Electro-optic probe measurements of electric fields in plasmas.

The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas.

Patient-controlled bolus femoral nerve block after knee arthroplasty: quadriceps recovery, analgesia, local anesthetic consumption.

BACKGROUND: Continuous femoral nerve block (cFNB) induces quadriceps muscle weakness, but patient-controlled femoral nerve block (PCFNB) can provide analgesia with lower consumption of local anesthetics compared to cFNB. We hypothesized that cFNB followed by PCFNB leads to accelerated recovery of quadriceps weakness after total knee arthroplasty compared to cFNB alone. Secondary outcomes were local anesthetic consumption, pain, and mobilization. METHODS: Fifty-six subjects received post-operative cFNB for 24 h and then randomized to receive either cFNB (basal infusion of 6 ml/h using a dummy bolus button; n = 27) or PCFNB (bolus infusion of 3 ml with a lockout time of 30 min and no basal infusion; n = 29) using 0.08% levobupivacaine for the subsequent 24 h in a double-blind manner (registration: UMIN000010105). Quadriceps strength was assessed using a hand-held dynamometer. The percentage change from baseline was compared between groups. RESULTS: Quadriceps strength at 48 h was 47.3 ± 18.3% in the cFNB group and 49.7 ± 15.7% in the PCFNB group (95% confidence interval -7.0-11.9%, P = 0.61). Local anesthetic consumption during the post-operative period was significantly lower in the PCFNB group compared to the cFNB group (102 ± 10.8 ml vs.146 ± 4.6 ml; P < 0.001). No significant differences were found in any of the other outcomes, including pain scores at rest and during knee rehabilitation. CONCLUSION: Continuous femoral nerve block followed by PCFNB does not improve quadriceps strength recovery time compared to cFNB alone after total knee arthroplasty, but similar analgesic effects were demonstrated with reduced levobupivacaine consumption.

Does surgery improve live birth rates in patients with recurrent miscarriage caused by uterine anomalies?

We found that congenital uterine anomalies have a negative impact on reproductive outcome in recurrent-miscarriage couples, being associated with further miscarriage with a normal embryonic karyotype. There has been no study comparing live birth rates between patients with and without surgery. We conducted a prospective study to prove that surgery for a bicornuate or septate uterus might improve the live birth rate. A total of 170 patients with congenital uterine anomalies suffering two or more miscarriages were examined. The live birth rate after ascertainment of anomalies, cumulative live birth rate and infertility rate, were compared between patients with and without surgery. In patients with a septate uterus, the live birth rate (81.3%) at the first pregnancy after ascertainment of anomalies with surgery tended to be higher than that (61.5%) in those without surgery. The infertility rates were similar in both groups, while the cumulative live birth rate (76.1%) tended to be higher than without surgery (60.0%). Surgery showed no benefit in patients with a bicornuate uterus for having a baby, but tended to decrease the preterm birth rate and the low birth weight. The possibility that surgery has benefits for having a baby in patients with a septate uterus suffering recurrent miscarriage could not be excluded.

Accumulation of advanced glycation end products in women with preeclampsia: possible involvement of placental oxidative and nitrative stress.

Advanced glycation end products (AGEs) are known to cause oxidative damage in various cells by binding with its receptor, RAGE. We measured the serum level of AGEs and examined the AGEs, RAGE, and the other biomarkers of oxidative stress in the placentas from preeclamptic women. Competitive ELISA was carried out to measure the AGEs in serum. Western blotting was performed to analyze AGEs and RAGE in the placenta. Immunohistochemical analyses were performed to examine the localization of AGEs, RAGE, and other biomarkers of oxidative stress in the placenta. The mean level of serum AGEs in preeclamptic women was significantly higher than that in healthy non-pregnant women or healthy pregnant women. Western blotting revealed that the level of AGEs or RAGE in preeclamptic placenta was significantly higher than that in normal placenta. Immunohistochemical analyses showed that levels of nitrotyrosine and nitroguanosine, which are formed by reactive nitrogen species, in preeclamptic placenta were higher than those in normal placenta. Accumulation of 4-hydroxy-2-nonenal and 8-hydroxy-2'-deoxyguanosine indicated enhanced oxidative modifications of lipids and DNA in preeclamptic placenta. The AGE-RAGE system, which is upregulated in preeclampsia, is likely to be involved in the oxidative stress of preeclampsia.

Advanced glycation end products induce secretion of chemokines and apoptosis in human first trimester trophoblasts.

BACKGROUND: We studied the effects of advanced glycation end products (AGEs), which are known to accumulate in patients with diabetes, autoimmune diseases, or that smoke, on human trophoblasts. METHODS: First trimester human chorionic villi of 6-10 week gestation were obtained. Expression and localization of the receptor for AGEs (RAGE) was examined by western blotting and immunohistochemistry. Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta, regulated upon activation, normal T-cell expressed and secreted (RANTES), and human chorionic gonadotropin (hCG) in culture medium were measured by ELISA. Trophoblastic apoptosis was evaluated by the Hoechst 33258 staining and the in situ nick end labeling technique. RESULTS: RAGE was localized in trophoblasts. AGEs significantly stimulated secretion of both MIP-1alpha and MIP-1beta from trophoblasts in a time- and dose-dependent manner. AGEs significantly induced apoptosis and reduced secretion of hCG. Increased secretions of MIP-1alpha and MIP-1beta by AGEs were significantly suppressed by inhibitors of nitric oxide synthase (NOS) or nafamostat mesilate, a synthetic serine protease inhibitor and a suppressor of transcription factor, NF-kappaB activation. These agents also suppressed the effects of AGEs on hCG secretion and trophoblastic apoptosis. CONCLUSIONS: These AGE-mediated changes in trophoblasts may lead to impairment of implantation and placentation. NOS inhibitors or nafamostat mesilate may modify these effects.

Multisegmented kinoform phase plate for spatial and temporal control of the focal-plane irradiance profile.

Kinoform phase plates (KPPs) are widely used in inertial confinement fusion to improve energy efficiency and to produce an optimum irradiance profile on the target plane. However KPPs are sensitive to beam aberrations and offer little flexibility in temporally tailoring the far-field pattern. To overcome these problems, we developed a multisegmented KPP and demonstrated temporal control of a focusing pattern and protection against phase distortions by numerical simulations.

Laguerre-Gaussian beam generated with a multilevel spiral phase plate for high intensity laser pulses.

We investigated an Laguerre-Gaussian (LG) beam that can carry an orbital angular momentum and has a doughnut-shaped intensity pattern. We developed a multilevel spiral phase plate (SPP) that generates an LG beam by applying the wave surface of a spiral structure directly to a Gaussian beam for application to microscopic laser material processing.We experimentally demonstrate, for the first time, that it is possible to generate an LG beam with the multilevel SPP that allows the use in high intensity laser pulses.

Extravasation on three-dimensional CT angiography in patients with acute subarachnoid hemorrhage and ruptured aneurysm.

Three-dimensional computed tomographic angiography (CTA) is a noninvasive technique for detecting lesions after acute subarachnoid hemorrhage. We encountered extravasation on CTA, a finding that has not been reported previously. Three patients with saccular aneurysms showed extravasation on CTA performed within 3 h of the onset of hemorrhage, and all three patients died within 2 weeks. At autopsy, the site of rupture of the aneurysm was confirmed in all three cases. There were two patterns of extravasation shown by CTA, which seemed to depend on the direction of rupture. Extravasation on CTA might represent the natural progression of ruptured aneurysm and may indicate a poor prognosis.

Elevated blood flow resistance in uterine arteries of women with unexplained recurrent pregnancy loss.

BACKGROUND: Uterine perfusion appears to regulate uterine receptivity. However, vascular changes in recurrent pregnancy loss (RPL) remain poorly studied. METHODS: One hundred and twenty one women were enrolled into this study: normal women with sterility caused by male factor (control group: n = 72) and women with RPL (n = 49). Women with uterine anomaly, impaired glucose tolerance, abnormal thyroid function, or anti-phospholipid antibodies were excluded from the study. In the mid-luteal phase of a non-pregnant cycle, transvaginal pulsed Doppler ultrasonography of the uterine artery was performed. Uterine arterial pulsatility index (PI), endometrial thickness, serum estradiol, progesterone, and nitrite/nitrate concentrations were determined. RESULTS: In the RPL group, the PI in the uterine artery of women with antinuclear antibodies was significantly higher than that of women without antinuclear antibodies (P < 0.05). Among women without antinuclear antibodies, the mean (+/-SD) uterine artery PI in the RPL group (2.44 +/- 0.41) was also significantly higher than in the control group (2.19 +/- 0.40; P < 0.01). The PI was inversely correlated with serum progesterone levels (r = -0.47, P < 0.01). CONCLUSIONS: Elevated uterine arterial impedance is associated with RPL. Pulsed Doppler ultrasonography is useful in identifying women with unexplained RPL who have impaired uterine circulation.

Three-directional spectral dispersion for smoothing of a laser irradiance profile.

In inertial confinement fusion research, uniform laser irradiation on a fusion target is a key issue. We propose a new method of beam smoothing in which we use three-directional spectral dispersion to reduce the coherent speckle that is unavoidable in the usual two-directional spectral-dispersion scheme. We have used this smoothing technique in a Nd:glass laser system and have demonstrated that the coherent speckle is reduced by a factor of 2.9 from that in two-directional spectral dispersion.

Blast-wave-sphere interaction using a laser-produced plasma: an experiment motivated by supernova 1987A.

We present x-ray shadowgraphs from a high Mach number ( approximately 20) laboratory environment that simulate outward flowing ejecta matter from supernovae that interact with ambient cloud matter. Using a laser-plastic foil interaction, we generate a "complex" blast wave (a supersonic flow containing forward and reverse shock waves and a contact discontinuity between them) that interacts with a high-density (100 times ambient) sphere. The experimental results, including vorticity localization, compare favorably with two-dimensional axisymmetric hydrodynamic simulations.

Effect of low-intensity warfarin therapy on left atrial thrombus resolution in patients with nonvalvular atrial fibrillation: a transesophageal echocardiographic study.

The presence of left atrial thrombus (LAT) is associated with an increased risk of embolic stroke. However, it has yet to be established definitively whether low-intensity warfarin therapy (INR: 1.5-2.0) can prevent LAT formation in patients with nonvalvular atrial fibrillation (NVAF). The present study analyzed the clinical and transesophageal echocardiography (TEE) features of 123 such patients to identify risk factors for LAT formation and the efficacy of prophylactic low-intensity warfarin therapy. Left atrial thrombi were found in 35 patients (28%) in whom systemic hypertension (49% vs 23%; p<0.01) and ischemic heart disease (17% vs 3%; p<0.01) were more frequent. Left ventricular ejection fraction (54+/-14% vs 60+/-11%; p<0.05), left ventricular end-diastolic dimension (51+/-7 mm vs 48+/-5 mm; p<0.05), spontaneous echo contrast (2.2+/-0.7 vs 1.4+/-0.9; p<0.01), left atrial diameter (50+/-6 mm vs 43+/-7 mm; p<0.01), left atrial appendage blood velocity (22.3+/-8.7 cm/s vs 37.2+/-21.5 cm/s; p<0.01) and the incidence of left ventricular hypertrophy (37% vs 15%; p<0.01) were also significantly different between the groups. Fourteen patients received continuous warfarin therapy (target INR: 1.5-2.0) and on the follow-up TEE study the left atrial thrombus resolved in 10 (71%). There were no thromboembolic events or major hemorrhagic complications in these patients, so it was concluded that low-intensity warfarin therapy is efficacious in treating LAT formation in patients with NVAF.

[Measurement of apparent accommodation with a 20/20 near vision optotype].

PURPOSE: The value of apparent accommodation varies with methods of measurement. To discuss the details of apparent accommodation, it is appropriate to measure it with the smallest possible near vision optotype. In the present study, we used a 20/20 near vision optotype for the measurement of apparent accommodation. SUBJECTS AND METHODS: Forty-six eyes of thirty-eight patients (45-84 years old) who had undergone cataract surgery and intraocular lens implantation, and had at least 20/20 best corrected visual acuity at near and far distances, were used in this study. After the eyes were corrected by glasses to gain the best corrected long distance visual acuity, they were forced to watch a 20/20 near vision optotype. Then we gradually added plus lenses until they could recognize the optotype. The value of apparent accommodation was recorded by subtracting the value of plus lens by which the eye could first recognize the 20/20 near vision optotype from three diopters. RESULTS: The value of apparent accommodation was 0.00-3.00 D (medium 0.50 D). Two eyes had three diopters of apparent accommodation. CONCLUSION: In the present study with correction of astigmatism and small near vision optotype, most eyes showed smaller apparent accommodation than those in previous studies. Despite that, patients with three diopters of apparent accommodation do exist. To analyze high quality visual functions, we should use the smallest possible near vision optotype for the measurement of apparent accommodation.

GnRH agonist-suppressed expression of nitric oxide synthases and generation of peroxynitrite in adenomyosis.

Because overproduction of nitric oxide (NO) and peroxynitrite is known to cause tissue injury, the expression of NO synthases (NOS) and generation of peroxynitrite were investigated in adenomyosis. Immunoreactivities to endothelial and inducible NOS demonstrated phase-dependent changes in normal endometrium, and in eutopic endometrium of adenomyosis. However, NOS were expressed throughout the menstrual cycle in ectopic endometrium from the majority of patients with adenomyosis. Nitrotyrosine, a footprint of peroxynitrite, was detected concomitantly with NOS protein. This suggested that high doses of NO and superoxide are produced in the ectopic endometrium, presumably by stimulation with bioactive molecules such as cytokines and growth factors. The expression of NOS and generation of peroxynitrite were markedly reduced by administration of gonadotrophin-releasing hormone agonists (GnRHa). The suppression of serum concentrations of nitrite/nitrate, stable metabolites of NO, by long-term administration of GnRHa was also demonstrated. The suppression of synthesis of NO and/or peroxynitrite may be part of both the therapeutic and adverse effects of GnRHa therapy.

Three-dimensional computed tomographic angiography in four patients with dissecting aneurysms of the vertebrobasilar system.

BACKGROUND: Recently, three-dimensional computed tomographic angiography (CTA) has been used for the diagnosis and treatment planning of cerebral aneurysm presenting with or without subarachnoid haemorrhage, but the diagnostic value of CTA has not been established. This study evaluated the usefulness of CTA in patients with dissecting aneurysms of the vertebrobasilar system. METHOD: Four patients with acute dissecting aneurysms were examined by CTA, including 3 women and 1 man with a mean age of 60.5 +/- 8.5 years (range: 52-67 years). There were three patients with subarachnoid haemorrhage and one patient presenting with ischaemia. One patient underwent CTA twice and digital subtraction angiography (DSA) once, while one patient had both examinations three times. CTA was performed with a nonionic contrast medium (100 ml of iomeprol 350 mg I/ml) administered via an auto-injector into an antecubital vein at 1.5-1.7 ml/s. To reconstruct three-dimensional images, the volume rendering method was utilized. FINDINGS: All initial CTA studies were performed safely within 5 hours after onset. In patients with subarachnoid haemorrhage, all lesions were demonstrated by finding either the "pearl and string sign" or a "double shadow" on CTA. In the patient presenting with ischaemia, "pearl and string sign" and "double shadow" was shown after the second CTA, and follow-up CTA was able to demonstrate the change of the lesion morphology. All lesions had more irregular luminal surfaces than the non-lesional segments of the involved vessels. INTERPRETATION: CTA was safe in patients with acute vertebrobasilar dissection and demonstrated either the "pearl and string sign" or a "double shadow" which were commonly showed on DSA. An "irregular luminal surface sign" on CTA seems to be one of the characteristics of vertebrobasilar dissection. The view shown by CTA is not less useful than that by DSA to diagnosis and treatment planning in the acute phase of vertebrobasilar dissection, and can also be employed to follow the changes of lesion morphology over time.

Investigation of blood flow in meningothelial and fibrous meningiomas by xenon-enhanced CT scanning.

We investigated whether xenon-enhanced computed tomography was able to separate meningothelial meningioma from fibrous meningioma. Cerebral blood flow was studied by xenon-enhanced computed tomography in six patients with incidentally detected intracranial meningiomas. All of the tumors were small (< 32 mm) and there was little or no peritumoral edema. Three patients had meningothelial meningioma and three patients had fibrous meningioma. The tumor blood flow and the contralateral tissue blood flow were determined. The ratio of these parameters was 1.753 +/- 0.467 for meningothelial meningiomas and 0.809 +/- 0.105 for fibrous meningiomas, with a significant difference between the two tumor subtypes (p = 0.0185). There was no correlation between the signal intensity on magnetic resonance imaging and tumor subtype, and the findings on cerebral angiography also did not indicate the subtype. In conclusion, xenon-enhanced computed tomography showed a difference between smaller meningothelial and fibrous meningiomas in patients with normal surrounding brain tissue. We could not confirm that xenon-enhanced computed tomography was able to distinguish the subtype of meningioma because of the small number of subjects in this study, but our findings might expand interest in the clinical use of this method.

A case of an unclassified tumor closely resembling dysembryoplastic neuroepithelial tumor with rapid growth.

We describe a rare case of a tumor resembling dysembryoplastic neuroepithelial tumor. A 3-year-old girl had a generalized convulsion as the initial symptom, without other neurological deficits. Computed tomography showed a hypodense lesion with calcific hyperdensity in the left frontal lobe associated with deformity of the overlying calvarium. Four months later, she had a second seizure, and computed tomographic scan showed that the lesion had increased in size. Subtotal removal of the tumor was performed, and the postoperative course was uneventful without radiation therapy. Histological examination revealed a cortical lesion in which an oligodendrocyte-like area and an astrocyte-like area with cytological atypia were observed. Although the clinical course and the radiological findings closely resembled those of dysembryoplastic neuroepithelial tumor, specific glioneuronal elements were not found histologically. Daumas-Duport reported a complex form of dysembryoplastic neuroepithelial tumor that contained glial nodules in addition to a specific glioneuronal element. The histological findings of the glial nodules in this case were quite similar to those she described. We conclude that this could be an unclassified tumor closely resembling dysembryoplastic neuroepithelial tumor without a specific glioneuronal element.