Combined study with FDG PET and Tl SPECT in patients with idiopathic dilated cardiomyopathy

This study aimed to determine whether combined examinations of myocardial 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) and stress-redistribution 201Tl single-photon emission computed tomography (Tl SPECT) were useful in clarifying myocardial ischaemia and evaluating the prognosis in patients with idiopathic dilated cardiomyopathy (IDCM). Twenty-two patients with IDCM underwent echocardiography, cardiac catheterization, FDG PET, and Tl SPECT. In scintigraphic analysis, the total defect score (TDS) was semiquantitatively determined as the sum of scores of the 17 left ventricular (LV) segments with a 5-point scale (0 as normal to 4 as absent). Patients were classified according to the scintigraphic findings as follows: eight patients with small defects on Tl and FDG (TDS < or = 20) (group I), eight patients with small defects on FDG (TDS < or = 20) with FDG uptake increased relative to Tl or 'mismatch' (group II), and six patients with large defects on FDG and Tl (TDS >20) (group III). Eleven patients (50%) showed reversible defects on Tl and all showed preserved FDG uptake. The patients in group III had significantly lower LV ejection fraction (LVEF) (P<0.05, respectively) and a poorer prognosis as shown by the Kaplan-Meier event-free curve compared with those in groups I and II (P<0.01, respectively). Although patients in group II had significantly greater TDS on Tl compared with those in group I (P<0.01), no significant differences in LVEF and prognosis were found between patients in groups I and II. In multivariate analysis, a TDS on FDG revealed an independent predictor of subsequent cardiac events. In conclusion, such mismatched areas can be assumed to consist of impaired but viable myocardium, and may be associated with ischaemia of the microvasculature. Impaired myocardial glucose metabolism is a more powerful predictor of future cardiac events than perfusion abnormality in patients with IDCM.     

A 3.3-V 12-ns 16-Mb CMOS SRAM

A 16-Mb CMOS SRAM having an access time of 12 ns under a 3.3-V supply has been developed with a 0.4-μm process technology. An address access time of 12 ns has been achieved by an optimized architecture, the use of an automated transistor size optimizer, and a read-bus midlevel preset scheme (RBMIPS). For better yield and efficient testing, an on-chip test circuit with three test modes has been implemented     

Protective effect of prostaglandin E2 on cerulein-induced rat pancreatitis]

In order to clarify the effect of prostaglandin E2 (PGE2) on cerulein-induced rat pancreatitis, we investigated the interaction of PGE2 with cerulein or secretin. Intravenous infusion of 10 micrograms/kg.h cerulein inhibited external secretion of the pancreas from one hour and caused macroscopic edema at 3 hours. Administration of PGE2 relieved the inhibitory effect of supramaximal dose of cerulein and decreased the pancreatic edema. The 100 micrograms/kg.hr PGE2 had no significant effect on the pancreatic juice volume and amylase secretion stimulated with 0.2 micrograms/kg.hr of cerulein. Intravenous injection of 100 micrograms/kg PGE2 inhibited both the volume and amylase secretion of pancreatic juice stimulated with 1 U/kg.h of secretin. The protective effect of PGE2 on cerulein-induced pancreatitis was not the stimulation on secretion but caused the cytoprotective effect of PG such as stabilization of cytoplasmic and lysosomal membrane.     

Effects of ventilation and pleural effusion on measurements of airway thermal volume and blood flow in dog lungs

We studied the effects of ventilation and pleural effusion on measurements of airway thermal volume (ATV) and pulmonary blood flow (PBF) by using the airway gas thermometry method of V. B. Serikov, M. S. Rumm, K. Kambara, M. I. Bootomo, A. R. Osmack, and N. C. Staub (J. Appl. Physiol. 72: 944-953, 1992) in 39 anesthetized dogs with or without lung edema or pleural effusion. To examine the differential effects of increased-pressure and increased-permeability lung edema on accuracy and sensitivity of ATV and PBF, two models of lung edema were induced by intravenous infusion of a Dextran 70 solution and alloxan monohydrate, respectively. Dogs were hyperventilated for 3 min by using a wide range of minute ventilation (VE) to produce two steady-state conditions of airway temperature. Higher levels of VE increased an estimated amount of ATV. The ATV produced by hyperventilation at VE values of 559, 158, and 72 ml.min-1.kg-1 was consistent with the gravimetric total lung mass, the blood-free wet lung weight, and the extravascular lung water volume, respectively. The coefficient of lung thermal conductivity, a practical index of the rate of heat conduction through tissue from lung vessels, was related to the ratio of the decrease in expired air temperature to VE, and estimated PBF was consistent with the thermodilution cardiac output. Pleural effusion had little effect on measurements of ATV and PBF. However, ATV and PBF showed increased variation in dogs with dextran-induced lung edema.     

Contrast mapping and evaluation for electronic X-ray images on CRT display monitor

Simple chest X rays on film are the most common type of image in medical diagnosis. However, amongst the various types of medical X-ray images, they require the highest level of display quality due to the fact that the body structures they capture on film have varying degrees of permeability to X rays. Conventional high-definition digital display technology has not always been able to match the quality of such film images. This has been a major impediment against progress toward the complete digitization of simple chest X rays. The intent of this paper is to examine that, when applied to medical diagnosis of chest X rays, super-high-definition (SHD) images (digital images with resolution exceeding that of HDTV) are capable of producing a level of quality of diagnostic accuracy on a par with conventional film images. We will start out by seeking out the overall transmission characteristics of a system that uses digital radiography and a film digitizer to digitize images. We will then derive gray-scale transform characteristics based on the luminance linear method for approximating, as closely as possible on a CRT, film images on a light box that have wide dynamic range and high luminance. Finally, we will present the results of image evaluation experiments using high-definition CRT monitors. These results indicate that conventional film images and those on super-high-definition CRT monitors have nearly the same quality. They will also show that the contrast mapping selected by radiologists and theoretical luminance linear characteristics were almost the same except in low-luminance regions. We will also discuss radiologists' comments on CRT monitors after they participated in the evaluation experiment.     

Unexpected correlation in the sensitivity of 19 herpes simplex virus strains to types I and II interferons

We compared the sensitivity of 19 herpes simplex virus (HSV) strains to type I (IFN-alpha and IFN-beta) and type II (IFN-gamma) human interferons in cultures of human retinal epithelial (K-1034) and lung (HEL) cells. Their sensitivities proved to be well correlated, even though type I and type II IFN have been reported to have different antiviral actions. The correlation was not because IFN-gamma stimulated the formation of IFN-beta, for an antibody that neutralized IFN-beta did not reduce its inhibitory effects. Our results show that each HSV strain has a characteristic and similar sensitivity to type I and type II IFN and suggest some common pathway in the mechanism of their antiviral actions.     

Nitroarene concentrations and direct-acting mutagenicity of diesel exhaust particulates fractionated by silica-gel column chromatography

Diesel exhaust particulates were extracted with benzene-ethanol (3:1, v/v) and separated into five fractions by silica-gel column chromatography. Direct-acting mutagenic activity was assayed by the Ames test using the Salmonella typhimurium YG1024 strain. The total activity of five fractions was about four times greater than that of the crude extract, suggesting that the activities in the fractions were suppressed in the crude extract. Strong activity was observed in fraction 4 which was eluted with dichloromethane (61.5% of the total activity) and fraction 5 which was eluted with ethanol (35.3%). Nitropolycyclic aromatic hydrocarbons (NPAHs) were determined by high-performance liquid chromatography with chemiluminescence detection. They were found mainly in fraction 4, although one NPAH was in fraction 3 which was eluted with n-hexane-dichloromethane (3:1, v/v). Based on these results, 53.1% of the activity in fraction 4 was attributed to NPAHs. The contribution of 1-nitropyrene and 1,3-, 1,6- and 1,8-dinitropyrenes was great and that of the other NPAHs was small. The mutagenic compound in fraction 5 was not identified. Fractions 1 and 2, which were eluted with n-hexane, and fraction 3 suppressed the activity of fraction 4. Polycyclic aromatic hydrocarbons in fractions 2 and 3 were considered as possible suppressors of NPAHs.     

Stereospecific analysis of triacyl-sn-glycerols by chiral high-performance liquid chromatography

A method for the stereospecific analysis of triacyl-sn-glycerols by high-performance liquid chromatography (HPLC) on a chiral column is described. Triacyl-sn-glycerols were partially degraded with ethyl magnesium bromide, and the monoacylglycerols produced were separated as 1- and 2-monoacylglycerol fractions by thin-layer chromatography on boric acid-impregnated silica gel plates. The 1-monoacylglycerols were resolved intosn-1 andsn-3 monoacylglycerol fractions by HPLC on a chiral column (Sumichiral OA-4100) after derivatization with 3,5-dinitrophenyl isocyanate. Fatty acid methyl esters obtained from the original triacyl-sn-glycerols, 1- and 2-monoacylglycerol fractions, andsn-1 andsn-3 monoacylglycerol fractions were analyzed by gas chromatography on open-tubular columns. Stereospecific acyl distributions in triacyl-sn-glycerols were calculated from the data. The acyl distributions of several oils were obtained. The method is rapid, simple and gave reproducible results.