Surgically excised primary mediastinal tumors and cysts: a report of 43 cases

Forty-three primary mediastinal tumors or cysts were surgically treated in 41 patients during a 10-year period. These tumors consisted of 20 thymic tumors, 10 neurogenic tumors, 5 teratomas, 3 lymphoid tumors, 2 congenital cysts, 2 mediastinal thyroid tumors, and 1 chondroma. There were 16 male and 25 female patients. The mean age was 44 years with a range of 6 to 79 years. Sixteen patients (39%) were symptomatic. There were 20 thymic tumors including 13 thymomas, 5 thymic cysts, and 2 hyperplasia with myastenia. Additional radiation therapy was recommended for all but stage I thymomas. Only 1 of the 10 neurogenic tumors was malignant. Eight teratomas were all cystic and matured. Early operative intervention is mandatory in these cases.     

Edge density profile variation during a magnetic axis shift in the CHS heliotron/torsatron

Edge density profiles were measured during natural and forced magnetic axis shifts in the lowaspect-ratio heliotron/torsatron CHS, using an 8 keV fast neutral lithium beam probe. The Shafranov shift of the magnetic axis (and hence the dislocation of the LCFS) that was negligible for a low density ECH discharge became substantial (4.5 cm) for a high density NBI discharge (n _e2.5× 10¹³cm^–3) and the corresponding radius of the LCFS increased about 1.2 cm in major radius compared to the vacuum case. For NBI discharges with different settings of the vacuum magnetic axisR _ax (fixed during the discharge), the measured edge density profiles indicated reasonable agreement between the theoretically and experimentally obtained LCFS radii for 90 cm <R _ax<101.6cm, while forR _ax<90 cm the measured radius was 10% larger than expected. When a change ofR _ax from 94.7 cm to 89.9 cm during a discharge was imposed externally, a well behaved plasma boundary moved inward smoothly by about 7.5 cm, while the steepness of the edge density profile changed for different values ofR _ax. The steepest profile was attained forR _ax=92.1 cm when the highest energy content and average density were achieved.     

Acute necrotizing gastritis associated with adult T-cell leukemia in the course of chemotherapy

A 63-year-old man with smoldering adult T-cell leukemia (ATL) which became acute was admitted. During chemotherapy, he experienced epigastric pain and fever due to neutropenia. The combination therapy of antimicrobials and rhG-CSF was ineffective and he died. Autopsy revealed systemic invasion of ATL cells. The stomach findings resembled those of phlegmonous gastritis, a rare form of bacterial gastritis, along with diffuse, mucosal necrosis with hemorrhage. The pathogenesis of necrotizing gastritis remains to be elucidated. The patient had also received histamine H2 antagonist for gastric ulceration, which might have influenced the gastric bacterial flora.     

The GABAA receptor is expressed in human neurons derived from a teratocarcinoma cell line

NT2 cells, a human teratocarcinoma cell line, are shown to be differentiated in neuron-like cells (NT2-N cells) by treatment with retinoic acid. The present study identified the neurotransmitter receptors expressed in NT2-N cells using patch-clamp recording. Voltage-sensitive Na+ currents, which are specific for neurons, were observed in NT2-N cells but not in NT2 cells, suggesting that NT2-N cells actually function as neurons. Glutamate receptor agonists, N-methyl-D-aspartate (NMDA) and kainate, evoked whole-cell currents. In addition, gamma-aminobutyric acid (GABA) evoked currents and the currents were inhibited by the selective GABAA receptor antagonist, bicuculline. In outside-out patches, GABA elicited single channel currents with two classes of the slope conductance (26 and 50 pS). No current, however, was induced by ACh, serotonin, or dopamine NT2-N cells, thus, express at least two types of the major excitatory and inhibitory neurotransmitter receptor in the central nervous system, the glutamate and GAGAA receptors, suggesting that these receptors have a crucial role in neurotransmission from the earlier stage of the brain development.     

Involvement of SNAP-25 in TRH-induced exocytosis in pituitary GH4C1 cells

The synaptic membrane protein synaptosomal-associated protein (SNAP-25) has recently been implicated as one of the key proteins involved in exocytotic membrane fusion in neurons. However, the role of SNAP-25 in pituitary hormone release is not known. In this study, we determined that SNAP-25 is involved in regulated exocytosis in the clonal pituitary cell line GH4C1. SNAP-25 messenger RNA and protein were detected in GH4C1 cells by RT-PCR and immunoblot analysis, respectively. Immunofluorescence analysis indicated that SNAP-25 protein was localized in the plasma membrane. Next, to determine the function of SNAP-25 in GH4C1 cells, specific inhibitors of SNAP-25, botulinum neurotoxin (BoNT)/A or /E, and antisense SNAP-25 oligonucleotide were used. Neither BoNT/A nor BoNT/E affected thyrotropin-releasing hormone (TRH)-induced cytosolic Ca2+ increase, but both inhibited TRH-induced exocytosis. Moreover, they dose-dependently inhibited TRH-induced prolactin release. The introduction of antisense oligonucleotide into the cells also inhibited TRH-induced prolactin release. These results suggest that SNAP-25 is involved in regulated exocytosis in GH4C1 cells.     

Renal depressor mechanisms of physical training in patients with essential hypertension

To clarify characteristics of the patients in whom exercise training lowers blood pressure and to elucidate the mechanisms by which exercise training lowers blood pressure, we evaluated 24-h blood pressure, glomerular filtration rate (GFR), renal blood flow (RBF), filtration fraction (FF), plasma renin activity (PRA), plasma aldosterone concentration (PAC), plasma norepinephrine concentration (PNE), and incremental area of insulin/glucose (sigmaI/sigmaG) during 75 g oral glucose tolerance test, and assessed arterial baroreceptor function (BSI) before and after a 3-week exercise training program (four 6-min sessions daily at 75% VO2 max). Patients were classified as responders (n = 15) if they showed statistically significant reduction in the multiple comparison of 24-h mean arterial pressure (MAP), or as nonresponders (n = 15) if they did not. Although there were no significant differences between responders and nonresponders in age, weight, MAP, GFR, RBF, RPF, FF, PNE, sigmaI/sigmaG, or BSI before exercise, renal vascular resistance (RVR; P < .05), PRA (P < .05), and PAC (P < .05) were significantly higher in responders than in nonresponders. The fractional excretion of sodium (FENa) (P < .05) were significantly lower in responders than in nonresponders. After exercise training, FF (P < .01), RVR (P < .05), PNE (P < .05) PRA (P < .01), and sigmaI/sigmaG (P < .05) decreased significantly only in responders. The decrease in MAP significantly correlated with the reductions in FF (r = 0.46, P < .05), PNE (r = 0.52, P < .01) and RVR (r = 0.40, P < .05). Thus, in patients who have higher RVR and PRA, exercise training lowered blood pressure in parallel to a reduction in RVR associated with decreases in sympathetic tone and improvement of insulin resistance. Our results suggest that exercise-induced changes in renal hemodynamics may contribute to the reduction in blood pressure in these patients.     

Improvement of gigacycle fatigue properties by modified ausforming in 1600 and 2000 MPA-class low-alloy steels

Fatigue tests were conducted for a modified ausformed and tempered JIS-SCM440 low-alloy (denoted as AF) steel with tensile strengths of 1600 and 2000 MPa, respectively, and were compared with normally quenched and tempered (QT) steel. The 1600 MPa-class modified ausformed steel (AF1600) developed no fish-eye fractures and a fatigue limit of 920 MPa, whereas normally quenched steel (QT1600) developed fish-eye fractures and showed a lower fatigue limit of 840 MPa. The 2000 MPa-class modified ausformed steel (AF2000) achieved a high fatigue limit of 1010 MPa, but developed fish-eye fractures. The fatigue limit of normally quenched steel (QT2000) was 840 MPa. Results of fatigue tests at 20 kHz up to 10⁹ and 10¹⁰ cycles agreed with the fatigue limits for QT1600 and QT2000, respectively. The fracture sites of fish-eye fractures in QT1600 were Al₂O₃ and TiN inclusions, and those in AF2000 and QT2000 were Al₂O₃ and TiN inclusions and internal facets. Fracture surfaces of QT2000 that broke at over 10⁷ cycles had large, clearly identifiable optically dark areas (ODAs). The AF2000 showed no fractures over 10⁷ cycles, and the authors could not conclude whether the fracture surface of the specimens broken at around 5 × 10⁶ cycles had ODAs. The fact that long-life fatigue failure over 10⁷ cycles did not occur in AF2000 showed that ODAs did not form in this steel, since ODAs developed in proportion to cycle number and became large and clearly identifiable at over 10⁷ cycles. Their incidence was quantitatively demonstrated by modified Stress amplitude vs Number of cycles to failure (S-N) diagram analysis. The modified S-N curve for AF2000, in which the specimens were assumed to have no ODAs, showed good agreement with that for QT2000, in which ODAs were assumed to be formed, especially at over 10⁷ cycles.