Quantitative assessment of digitized portal images: effect of sampling frequency on observer performance.

To investigate spatial resolution requirements for digitized portal images in radiation therapy, observer performance tests were performed. One hundred twenty portal images were digitized with sampling frequencies of 0.700, 0.350, and 0.175 mm for observation. Receiver operating characteristic analysis was used to determine the acceptable sampling frequency for clinical portal images. The detectability of setup errors was significantly better on the original images than on the digitized images with sampling frequencies of 0.700 mm (P = .005) and 0.350 (P = .046). Some clinical disadvantages might accrue with the use of a sampling frequency of 0.350 mm or larger.     

Migraine is associated with enhanced arterial stiffness.

Migraine is a common subtype of headache. Epidemiological studies have revealed that migraine could be an independent risk factor for ischemic stroke even in elderly subjects. Arterial stiffness is one of the major pathophysiological bases of stroke. In the present study, we cross-sectionally investigated the possible relationship between migraine and arterial stiffness in community-dwelling subjects. The study subjects were independently recruited from two sources (Group A, n=134, 68+/-5 years; Group B, n=138, 68+/-7 years). Augmentation index (AI), the ratio of augmented pressure by the reflection pressure wave to the pulse pressure, was obtained from the radial arterial waveform as an index of arterial stiffness. Brachial blood pressure was also measured simultaneously. Migraine was diagnosed using a previously validated questionnaire. The prevalence of migraine was 5.2% (Group A) and 16.7% (Group B). Subjects with migraine had higher radial AI in both Group A (migraine, 101+/-15%; other headache, 88+/-12%; no headache, 86+/-12%, p=0.003) and Group B (95+/-11%, 90+/-11%, 91+/-14%, p=0.058). Multiple linear regression analysis revealed that migraine was an independent determinant of AI (beta=0.154, p=0.002) after adjustment for other confounding factors: age (beta=-0.024, p=0.654); sex (beta=0.141, p=0.069); body height (beta=-0.215, p=0.005); systolic blood pressure (beta=0.174, p=0.001); medication for hypertension, hyperlipidemia, and diabetes mellitus (beta=-0.014, p=0.787); and heart rate (beta=-0.539, p<0.001). In a separate analysis by sex, migraine was also a significant determinant for AI (male, beta=0.246, p=0.019; female, beta=0.159, p=0.008). Migraine in the elderly could be a clinical manifestation of enhanced arterial stiffness.     

Effect of gravitation for detection of bronchioloalveolar carcinoma on computed tomography

A 64-year-old female was found to have localized ground-glass opacity (GGO) in the middle lobe on a chest computed tomography (CT) for screening. Middle lobectomy with video-assisted thoracoscopic surgery (VATS) was undertaken, and pathological diagnosis was a bronchioloalveolar carcinoma (BAC) in stage IA. A follow-up CT a year following the surgery revealed localized GGO in area S⁶ of the left lung. However, it disappeared during the gravitation-dependent gradient in the observation period. The patient was scanned again under prone position to exclude the gravitational effect, resulting in definite detection of the GGO. Left extended S⁶ segmentectomy with VATS was performed, and pathological diagnosis was a BAC in stage IA. As GGO existing in a gravitation-dependent area may be masked by the gravitation-dependent density, a change of the scanning position may lead to a proper detection of the tumor for the diagnosis of BAC.     

Preoperative identification of subthalamic nucleus for deep brain stimulation using three-dimensional phase sensitive inversion recovery technique.

PURPOSE: We assessed the feasibility of utilizing three-dimensional (3D) phase sensitive inversion recovery (IR) images for preoperatively determining deep brain stimulator position. METHODS: We measured geometric distortion with a grid phantom and evaluated images of 3 volunteers to determine optimum imaging parameters for 3D phase sensitive IR. RESULTS: Geometric distortion measured less than 1.0%. Respective inversion and recovery times, which provided high T(1) contrast between the subthalamic nucleus and adjacent tissue, were 200 and 4000 ms. In studies of 3 volunteers and 2 patients, the subthalamic nucleus was clearly depicted in 3D phase sensitive IR images. The measured coordinates of the subthalamic nucleus agreed well with those calculated by conventional estimation from midpoint of the anterior and posterior commissure. CONCLUSION: Three-dimensional phase sensitive inversion recovery was useful in visualizing the subthalamic nucleus for effective deep brain stimulation.     

Comparison of intestinal and peritoneal dialysis of theophylline and phenobarbitone in rats

Intestinal dialysis of drugs by oral administration of activated charcoal has been compared with peritoneal dialysis in rats. The average amounts of theophylline transported over 120 min into the intestinal lumen and the peritoneal cavity were 15.7 and 16.5% of the intravenous dose (10 mg kg-1), respectively, showing no significant difference, whereas the amount of the same intravenous dose of phenobarbitone transported from the blood into the intestinal lumen (7.8%) was significantly smaller than that entering the peritoneal cavity (12.5%). The net water flux showed that secretion predominated in the peritoneal transport whilst absorption predominated in the intestinal transport for both drugs. However, the net water flux in the intestinal lumen after intravenous theophylline (as aminophylline) was significantly smaller than that following phenobarbitone. The differences in transport across the two membranes could be due to differences in the intrinsic properties of the could be due to differences in the intrinsic properties of the membranes, such as the surface area, the thickness of the membrane and the distribution of blood vessels. Differences could also be due to differences in the pharmacological effects of the drugs.     

Pituitary metastasis of thyroid follicular adenocarcinoma--case report.

A rare case of pituitary metastasis of thyroid follicular adenocarcinoma occurred in a 62-year-old female manifesting as left retro-orbital pain and diplopia. Computed tomography and magnetic resonance imaging revealed a tumor in the pituitary fossa extending to the left cavernous sinus, sphenoid sinus, and prepontine cistern, destroying the upper portion of the clivus. An asymptomatic thyroid mass, probably malignant, was also found. She also had an incidental small meningioma in the posterior fossa. The pituitary tumor was partially removed, and the thyroid and posterior fossa tumors were totally removed in two operations. Both pituitary and thyroid tumors were verified to be follicular adenocarcinoma. Postoperatively, she developed panhypopituitarism for which cortisol and thyroxine replacement therapy was necessary. Three years after first therapy, she was alive but her symptoms did not improve.     

Roles of kallikrein-kinin system in acute inflammation: studies on high- and low-molecular weight kininogens-deficient rats (B/N-Katholiek strain)

Carrageenin-induced paw edema in HMW- and LMW-kininogens-deficient rats was significantly less than that in normal rats. There are three kininogens, HMW-, LMW- and T-kininogens, in normal rat plasma, but B/N-Katholiek rat plasma contains only T-kininogen. The pretreatment with captopril, a kiniase II inhibitor, enhanced paw swelling of normal rats, but not that of the deficient rats, indicating that bradykinin released from HMW-kininogen may have a role for the swelling but T-kinin may not be released in this inflammation.     

Tetronothiodin, a novel CCKB receptor ligand, antagonizes cholecystokinin-induced Ca2+ mobilization in a pituitary cell line.

We found a novel nonpeptide CCKB receptor antagonist, tetronothiodin (Ro 09-1468), in the culture broth of Streptomyces sp. NR0489. The structure of the compound (C31O8H38S), which has a 19-membered ring with an alpha-acyltetronic acid and tetrahydrothiophene moiety, is completely different from that of any known CCK receptor antagonist. Tetronothiodin inhibited [125I]CCK-8 binding to rat brain CCKB receptors with an IC50 of 3.6 nM, whereas it showed only weak affinity for rat CCKA receptors (IC50 = 70 microM). As demonstrated autoradiographically, tetronothiodin concentration dependently inhibited [125I]CCK-8 binding to CCKB receptors in rat forebrain slices. The effects of tetronothiodin on cytosolic Ca2+ concentrations in GH3 cells, a rat anterior pituitary tumor cell line, were investigated with the fura-2 method. Tetronothiodin inhibited CCK-8-induced Ca2+ mobilization without affecting basal cytosolic Ca2+ concentrations. In conclusion, tetronothiodin is a new, potent and highly selective CCKB receptor antagonist. It is a useful tool for investigating the pharmacological and physiological roles of CCKB receptors.     

Analysis of T Cell Receptor Variability in Fresh Tumor-infiltrating Lymphocytes from Human Head and Neck Cancer

In this study, we analyzed T cell receptor (TCR) gene rearrangements in tumor-infiltrating lymphocytes (TIL) freshly obtained from 15 patients with head and neck cancer using the reversely transcribed polymerase chain reaction (RT-PCR) method. These TILs showed preferential expression of Vα10, Vα8 and Vα1, detected in 13 (87%), 11 (73%), and 9 cases (60%), respectively. The TCRVβ gene revealed diversity without preferential usage. The head and neck region is exposed to bacteria and viruses, so it is possible that the tumor site can become infected and accumulate T cells involved in infection and inflammation. Therefore, we also investigated TCR gene usage in T cells infiltrating in chronic sinusitis mucosa to address the question of whether the Vα1, Vα8, and Vα10 subfamilies are characteristic in TIL from squamous cell carcinoma of head and neck. TCR Vα10 gene usage was also the most common in Vα segment in T cells infiltrating the sinus mucosa, but Vα and Vα8 were not detected in the T cells in sinusitis. These results indicate that the Vα10 subfamily, the preferred T cell population in both TIL and T cells in inflammatory disease, might he involved mainly in inflammation or infection. On the other hand, Vα1 and Vα8 appear to be relatively specific populations for antitumor immunity in head and neck cancer.     

Comparison of [I]metaiodobenzylguanidine kinetics with heart rate variability and plasma norepinephrine level

Background. [¹²³I]Metaiodobenzylguanidine (MIBG) imaging has been used to assess cardiac sympathetic nerve abnormalities. We evaluated the clinical significance of myocardial MIBG imaging as a measure of cardiac sympathetic nervous system function by comparing it to heart rate variability and plasma norepinephrine level.Methods and Results. In 211 subjects, we analyzed heart rate variability with 24-hour electrocardiography, performed scintigraphy with MIBG, and measured plasma norepinephrine levels. Time and frequency domain measures of heart rate variability were calculated with the Marquette heart rate variability program (Marquette Electronics, Milwaukee, Wis.). Early and late myocardial MIBG uptakes were measured at 15 and 150 minutes after injection, respectively. MIBG clearance rate from the heart and heart-to-lung and heart-to-mediastinum ratios of MIBG activities were calculated. On the whole, heart rate variability, including low-frequency power, correlated positively, but modestly so, with late MIBG uptake and negatively with MIBG clearance rate. The plasma norepinephrine level correlated negatively with late MIBG uptake and with heart rate variability, including low-frequency power, and positively with MIBG clearance rate. Similar correlations were also observed in patient subgroups with coronary artery disease, diabetes mellitus, and renal failure, but these correlations were weak (R² < 0.5).Conclusions. Increased cardiac sympathetic nervous system activity may be associated with increased myocardial MIBG clearance and decreased heart rate variability, including low-frequency power. Because these associations were not strong, however, the combination of heart rate variability with MIBG may allow an interactive assessment of the cardiac autonomic nervous system.