Ring and unimodal angular-frequency distribution of THz emission from two-color femtosecond plasma spark.

We study angular and frequency-angular distributions of the terahertz (THz) emission of the low-frequency region (0.3-3 THz) from a two-color femtosecond plasma spark experimentally and in three-dimensional numerical simulations. We investigate the dependence of the angular shapes of the THz radiation on focusing conditions and pulse durations by using two laser facilities (pulse durations 35 and 150 fs) for different focusing geometries. Our experiments and simulations show that decrease in the numerical aperture from NA ≈0.2 to NA ≈0.02 results simultaneously in (I) squeezing of the THz angular distribution and (II) formation of the bright conical emission in the THz range. The moderate focusing NA ≈0.05, which forms the relatively narrow unimodal THz angular distribution, is identified as optimal in terms of angular divergence. Numerical simulations with carrier wave resolved show that bright THz ring structures appear at the frequencies ≥2 THz for longer focuses (NA ≈0.02), while for optimal focusing conditions NA ≈0.05 the conical emission develops at THz frequencies higher than 10 THz.

Ferromagnetic quantum critical point in heavy-fermion iron oxypnictide Ce(Ru(1-x)Fe(x))PO.

We have performed (31)P-NMR measurements on Ce(Ru(1-x)Fe(x))PO in order to investigate ferromagnetic (FM) quantum criticality, since a heavy-fermion (HF) ferromagnet CeRuPO with a two-dimensional structure turns into a HF paramagnet by an isovalent Fe substitution for Ru. We found that Ce(Ru(0.15)Fe(0.85))PO shows critical fluctuations down to ~0.3 K, as well as the continuous suppression of Curie temperature and the ordered moments by the Fe substitution. These experimental results suggest the presence of a FM quantum critical point (QCP) at x~0.86, which is a rare example among itinerant ferromagnets. In addition, we point out that the critical behaviors in Ce(Ru(0.15)Fe(0.85))PO share a similarity with those in YbRh(2)Si(2), where the local criticality of f electrons has been discussed. We reveal that Ce(Ru(1-x)Fe(x))PO is a new system to study FM quantum criticality in HF compounds.

Improved myocardial fatty acid utilization after percutaneous transluminal coronary angioplasty.

Exercise-reinjection 201Tl imaging and resting 20-min and 3-hr BMIPP imaging were performed before and 4 mo after percutaneous transluminal coronary angioplasty (PTCA) in a patient with effort angina. Before PTCA, exercise 201Tl imaging showed decreased 201Tl activity in the septal wall, with significant fill-in on the reinjection 201Tl image. The resting 20-min BMIPP image showed decreased activity in the septal wall, with a slight redistribution on the 3-hr BMIPP image. The 201Tl and BMIPP images 4 mo after PTCA showed significant improvement in the 201Tl pattern and BMIPP uptake in the septal wall with no abnormally decreased activities.

Kinetics of iodine-123-BMIPP in patients with prior myocardial infarction: assessment with dynamic rest and stress images compared with stress thallium-201 SPECT.

UNLABELLED: Myocardial kinetics of 123I-labeled 15-(p-iodophenyl)3R, S-methylpentadecanoic acid (BMIPP) were evaluated with dynamic SPECT, and stress and rest BMIPP images were directly compared in conjunction with stress 201Tl. METHODS: We studied 26 patients with prior myocardial infarction. Two minutes after injection of BMIPP, dynamic data acquisition with a three-headed SPECT was started and continued for 12 min. Conventional SPECT images were obtained at 20 min and 3 hr after injection. On a separate day, exercise, stress 201Tl SPECT was performed at 10 min and 3 hr after injection. Exercise stress-BMIPP imaging was performed in 15 of the patients, and static SPECT images were obtained. RESULTS: With dynamic SPECT, early clearance of BMIPP from the myocardium was observed in the segments with reversible 201Tl defects, suggesting enhanced contribution of backdiffusion from BMIPP. In myocardial segments with reversible 201Tl defects, 20-min BMIPP images showed a higher frequency of reduced uptake when compared to 3-hr 201Tl (90/163) imaging. CONCLUSION: With BMIPP dynamic SPECT, an enhanced contribution of backdiffusion in the early phase from ischemic myocardium was suggested. When exercise stress BMIPP images were obtained, a more severe defect was observed than on rest BMIPP and stress 201Tl imaging, possibly due to decreased coronary blood flow and impaired fatty acid uptake induced by ischemia during exercise.

Early and delayed technetium-99m-tetrofosmin myocardial SPECT compared in normal volunteers.

UNLABELLED: This study was performed to test the feasibility of early SPECT imaging with 99mTc-tetrofosmin with the presence of high hepatic activity. METHODS: Thirteen normal volunteers were injected 600-740 MBq of 99mTc-tetrofosmin at rest and were imaged at 10 min and 1 hr after injection. The SPECT images were reconstructed for 180 degrees 360 degrees data. The early and delayed SPECT and anterior planar projection images were analyzed. RESULTS: After excluding one subject because of high hepatic activity overlapping to the myocardium, 4 of 12 subjects (33%) had abnormal scans with reduced uptake in the inferior wall on the early 180 degrees SPECT image. In contrast, only one (8%) showed equivocally reduced uptake on the 360 degrees SPECT image. In the delayed images, all subjects had a normal 180 degrees and 360 degrees SPECT scan. Quantitative data showed reduced regional activities in the inferior wall on the early SPECT scan, especially in the 180 degrees data. There were no changes in the mean anterior-to-inferior ratio in the anterior planar projection images over time, suggesting that the reduced activity in the early SPECT images reflected an artifactual effect. CONCLUSION: Our data indicate that it would be best to perform late imaging in patients with suspected coronary artery disease using 99mTc-tetrofosmin.

Hemodynamic effects of dibutyryl cyclic AMP in congestive heart failure.

To evaluate the hemodynamic effects of dibutyryl cyclic AMP (DBcAMP) in congestive heart failure (CHF), right-sided cardiac catheterization was performed in 11 patients with CHF, and hemodynamic variables were investigated before and after infusion of various doses of DBcAMP at a rate of 0.025 to 0.2 mg/kg/min (mean 0.14 +/- 0.077 [standard deviation]). DBcAMP reduced total systemic vascular resistance index from 3,171 +/- 1,158 to 1,880 +/- 554 dynes s cm-5 X m2 (mean +/- standard deviation) and pulmonary arterial end-diastolic pressure from 23 +/- 13 to 20 +/- 11 mm Hg, and increased cardiac index from 2.24 +/- 0.60 to 3.41 +/- 1.02 liters/min/m2. Mean arterial blood pressure decreased from 91 +/- 14 to 84 +/- 13 mm Hg, and heart rate increased from 91 +/- 16 to 99 +/- 13 beats/min. The increase in cardiac index was accompanied by a proportional decrease in total systemic vascular resistance index in all patients except 1. In 8 patients the decrease in pulmonary arterial end-diastolic pressure was accompanied by an increase or no change in the left ventricular stroke work index. In 6 patients, DBcAMP was given in incremental doses of 0.05, 0.1, and 0.2 mg/kg/min every 20 minutes, and 5 of 6 patients tolerated the full dose and showed dose-related hemodynamic changes for the incremental doses of DBcAMP. These data suggest that DBcAMP has powerful vasodilating effects on resistance vessels in patients with CHF; hence, it can be a useful vasodilating agent for treatment of CHF.

Efficacy of dibutyryl cyclic AMP in heart failure unresponsive to catecholamines.

The efficacy of dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP) was evaluated in eight patients with heart failure unresponsive to catecholamine therapy. Seven patients who were hemodynamically at Forrester's hemodynamic subset stage H-IV and had a left ventricular stroke work index (LVSWI) of less than 20 g-m/m2 despite administration of unloading drugs and catecholamines were studied both hemodynamically and clinically. Another patient with dilated cardiomyopathy, in whom invasive hemodynamic monitoring could not be carried out, was studied clinically. The DBcAMP was administered intravenously at a mean (+/- SD) of 0.05 +/- 0.036 mg/kg/min, and hemodynamic measurements were made 63 +/- 37 min after administration. The cardiac index (CI) increased from 1.92 +/- 0.22 to 2.49 +/- 0.59 L/min/m2, and LVSWI from 14 +/- 4.0 to 18 +/- 5.1 g-m/m2, both significantly (CI, P less than 0.01; LVSWI, P less than 0.025). The total systemic vascular resistance index (TSVRI) decreased significantly from 2,746 +/- 427.2 to 2,218 +/- 582.6 dan.sec.cm-5.m2 ( P less than 0.01). The increase in CI was accompanied by a proportional decrease in TSVRI in all patients. Left ventricular function, which was estimated by the relation between pulmonary arterial end-diastolic pressure and LVSWI, was improved in five of seven patients after administration of DBcAMP. Two patients in whom DBcAMP was given intermittently improved clinically and survived. The authors conclude that DBcAMP has powerful vasodilating and mild positive inotropic effects and hence can be useful for treating heart failure unresponsive to catecholamines.

Use of morphine and adjuvant drugs according to the condition.

Adjuvant drugs are used to enhance effects of analgesics and morphine-resistant pain such as neuropathic pain. If morphine provides inadequate pain relief and evokes drowsiness, morphine is usually ineffective. The key is the patient's reaction to morphine. When a patient's pain includes neuropathic pain, a combination of morphine and non-steroidal anti-inflammatory drugs is partially effective, but morphine-resistant pain remains. Increasing morphine dosage causes drowsiness without pain improvement. Appropriate adjuvant drugs are necessary in these conditions.

MR sialography in patients with Sjögren syndrome.

PURPOSE: The purpose of this study was to evaluate the effectiveness of MR sialography of the parotid gland ducts in the diagnosis and staging of Sjögren syndrome. METHODS: MR imaging was performed on a 1.5-T unit with a neck phased-array coil. MR sialographic source images were obtained using a heavily T2-weighted fast spin-echo sequence with spectral fat suppression. All images were analyzed on the basis of maximum intensity projection reconstruction. Five healthy control subjects and 51 patients with definite Sjögren syndrome (43 with primary disease and eight with secondary disease) were examined with MR sialography. A labial gland biopsy was performed in all patients and histopathologic grading was done by means of focal scores. The findings of MR sialography were compared with the results of labial gland biopsy to determine the effectiveness of the technique in the diagnosis and staging of Sjögren syndrome. RESULTS: In all five control subjects, the main duct and the primary branching ducts of the parotid glands were clearly visible on MR sialographic images. In patients with Sjögren syndrome, a punctate, globular, cavitary, or destructive appearance was well seen within the parotid glands. Findings obtained at MR sialography correlated well with the results of labial gland biopsy. CONCLUSION: MR sialography has the potential to produce diagnostic findings in the parotid gland ducts of patients with Sjögren syndrome. Our results suggest that this method will augment and possibly replace X-ray sialography.

Dose calculation for asymmetric photon fields with independent jaws and multileaf collimators.

We have developed a simple method for dose calculation in dual asymmetric open and irregular fields with four independent jaws and multileaf collimators. Our calculation method extends the scatter correction method of Kwa et al. [Med. Phys. 21, 1599-1604 (1994)] based on the principle of Day's equivalent-field calculation. The scatter correction factor was determined by the ratio of the derived doses of a smaller asymmetric open field or irregular field to a larger symmetric field. The algorithm with the scatter correction method can be calculated from output factors, tissue maximum ratios, and off-axis ratios for conventional symmetric fields. The doses calculated by this method were compared with the measured doses for various asymmetric open and irregular fields. The agreement between the calculated and measured doses for 4 and 10 MV photon beams was within 0.5% at the geometric center of the asymmetric open fields. For the asymmetric irregular fields with the same geometrical center, agreement within 1% was found in most cases.

Treatment of postoperative pain with thoracic epidural morphine in oral malignant tumor patients.

CASE REPORT: Thoracic epidural morphine was administered to five patients who underwent radical resection and reconstructive surgery for oral malignant tumors. METHODS AND RESULTS: In case 1, an epidural catheter was inserted at the T3-T4 interspace, and 4 mg morphine was administered through the catheter approximately 5 h before the end of surgery. Forty-five minutes after the end of surgery, a total of 10 mg morphine was continuously infused over a 2-day period using a balloon infusion system. The patient did not complain of pain, and no other analgesics were necessary. There were no serious side effects throughout the treatment of postoperative pain. Good control of pain was obtained by this method in four similar cases. CONCLUSION: Thoracic epidural morphine was effective in the relief of postoperative pain following oral surgery in five cases.

Experimental intraocular lens implantation in the rabbit eye and in the mouse peritoneal space. Part I: Cellular components observed on the implanted lens surface.

Polymethylmethacrylate and silicone intraocular lenses (IOLs) were implanted in the rabbit eye and in the mouse peritoneal space to study cellular response to the implanted IOL. Animals were sacrificed at various times after implantation. The removed IOLs were properly fixed and stained using Wolter's implant cytology technique. Scanning and transmission electron microscopic studies were performed. Macrophages, lymphocytes, and fibroblast-like cells were the major components identified. Occasional formations of foreign-body giant cells were seen. The responses observed on IOLs implanted in the rabbit eye were generally milder than those observed on IOLs implanted in the mouse peritoneal space.

Experimental intraocular lens implantation in the rabbit eye and in the mouse peritoneal space. Part II: Morphological stages of the macrophage on the implanted lens surface.

Macrophages appearing on implanted intraocular lenses (IOLs) in the rabbit eye and in the mouse peritoneal space were observed using Wolter's implant cytology staining and scanning and transmission electron microscopy. In response to the implanted IOL, macrophages in the mouse peritoneal space displayed an activated form with marked ruffles on the surface. They were attached to the IOL with a broad base (sessile macrophage). The macrophages metamorphosed gradually to the flat shape of so-called epithelioid cells with many processes. They showed a tendency to fuse together or become more flat by extending the cytoplasmic lamellipodia and finally disappeared, leaving a thin membrane or a fibrous matrix. Phagocytic activity of macrophages and related cells was also observed. However, those observed on the IOL implanted in the rabbit eye showed less surface structure and appeared to adhere weakly to the IOL.

Experimental intraocular lens implantation in the rabbit eye and in the mouse peritoneal space. Part III: Giant cell formation on the implanted lens surface.

Among the cell components appearing on an implanted intraocular lens (IOL), the macrophage is the most active participant in the foreign-body response. The morphological stages of the macrophage in the response include not only an activated form and a flat epithelioid cell, but also a giant cell observed in the later stage of the response. The giant cells on the IOLs implanted in the rabbit eye and in the mouse peritoneal space were investigated by means of Wolter's implant cytology staining and scanning and transmission electron microscopic observation. Differences in the two biological environments as the site of IOL implantation are discussed.

Experimental intraocular lens implantation in the rabbit eye and in the mouse peritoneal space. Part IV: Cell adhesion, fibroblast-like cell, and lymphocytic cluster observed on the implanted lens surface.

Transmission and scanning electron microscopy, Wolter's implant cytology staining, and an immunohistochemical method were used to investigate the process of cell adhesion, the origin of fibroblast-like cells, and the nature of lymphocytic clusters that were observed on intraocular lenses (IOLs) experimentally implanted in the rabbit eye and in the mouse peritoneal space. On the IOL implanted in the mouse peritoneal space, pseudopodia extended during cell adhesion showed morphological variety; on the IOL implanted in the rabbit eye, membranous extensions were seen. Many of the fibroblast-like cells exhibited positive staining for macrophagic antigen, indicating a macrophagic origin. The build-up of lymphocytic clusters, as an indicator of immunologic activity, was frequently observed on IOLs implanted in the mouse peritoneal space, particularly on silicone IOLs. However, such clusters were rarely seen on poly(methyl methacrylate) or silicone IOLs implanted in the rabbit eye, suggesting a much reduced immune response to those materials in the eye chamber.

Wall correction factors for calibration of plane-parallel ionization chambers with high-energy photon beams.

Most dosimetry protocols recommend that calibration of plane-parallel ionization chambers be performed in an electron beam of sufficiently high energy by comparison with cylindrical chambers. For various plane-parallel chambers, the 1997 IAEA TRS-381 protocol includes an overall perturbation factor pQ for electron beams, a wall correction factor p(wall) for a 60Co beam and the product of two wall corrections k(att)k(m) for 60Co in-air calibration. The recommended values of p(wall) for plane-parallel chambers, however, are limited to certain phantom materials and a 60Co beam, and are not given for other phantom materials and x-ray beams. In this work, the p(wall) values of the commercially available NACP, PTW/Markus and PTW/Roos plane-parallel chambers in a solid water phantom have been determined with 60Co and 4 and 10 MV photon beams. The k(att)k(m) values for the NACP and PTW/Markus chambers have also been obtained. The wall correction factors p(wall) and k(att)k(m) have been determined by intercomparison with a calibrated Farmer chamber. The average value of p(wall) for these plane-parallel chambers was 1.005 +/- 0.1% (1 SD) for 60Co beams and 1.007 +/- 0.2% (1 SD) for both 4 MV and 10 MV photons. The k(att)k(m) values for the NACP and PTW/Markus chambers were about 1.5% lower than other published data.

Properties of G-protein modulated receptor-adenylyl cyclase system in myocardium of spontaneously hypertensive rats treated with adriamycin.

Properties of the receptor--G protein--adenylyl cyclase system were studied in spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats (WKY) treated with adriamycin (ADR, 1 mg/kg per week) for 12 weeks. An identical dosing schedule caused a significantly greater decline in body weight gain and a marked elevation of plasma norepinephrine level in SHR than in WKY. A significant increase in the messenger RNA encoding Gi-alpha 2 was found in SHR+ADR group. The activity of the adenylyl cyclase stimulated by guanyliminodiphosphate [Gpp(NH)p] was decreased by 49% in SHR and 73% in SHR+ADR. However, stimulated activities of adenylyl cyclase by both sodium fluoride and forskolin remained unchanged. Functional level of stimulatory G-protein (Gs) as measured by reconstitution assay in sarcolemmal membrane was unaltered among different groups. Furthermore, the density of beta-adrenoceptor was significantly decreased without change of its affinity. Muscarinic receptors exhibited a three-site affinity distribution in SHR+ADR whereas other groups displayed only two-site affinity distribution. These results suggest that SHR exhibited a depressed myocardial adenylyl cyclase signaling system which may not be due to the functional uncoupling of beta-adrenoceptors from Gs but to the increased inhibitory G-protein (Gi) activity as demonstrated by the increased mRNA of Gi-alpha 2, increased inhibition of Gpp(NH)p-mediated adenylyl cyclase and the super high affinity for carbachol of the muscarinic receptors. Decreased beta-adrenoceptor density and functional alteration of Gi might be regarded as the predisposing factors for the increased susceptibility of myocardium of SHR to ADR.

Post-infectious leukoencephalopathy as a complication of Mycoplasma pneumoniae infection.

We report a 9-year-old girl with leukoencephalopathy who demonstrated serologic evidence of a Mycoplasma pneumoniae infection. She had a mild upper respiratory tract illness 10 days prior to admission and developed walking difficulty and somnolence. The neurologic symptoms progressed to semicoma and spastic paraplegia over a few days but began to improve on the fourth day. Cranial computed tomography on the eleventh day revealed an area of diffuse low density in the white matter. Cerebrospinal fluid examination was normal. The patient recovered with minimal motor deficits. Cranial computed tomography was normal. She was diagnosed as having leukoencephalopathy complicated by a Mycoplasma pneumoniae infection. The pathogenesis of this infection is believed to be an allergic reaction to Mycoplasma pneumonia of the central nervous system as well as an acute disseminated encephalomyelitis.

Relationship between various parameters derived from 123I-labelled beta-methyl-branched fatty acid whole-body scintigraphy and left ventricular ejection fraction in patients with ischaemic heart disease.

Heart uptake and clearance of 123I-15-(p-iodophenyl)-3(R,S)-methyl- pentadecanoic acid (BMIPP) by whole-body scintigraphy in relation to left ventricular ejection fraction (LVEF) was evaluated in 34 patients with ischaemic heart disease. At 45 and 210 min after injection, anterior whole-body images were obtained. In each patient, multigated blood pool scintigraphy was also performed, and LVEF was calculated. The percentage heart uptake of BMIPP did not have a significant correlation with LVEF (R = -0.299, NS). In contrast, there was a positive correlation between LVEF measured by multigated blood pool scintigraphy and BMIPP count density of the heart (R = 0.467, P = 0.005). Myocardial BMIPP washout rate also positively correlated with LVEF (R = 0.472, P = 0.005). In addition to these observations, there was a positive correlation between the BMIPP count density of the heart and myocardial BMIPP washout rate (R = 0.0543, P = 0.001). Thus, the BMIPP count density of the heart and myocardial BMIPP washout rate derived from BMIPP whole-body scintigraphy directly correlated with LVEF. However, the correlations between these parameters and LVEF were not strong enough to allow left ventricular dysfunction to be assessed precisely.

Urinary carnitine excretion in patients with heart failure.

To evaluate the fatty acid metabolism in heart failure, the semiquantitative analysis of urinary free carnitine and acylcarnitine was made by fast atom bombardment mass spectrometry (FABMS) in 22 patients (mean age 67.3 years) with heart failure and 19 age-matched healthy controls (average age 60.4 years). Urinary excretion of free carnitine was 0.20 +/- 0.118 ratio/mg creatinine in the healthy controls and 1.32 +/- 1.170 ratio/mg creatinine in the patients with heart failure. The latter value was significantly higher (p < 0.01). Patients with heart failure were classified into two groups according to the urinary free carnitine concentration. One was the high excretion group (2.19 +/- 0.102 ratio/mg creatinine, 12 cases) and the other was the low excretion group (0.37 +/- 0.212 ratio/mg creatinine, 10 cases). In the high excretion group, urinary acetylcarnitine was also increased, but no significant abnormalities were observed in the urinary organic acid profile. In the high group, 1 patient was classified as NYHA class III and 11 as NYHA class IV. Four patients died in the hospital. In the low excretion group, five patients were classified as NYHA class III and five as NYHA class IV. Only one patient died in the hospital. In the high group, patients with severe and prolonged heart failure tended to maintain higher values of urinary free carnitine. We could not find any abnormalities in fatty acid metabolism in patients with heart failure, but it is suspected that the patients who excrete large amounts of free carnitine into the urine, namely the patients with severe heart failure, have some possibility of carnitine deficiency.