found to be much larger on highly deformable walls with small longitudinal tensions. Therefore, in diseases such as emphysema, with more deformable airways, there is a high possibility of induced injuries on lining cells along the airways because of larger wall stresses and stress gradients.

Glucagon-like peptide-1 (GLP-1) protects against methylglyoxal-induced PC12 cell apoptosis through the PI3K/Akt/mTOR/GCLc/redox signaling pathway

Patients with long-standing diabetes commonly develop diabetic encephalopathy, which is characterized by cognitive impairment and dementia. Oxidative stress-induced neuronal cell apoptosis is a contributing factor. Glucagon-like peptide (GLP)-1 has recently become an attractive treatment modality for patients with diabetes. It also readily enters the brain, prevents neuronal cell apoptosis, and improves the cognitive impairment characteristic of Alzheimer's disease. Therefore, we investigated whether GLP-1 could protect against oxidative stress-induced neuronal cell apoptosis in pheochromocytoma (PC12) cells. PC12 cells were exposed to 1 mM methylglyoxal (MG) or MG plus 3.30 microg/ml GLP-1. Cell apoptosis, expression and phosphorylation of phosphatidylinositol-3 kinase/Akt/mammalian target of rapamycin/gamma-glutamylcysteine ligase catalytic subunit (GCLc), and redox balance were then determined. The data showed that MG induced PC12 apoptosis in accordance with the redox (glutathione (GSH) and GSH/glutathione disulfide [GSSG]) imbalance. GLP-1 protected against this MG-induced apoptosis, which corresponded to the phosphorylation of PI3K, Akt, and mTOR, as well as the upregulation of GCLc and the restoration of the redox imbalance. Inhibitors of PI3K (LY294002), Akt (Akt-I), and mTOR (rapamycin) reduced the GLP-1-induced GCLc upregulation and its protection against MG-induced PC12 apoptosis. The GLP-1-induced redox restoration was also attenuated by rapamycin. In conclusion, the neuroprotective effect of GLP-1 is due to an enhancement of PI3K/Akt/mTOR/GCLc/redox signaling.

Increased testicular 8-hydroxy-2'-deoxyguanosine in patients with varicocele

OBJECTIVES

To assess immunohistochemically 8-hydroxy-2'-deoxyguanosine (8-OHdG, a sensitive biological marker of oxidative damage and stress) in testicular tissue from patients with varicocele, to determine whether 8-OHdG is related to spermatogenesis, as oxidative stress in testicular DNA is associated with poor semen quality and reduced fertility.

PATIENTS, SUBJECTS AND METHODS

Testicular tissue samples were collected from the testes of 36 patients with varicocele and five normal volunteers. The mean (sd) age of the patients was 35.3 (5.4) years. The prevalence of immunostained germ cells among all the germ cells in >20 seminiferous tubules was calculated.

RESULTS

The mean (sd) sperm concentration and Johnsen's score in the varicocele group was lower than in the normal group, at 27.6 (11.8) vs 80.4 (21.7) million/mL (P < 0.001) and 7.6 (1.1) vs 9.0 (0.7), respectively (P < 0.05). In all patients, 8-OHdG was mainly expressed in the spermatogonia and spermatocytes in the seminiferous tubule. Immunostained germ cells correlated negatively with sperm concentration (r = -0.48, P = 0.01) and Johnsen's score (r = -0.46, P = 0.02), but not with follicle-stimulating hormone, luteinizing hormone or testosterone level. Immunostained germ cells were significantly more prevalent in the varicocele group, at 53.6 (5.7)%, than that in the normal group, at 14.3 (2.3)% (P < 0.001). The prevalence of immunostained germ cells and clinical grades were positively related; the ratio recorded for varicocele grades I, II and III was 38.0 (10.0)%, 41.0 (9.1)%, and 57.0 (9.3)%, respectively (grade I vs grade III, P < 0.05).

CONCLUSIONS

Increased 8-OHdG expression in the testis was associated with deficient spermatogenesis in infertile men with varicocele.

Surgery for clavicular and humeral fractures in an osteopetrotic patient: a case report

Osteopetrosis is a rare disease characterised by generalised sclerosis of the bone. Surgical treatment for fractures in osteopetrotic bones is difficult due to their hardness. We report successful surgical treatment of humeral and clavicular fractures in a 30-year-old osteopetrotic patient with severe multiple trauma. Two years after surgery, the patient had a full range of movement at the shoulder and elbow, with good bone union and alignment.