Persistent magnetic coherence in magnets.

When excited, the magnetization in a magnet precesses around the field in an anticlockwise manner on a timescale governed by viscous magnetization damping, after which any information carried by the initial actuation seems to be lost. This damping appears to be a fundamental bottleneck for the use of magnets in information processing. However, here we demonstrate the recall of the magnetization-precession phase after times that exceed the damping timescale by two orders of magnitude using dedicated two-colour microwave pump-probe experiments for a Y3Fe5O12 microstructured film. Time-resolved magnetization state tomography confirms the persistent magnetic coherence by revealing a double-exponential decay of magnetization correlation. We attribute persistent magnetic coherence to a feedback effect, that is, coherent coupling of the uniform precession with long-lived excitations at the minima of the spin-wave dispersion relation. Our finding liberates magnetic systems from the strong damping in nanostructures that has limited their use in coherent information storage and processing.

Theranostic SPECT reconstruction for improved resolution: application to radionuclide therapy dosimetry.

BACKGROUND: SPECT-derived dose estimates in tissues of diameter less than 3× system resolution are subject to significant losses due to the limited spatial resolution of the gamma camera. Incorporating resolution modelling (RM) into the SPECT reconstruction has been proposed as a possible solution; however, the images produced are prone to noise amplification and Gibbs artefacts. We propose a novel approach to SPECT reconstruction in a theranostic setting, which we term SPECTRE (single photon emission computed theranostic reconstruction); using a diagnostic PET image, with its superior resolution, to guide the SPECT reconstruction of the therapeutic equivalent. This report demonstrates a proof in principle of this approach. METHODS: We have employed the hybrid kernelised expectation maximisation (HKEM) algorithm implemented in STIR, with the aim of producing SPECT images with PET-equivalent resolution. We demonstrate its application in both a dual 68Ga/177Lu IEC phantom study and a clinical example using 64Cu/67Cu. RESULTS: SPECTRE is shown to produce images comparable in accuracy and recovery to PET with minimal introduction of artefacts and amplification of noise. CONCLUSION: The SPECTRE approach to image reconstruction shows improved quantitative accuracy with a reduction in noise amplification. SPECTRE shows great promise as a method of improving SPECT radioactivity concentrations, directly leading to more accurate dosimetry estimates in small structures and target lesions. Further investigation and optimisation of the algorithm parameters is needed before this reconstruction method can be utilised in a clinical setting.

Room temperature and low-field resonant enhancement of spin Seebeck effect in partially compensated magnets.

Resonant enhancement of spin Seebeck effect (SSE) due to phonons was recently discovered in Y[Formula: see text]Fe[Formula: see text]O[Formula: see text] (YIG). This effect is explained by hybridization between the magnon and phonon dispersions. However, this effect was observed at low temperatures and high magnetic fields, limiting the scope for applications. Here we report observation of phonon-resonant enhancement of SSE at room temperature and low magnetic field. We observe in Lu[Formula: see text]BiFe[Formula: see text]GaO[Formula: see text] an enhancement 700% greater than that in a YIG film and at very low magnetic fields around 10[Formula: see text] T, almost one order of magnitude lower than that of YIG. The result can be explained by the change in the magnon dispersion induced by magnetic compensation due to the presence of non-magnetic ion substitutions. Our study provides a way to tune the magnon response in a crystal by chemical doping, with potential applications for spintronic devices.

Fast Heating of Imploded Core with Counterbeam Configuration.

A tailored-pulse-imploded core with a diameter of 70 µm is flashed by counterirradiating 110 fs, 7 TW laser pulses. Photon emission (>40 eV) from the core exceeds the emission from the imploded core by 6 times, even though the heating pulse energies are only one seventh of the implosion energy. The coupling efficiency from the heating laser to the core using counterirradiation is 14% from the enhancement of photon emission. Neutrons are also produced by counterpropagating fast deuterons accelerated by the photon pressure of the heating pulses. A collisional two-dimensional particle-in-cell simulation reveals that the collisionless two counterpropagating fast-electron currents induce mega-Gauss magnetic filaments in the center of the core due to the Weibel instability. The counterpropagating fast-electron currents are absolutely unstable and independent of the core density and resistivity. Fast electrons with energy below a few MeV are trapped by these filaments in the core region, inducing an additional coupling. This might lead to the observed bright photon emissions.

Direct heating of a laser-imploded core by ultraintense laser-driven ions.

A novel direct core heating fusion process is introduced, in which a preimploded core is predominantly heated by energetic ions driven by LFEX, an extremely energetic ultrashort pulse laser. Consequently, we have observed the D(d,n)^{3}He-reacted neutrons (DD beam-fusion neutrons) with the yield of 5×10^{8} n/4π sr. Examination of the beam-fusion neutrons verified that the ions directly collide with the core plasma. While the hot electrons heat the whole core volume, the energetic ions deposit their energies locally in the core, forming hot spots for fuel ignition. As evidenced in the spectrum, the process simultaneously excited thermal neutrons with the yield of 6×10^{7} n/4π sr, raising the local core temperature from 0.8 to 1.8 keV. A one-dimensional hydrocode STAR 1D explains the shell implosion dynamics including the beam fusion and thermal fusion initiated by fast deuterons and carbon ions. A two-dimensional collisional particle-in-cell code predicts the core heating due to resistive processes driven by hot electrons, and also the generation of fast ions, which could be an additional heating source when they reach the core. Since the core density is limited to 2 g/cm^{3} in the current experiment, neither hot electrons nor fast ions can efficiently deposit their energy and the neutron yield remains low. In future work, we will achieve the higher core density (>10 g/cm^{3}); then hot electrons could contribute more to the core heating via drag heating. Together with hot electrons, the ion contribution to fast ignition is indispensable for realizing high-gain fusion. By virtue of its core heating and ignition, the proposed scheme can potentially achieve high gain fusion.

Fusion using fast heating of a compactly imploded CD core.

A compact fast core heating experiment is described. A 4-J 0.4-ns output of a laser-diode-pumped high-repetition laser HAMA is divided into four beams, two of which counterilluminate double-deuterated polystyrene foils separated by 100 µm for implosion. The remaining two beams, compressed to 110 fs for fast heating, illuminate the same paths. Hot electrons produced by the heating pulses heat the imploded core, emitting x-ray radiations >20 eV and yielding some 10(3) thermal neutrons.

Real time reverse transcriptase polymerase chain reaction of urinary cytokeratin 20 detects transitional cell carcinoma cells.

PURPOSE: We evaluate the diagnostic use of cytokeratin 20 messenger (m) RNA quantitation in urine as a marker of urothelial transitional cell carcinoma using the real time reverse transcriptase polymerase chain reaction (RT-PCR). MATERIALS AND METHODS: Spontaneously voided urine was obtained from 47 patients with urothelial transitional cell carcinoma (carcinoma group), 19 other urological diseases (noncarcinoma group) and 27 healthy volunteers (control group). Quantification of cytokeratin 20 was performed with mRNA extracted from urine samples with primers and hybridization probes specific for cytokeratin 20 on a LightCycler instrument (Roche Diagnostics Corp., Indianapolis, Indiana). RESULTS: This method allowed reproducible quantitation of 10 to 106 cytokeratin 20 expressing colon carcinoma cells per 107 peripheral blood leukocytes, comparable to the sensitivity of conventional RT-PCR with a wide linear measuring range. Cytokeratin 20 mRNA values in the carcinoma group (mean 35,850) were significantly higher than noncarcinoma (171) and control groups (4.55, p <0.0001 and <0.0001, respectively). Urinary cytokeratin 20 mRNA values significantly correlated with tumor grade, urinary cytological class, immunostaining pattern and depth of tumor invasion. Sensitivity and specificity of real time RT-PCR with a cutoff value of 15 were 81% and 83%, whereas those of conventional cytology were 28% and 100%, respectively. CONCLUSIONS: These results indicate that real time cytokeratin 20 RT-PCR is a sensitive, quantitative, rapid and specific method to detect free cancer cells in the urine, with good potential for monitoring recurrence of urothelial transitional cell carcinoma.

Aminopeptidase N regulated by zinc in human prostate participates in tumor cell invasion.

Aminopeptidase N (AP-N) degrades collagen type IV and is proposed to play a role in tumor invasion. However, the precise functions of AP-N in tumor cells and the relationship of AP-N to prostate cancer remains unclear. In our study, we examined a possible role for zinc in the regulation of AP-N enzymatic activity in relation to tumor cell invasion in human prostate. AP-N purified from human prostate was irreversibly inhibited by low concentrations of zinc (Ki = 11.2 microM) and bestatin. AP-N, which has zinc in the active center, was also inhibited by the chelating agents, EDTA, o-phenanthroline and EGTA. EDTA was shown to remove zinc from the enzyme. When the effects of zinc and bestatin on invasion of PC-3 cells were investigated in vitro using a Transwell cell-culture chamber, zinc and bestatin effectively suppressed cell invasion into Matrigel at the concentration range of 50-100 microM. These results strongly suggest that the suppression of PC-3 cell invasion by zinc is based on the inhibition of AP-N activity by zinc. We also evaluated the expression of AP-N to investigate the relationship with the progression of prostate disease in human cancerous prostate. AP-N was found to be located at the cytoplasmic membranes of prostate gland epithelial cells and to be expressed more in prostate cancer, while the expression of prostate-specific antigen (PSA), which is a useful marker for prostate cancer, was shown in normal and cancer tissues, suggesting that AP-N is potentially a good histological marker of prostate cancer. Thus, highly expressed AP-N in human cancerous prostate probably plays an important role in the invasion and metastasis of prostate cancer cells.

An anterior urethral stitch improves urinary incontinence following radical prostatectomy.

OBJECTIVE: To determine the effects of an anterior urethral stitch, referred to as an endopelvic anterior urethral stitch (EAUS), in reducing recovery time for post-prostatectomy urinary incontinence. METHODS: The urinary continence recovery time for 24 patients, who received a retropubic radical prostatectomy with the EAUS procedure, was compared to that of a historical control series of 22 patients without EAUS. The EAUS is a simple 2-0 polyglactin stitch placed between the bunched dorsal vein complex and the anterior urethra. This procedure was performed at the time of urethro-vesical anastomosis. Continence recovery time was defined as the day after removal of the urethral catheter when the patient no longer required pads for incontinence. RESULTS: A significantly shorter time for continence recovery (median 8.5 days) was obtained in EAUS patients compared with that of the control series (median 72 days) (P < 0.0001). Early recovery of continence was observed in 12/24 patients (50%) within 1 week and 18/24 patients (75%) within 1 month in EAUS patients. No adverse effects or complications were observed in the EAUS patients. CONCLUSION: A surgical procedure, the EAUS, has been developed that reduces urinary incontinence in patients who have undergone a radical prostatectomy. This procedure is simple and quick and improves recovery of continence without any side-effects.

[Kinetics of peripheral blood CD34-positive cells and the optimum timing for harvesting peripheral blood stem cells during BEP chemotherapy in patients with testicular germ cell tumor].

PURPOSE: Recently, high-dose chemotherapy with peripheral blood stem cell (PBSC) rescue has been developed for poor risk testicular germ cell cancer. In this study, we investigated the optimum timing for harvesting PBSCs with the use of bleomycin + etoposide + cisplatin (BEP) chemotherapy, which is a well known first-line regimen for the testicular cancer. MATERIAL AND METHOD: Peripheral blood CD34-positive cell ratios were measured during a total of 10 courses of BEP chemotherapy in 6 patients with metastatic germ cell cancer between 1996 and 1998. We performed 4 apheresis in 3 patients during this period. Recombinant human granulocyte-colony stimulating factor (rhG-CSF) was administrated from the day on which the neutrophil count decreased less than 1,000/microliter. RESULTS: The peripheral blood CD34-positive cell ratios became maximum (3.0-24.6%; average 10.0%) on the day 18 to 21 (median day 19) of BEP chemotherapy with rhG-CSF administration. The maximum ratios of peripheral blood CD34 positive cells were achieved when the number of leukocyte were 6,880-23,600/microliter and exceeded 6,000/microliter after the 18th day of BEP chemotherapy. The average number of collected CD34 positive cells was 9.5 x 10(6)/kg at a single apheresis, and 12.6 x 10(6)/kg per patient. CONCLUSION: Efficient hematopoietic progenitor cells were mobilized by BEP chemotherapy with rhG-CSF administration of first-line setting. Our results suggest that the optimum timing of PBSCs harvest is the day when the numbers of leukocyte exceed 6,000/microliter after the 18th day of BEP chemotherapy and the following day.

Developmental changes in distribution of death-associated protein kinase mRNAs.

Death-associated protein kinase (DAP-kinase) is Ca(2+)/calmodulin-dependent serine/threonine kinase that contains ankyrin repeats and the death domain. It has been isolated as a positive mediator of interferon-gamma-induced apoptotic cell death of HeLa cells. In order to reveal the physiological role of DAP-kinase, the tissue distribution and developmental changes in mRNA expression of DAP-kinase were investigated by Northern blot and in situ hybridization analyses. DAP-kinase mRNA was predominantly expressed in brain and lung. In brain, DAP-kinase mRNA had already appeared at embryonic day 13 (E13) and was, thereafter, detected throughout the entire embryonic period. High levels of expression were detected in proliferative and postmitotic regions within cerebral cortex, hippocampus, and cerebellar Purkinje cells. These findings suggest that DAP-kinase may play an important role in neurogenesis where a physiological type of cell death takes place. The overall expression of DAP-kinase mRNA in the brain gradually declined at postnatal stages, and the expression became restricted to hippocampus, in which different expression patterns were observed among rostral, central, and caudal coronal sections, suggesting that DAP-kinase may be implicated in some neuronal functions. Furthermore, it was found that the expression of DAP-kinase mRNA was increased prior to a certain cell death induced by transient forebrain ischemia, indicating a possible relationship between DAP-kinase and neuronal cell death.

[Detection of circulating cancer cells by nested reverse transcription-polymerase chain reaction of cytokeratin-19 in patients with renal cell carcinoma].

Detection of circulating cancer cells in peripheral blood may improve cancer staging and monitoring. This study was undertaken to investigate the clinical implications of detection of circulating cancer cells in renal cancer patients. Cytokeratin-19 (CK19) mRNA was amplified by nested reverse transcription-polymerase chain reaction (RT-PCR) in the peripheral blood of 33 healthy volunteers and 19 patients with renal cell carcinoma. The detection limit of the method was 10 cancer cells in 10(7) peripheral blood mononuclear cells. The positive detection rate was 47% for renal cancer patients and 9% for healthy volunteers. The number of patients expressing CK19 mRNA in each clinical stage was 0 out of 3 patients in stage 1; 2 out of 8 (25%) in stage 2; 3 out of 4 (75%) in stage 3; 4 out 4 (100%) in stage 4. A significant correlation was seen between CK19 mRNA expression and clinical stage (p = 0.0023). This method may be useful for early detection of micrometastasis, and facilitate the design of better therapeutic strategies for the treatment of renal cancer patients.

Stereologically estimated mean nuclear volume of prostatic cancer is a reliable prognostic parameter.

Although different histological grading systems of prostatic cancer refer to well-described characteristics, results are hard to reproduce. The aim of this study was to obtain morphometric data that would enable objective and reproducible grading of prostatic cancers by stereological estimation of mean nuclear volume (MNV). The clinical records and tissue specimens from 100 patients who were newly diagnosed as having prostatic cancer from 1973 to 1990 and who were followed up for 5 years or longer were retrospectively examined. We analysed the relationship between MNV and clinical stage, Gleason score and histological grading according to the World Health Organization (WHO) classification. To evaluate prognostic predictors, a multivariate analysis of factors associated with cause-specific survival was performed. We found a good correlation between the MNV and clinical stage and between the MNV and histological grading. There was no correlation between MNVs and Gleason scores. Multivariate analysis revealed that the MNV was the only predictor of survival time (coefficient 0.005; P < 0.0001; hazard ratio 1.005). We consider that the MNV is an excellent predictor of the prognosis in patients with prostatic cancer. Moreover, stereological estimation of MNV is a simple, quick, inexpensive and reliable morphometric procedure that enables the quantitative analysis of the histological and biological character of prostatic cancer.

All-optical modulation with anomalous photovoltaic film on a Ti:LiNbO(3) waveguide modulator.

An anomalous photovoltaic film formed by simultaneous oblique sputter deposition of CdTe and CdS from different directions was integrated onto LiNbO(3) and combined with a Mach-Zehnder-type interferometric waveguide modulator. Irradiation by 830-nm laser light with low intensity near 1 mW of the photovoltaic film induced anomalous photovoltages of ~5 V, which is as high as the half-wave voltage. This photovoltage was used to control the signal light in the waveguide. Modulation by external light was demonstrated with a response time of 0.1 s. Because of the presence of CdS with a photoconductive effect, the response time was much faster than that of conventional anomalous photovoltaic films formed by oblique deposition of CdTe.

HNF-6 is expressed in endoderm derivatives and nervous system of the mouse embryo and participates to the cross-regulatory network of liver-enriched transcription factors.

Hepatocyte nuclear factor-6 (HNF-6) is a liver-enriched transcription factor that contains a single cut domain and a novel type of homeodomain. Here we have studied the developmental expression pattern of HNF-6 in the mouse. In situ hybridization experiments showed that HNF-6 mRNA is detected in the liver at embryonic day (E) 9, at the onset of liver differentiation. HNF-6 mRNA disappeared transiently from the liver between E12.5 and E15. In transfection experiments HNF-6 stimulated the expression of HNF-4 and of HNF-3 beta, two transcription factors known to be involved in liver development and differentiation. HNF-6 was detected in the pancreas from E10.5 onward, where it was restricted to the exocrine cells. HNF-6 was also detected in the developing nervous system. Both the brain and the spinal cord started to express HNF-6 at E9-9.5 in postmitotic neuroblasts. Later on, HNF-6 was restricted to brain nuclei, to the retina, to the ventral horn of the spinal cord, and to dorsal root ganglia. Our observations that HNF-6 contributes to the control of the expression of transcription factors and is expressed at early stages of liver, pancreas, and neuronal differentiation suggest that HNF-6 regulates several developmental programs.

[Effect of pamidronate and interferon-alpha on bone and lung metastases and hypercalcemia in a patient with renal cell carcinoma].

Pamidronate is a second generation bisphosphonate used for treating tumor-induced hypercalcemia and for preventing the development of new bone metastasis. A 47-year-old man with renal cell carcinoma was admitted in our institution because of hypercalcemia with multiple metastasis in bone, lung and lymph nodes. After embolization of the right renal artery, the patient was treated with pamidronate and interferon-alpha. Intravenous pamidronate significantly reduced bone pain and normalized the serum calcium level. The pulmonary metastasis responded to interferon therapy after 2 months of therapy. Radical nephrectomy was then carried out. Paraaortic lymph nodes were found to be necrosed completely. Ossification of osteolytic lesions was observed after two months of therapy and metastatic lesions in the lung showed complete remission (CR) after six months of therapy.

[Influence of extracorporeal shock wave lithotripsy (ESWL) on renal function assessed by 99mTc-DMSA scintigraphy: comparative analysis between ESWL and percutaneous nephroureterolithotripsy (PNL)].

99mTc-DMSA renal scintigraphy was utilized to investigate the influence of ESWL on renal function in comparison with that of PNL. In the beginning, the reproducibility of renal uptake rate by the scintigraphy was examined in eleven healthy volunteers under both non-diuretic and diuretic states. The renal uptake rate was shown to be sufficiently reproducible in the same person in the two different trials. However, the differences and the standard deviations were shown to be a few percentages, which were not statistically significant. Changes in the repeated renal uptake rate seem to indicate not only changes of renal function with the treatment but also some technical errors. Herein, to investigate changes in renal function of the therapeutic side, the uptake ratio rate (rate of uptake rate in the therapeutic side/uptake rate in the contral lateral side) was utilized instead of uptake rate. Renal scintigraphy was carried out in 48 patients with unilateral renal stones before and after ESWL or PNL monotherapy or the combined ESWL and PNL therapies. Within one week of treatment, the uptake ratio rate significantly decreased in patients with PNL or the combined ESWL and PNL, although DMSA uptake rate in the therapeutic side did not significantly changes. Neither renal uptake rate nor uptake ratio rate significantly changed after ESWL treatment. There was no significant difference in changes of uptake ratio rate between Siemens Lithostars Plus and the improved Dornier HM-3 lithotriptors. This study indicated that ESWL monotherapy did not affect the uptake ratio rate, although PNL monotherapy and the combined ESWL and PNL therapies may affect the uptake ratio rate to some extent.

[Mass screening for prostate cancer at a local town--five-year results and screening system].

The results of a mass screening examination for prostate cancer conducted from 1989 to 1993 at a local town, Kawagoe-cho, in Mie Prefecture were evaluated. Among the 216 examinees, 4 were found to have prostate cancer. The most accurate examination was the prostate specific antigen (PSA), which was followed by digital examination and transrectal ultrasound. The applicants for the prostate cancer screening accounted for only 8% of the Kawagoe-cho male residents over 40 years old. An educational campaign of prostate disease in the area must be started to increase the number of applicants. We concluded that the most effective modality for the screening program was a combination of PSA and digital examination in the field study, and transrectal ultrasound accompanied by systemic biopsy results in the second tool for screening.