Electrospray Film Deposition for Solvent-Elimination Infrared Spectroscopy

The application of electrospray (ES) for quantitative transfer of analytes from solution to an internal reflection element for analysis by attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy has been developed in this work. The ES ATR FT-IR method is evaluated with non-volatile and semi-volatile organic and inorganic compounds dissolved in pure organic solvents or organics in a mixture with water. The technique demonstrates the capability for rapid solvent evaporation from dilute solutions, facilitating the creation of thin films that allow ATR FT-IR to generate transmission-mode-like spectra. Electrospray ATR FT-IR with multiple reflections displays a linear response ( R² = 0.95-0.99) in absorbance with the deposited mass and instrumental detection limit < 100 ng, which demonstrates potential for quantitative applications. The method is applicable when crystalline substances are present, even though the formation of particles restricts the upper limit of mass loadings relative to substances forming homogeneous films. In addition to the solvent, semi-volatile compounds can evaporate during the ES process; the magnitude of losses will depend on solution composition and temperature.

Long-Term Strategy for Assessing Carbonaceous Particulate Matter Concentrations from Multiple Fourier Transform Infrared (FT-IR) Instruments: Influence of Spectral Dissimilarities on Multivariate Calibration Performance

Matching the spectral response between multiple spectrometers is a mandatory procedure when developing robust calibrations whose prediction is independent of instrument-related signal variations. A viable alternative to complex calibration transfer methods consists of matching the instrument spectral response by controlling a set of key instrumental and environmental parameters. This paper discusses the applicability of such an approach to three Fourier transform infrared (FT-IR) spectrometers used for the routine assessment of carbonaceous particulate matter concentrations in the Interagency Monitoring of PROtected Visual Environments (IMPROVE) speciation network. The effectiveness of the proposed matching procedure is evaluated by comparing the spectral response for each individual instrument in order to characterize the extent, and nature, of the remaining inter-instrument spectral dissimilarities. Instrument-related contributions to the signal were determined to be small compared with the spectral variability induced by the filter type used for sample collection. The impact of spectral differences on prediction was addressed through the comparison of model performance derived from multiple calibration scenarios. A hybrid model yielding accurate and homogeneous prediction regardless of the instrument was proposed for organic carbon (OC) and elemental carbon (EC), two major constituents of atmospheric particulate matter. Coefficients of determination of 0.98 (OC) and 0.90 (EC) with median biases not exceeding 0.20 µg (OC) and 0.07 µg (EC) are reported. The long-term stability, assessed from weekly measurements of reference samples, shows a deviation in predicted concentrations of less than ±5% over a 2.5-year period for most of the data collected. Extending OC and EC hybrid models to the prediction of ambient samples collected during the two subsequent years provides satisfactory performance. The proposed instrument matching procedure coupled with the relative simplicity of the hybrid model is an alternative to computationally advanced calibration transfer methodologies for the characterization of carbonaceous particulate matter using multiple FT-IR instruments.

Regional Similarities and NOx-related Increases in Biogenic Secondary Organic Aerosol in Summertime Southeastern U.S

During the 2013 Southern Oxidant and Aerosol Study, Fourier Transform Infrared Spectroscopy (FTIR) and Aerosol Mass Spectrometer (AMS) measurements of submicron mass were collected at Look Rock (LRK), Tennessee, and Centreville (CTR), Alabama. Carbon monoxide and submicron sulfate and organic mass concentrations were 15-60% higher at CTR than at LRK but their time series had moderate correlations (r~0.5). However, NOx had no correlation (r=0.08) between the two sites with nighttime-to-early-morning peaks 3~10 times higher at CTR than at LRK. Organic mass (OM) sources identified by FTIR Positive Matrix Factorization (PMF) had three very similar factors at both sites: Fossil Fuel Combustion (FFC) related organic aerosols, Mixed Organic Aerosols (MOA), and Biogenic Organic Aerosols (BOA). The BOA spectrum from FTIR is similar (cosine similarity > 0.6) to that of lab-generated particle mass from the photochemical oxidation of both isoprene and monoterpenes under high NOx conditions from chamber experiments. The BOA mass fraction was highest during the night at CTR but in the afternoon at LRK. AMS PMF resulted in two similar pairs of factors at both sites and a third nighttime NOx-related factor (33% of OM) at CTR but a daytime nitrate-related factor (28% of OM) at LRK. NOx was correlated with BOA and LO-OOA for NOx concentrations higher than 1 ppb at both sites, producing 0.5 ± 0.1 μg m-3 for CTR-LO-OOA and 1.0 ± 0.3 μg m-3 for CTR-BOA above 1 ppb additional biogenic OM for each 1 ppb increase of NOx.

Molecular Structure Inhibiting Synergism in Charged Surfactant Mixtures: An Atomistic Molecular Dynamics Simulation Study

Synergistic and nonsynergistic surfactant-water mixtures of sodium dodecyl sulfate (SDS), lauryl betaine (C12B), and cocoamidopropyl betaine (CAPB) systems are studied using molecular simulation to understand the role of interactions among headgroups, tailgroups, and water on structural and thermodynamic properties at the air-water interface. SDS is an anionic surfactant, while C12B and CAPB are zwitterionic; CAPB differs from C12B by an amide group in the tail. While the lowest surface tensions at high surface concentrations in the SDS-C12B synergistic system could not be reproduced by simulation, estimated partitioning between surface and bulk shows trends consistent with synergism. Structural analysis shows the influence of the SDS headgroup pulling C12B to the surface, resulting in closely packed structures compared to their respective homomolecular-surfactant systems. The SDS-CAPB system, on the other hand, is nonsynergistic when the surfactants are mixed on account of the tilted structure of the CAPB tail. The translational excess entropy due to the tailgroup interactions discriminates between the synergistic and nonsynergistic systems. The implications of such interactions on surfactant effects in complex, multicomponent atmospheric aerosols are discussed.

Aerosol Health Effects from Molecular to Global Scales

Poor air quality is globally the largest environmental health risk. Epidemiological studies have uncovered clear relationships of gaseous pollutants and particulate matter (PM) with adverse health outcomes, including mortality by cardiovascular and respiratory diseases. Studies of health impacts by aerosols are highly multidisciplinary with a broad range of scales in space and time. We assess recent advances and future challenges regarding aerosol effects on health from molecular to global scales through epidemiological studies, field measurements, health-related properties of PM, and multiphase interactions of oxidants and PM upon respiratory deposition. Global modeling combined with epidemiological exposure-response functions indicates that ambient air pollution causes more than four million premature deaths per year. Epidemiological studies usually refer to PM mass concentrations, but some health effects may relate to specific constituents such as bioaerosols, polycyclic aromatic compounds, and transition metals. Various analytical techniques and cellular and molecular assays are applied to assess the redox activity of PM and the formation of reactive oxygen species. Multiphase chemical interactions of lung antioxidants with atmospheric pollutants are crucial to the mechanistic and molecular understanding of oxidative stress upon respiratory deposition. The role of distinct PM components in health impacts and mortality needs to be clarified by integrated research on various spatiotemporal scales for better evaluation and mitigation of aerosol effects on public health in the Anthropocene.

In vitro activation of the corticosteroid ciclesonide in animal nasal mucosal homogenates

Ciclesonide, a new corticosteroid for allergic rhinitis, is administered as an inactive parent compound that is converted by esterases to the pharmacologically active metabolite, desisobutyryl-ciclesonide (des-CIC). This study investigated the in vitro activation of ciclesonide in nasal mucosa of multiple animal species. Nasal mucosal homogenates from rats, guinea-pigs, rabbits and dogs were incubated with ciclesonide 0.5 micromol/l (0.271 microg/ml) or 5 micromol/l (2.71 microg/ml) for up to 120 min. Concentrations of ciclesonide and des-CIC were measured by high-performance liquid chromatography with tandem mass spectrometry. Ciclesonide was metabolized to des-CIC in nasal mucosal homogenates of each species. The initial velocities of des-CIC formation ranged from 0.0038 to 0.0150 nmol/min/mg protein and 0.0319 to 0.0983 nmol/min/mg protein in nasal mucosal homogenates incubated with ciclesonide 0.5 micromol/l and 5 micromol/l, respectively. Furthermore, the initial velocities of ciclesonide metabolism ranged from 0.0032 to 0.0142 nmol/min/mg protein and 0.0445 to 0.1316 nmol/min/mg protein in nasal mucosal homogenates incubated with ciclesonide 0.5 micromol/l and 5 micromol/l, respectively. This study confirms that ciclesonide is converted to des-CIC in nasal mucosal homogenates without any marked differences among animal species.

Efflorescence transitions of ammonium sulfate particles coated with secondary organic aerosol

Ammonium sulfate particles were generated by atomization and introduced into a smog chamber where they were coated with secondary organic aerosol from ozonolysis of limonene or alpha-pinene. These mixed particles were then sampled with a humidified Tandem-DMA system where a monodisperse aerosol population was selected, humidified, and dried to observe the relative humidity (RH) at which the particles returned to the original dry diameter. The volume fraction of secondary organic aerosol (SOA) in the mixed particles ranged from 0.59 to 0.94 for limonene SOA and 0.54 to 0.72 for alpha-pinene SOA. Efflorescence RHs for our mixed aerosols were in the range of 28-34%, similar to our observation of 32% ERH for pure ammonium sulfate nanoparticles. These findings indicate that the effect of SOA on the ERH of inorganic salts in the atmosphere may be negligible.

Semicontinuous measurements of organic carbon and acidity during the Pittsburgh Air Quality Study: implications for acid-catalyzed organic aerosol formation

Laboratory evidence suggests that inorganic acid seed particles may increase secondary organic aerosol yields secondary organic aerosol (SOA) through heterogeneous chemistry. Additional laboratory studies, however, report that organic acidity generated in the same photochemical process by which SOA is formed may be sufficient to catalyze these heterogeneous reactions. Understanding the interaction between inorganic acidity and SOA mass is important when evaluating emission controls to meet PM2.5 regulations. We examine semicontinuous measurements of organic carbon (OC), elemental carbon (EC), and inorganic species from the Pittsburgh Air Quality Study to determine if we can detect coupling in the variations of inorganic acidity and OC. We were not able to detect significant enhancements of SOA production due to inorganic acidity in Western Pennsylvania most of the time, but its signal might have been lost in the noise. If we assume a causal relationship between inorganic acidity and OC, reductions in OC for Western Pennsylvania that might result from drastic reductions in inorganic acidity were estimated to be 2 +/- 4% by a regression technique, and an upper bound for this geographic area was estimated to be 5 +/- 8% based on calculations from laboratory measurements.

Two interactive genes responsible for a new inherited cataract (RCT) in the mouse

We discovered a mutant mouse, RCT (Rinshoken cataract), with a new congenital cataract in strain SJL/J. The opacity of the lens associated with microphthalmia could be observed visually at 3 to 3.5 months of age. Marked degeneration of the lens, including loss of the fine structure of the lens fibers and swelling of epithelial cells with vacuoles of various sizes in the cortex, but no other defects except photoreceptor degeneration in the retina, was detected. Histological change in the lens was first observed at 2 days after birth. No sex-related differences were detected, and normal phenotypes in the F1 progeny of RCT and normal mice indicated that the cataract was recessive. The chromosomal location of the causative gene was determined by interval mapping by using intersubspecific backcross progeny of RCT and MSM/Ms, an inbred strain from the Japanese wild mouse Mus musculus molossinus. Backcross progeny were divided into three groups according to phenotype: mice (1) with an early-onset cataract, which can be detected visually as in RCT mice, (2) with a late-onset cataract, which can be detected histologically but not visually, and (3) with a normal lens. Three phenotypes were found to be expressed by allele combinations of two recessive genes, rct and mrct (a modifier of rct). The rct locus essential for the onset of the cataract was tightly linked to D4Mit278 on Chromosome (Chr) 4 with no recombination. The mrct locus was closely linked to D5Mit239 (chi2 = 66.3, P << 0.00001) on Chr 5.

[Deficits of Morris water maze learning in rats with striatal kainic acid lesions]

This study investigated effects of intrastriatal kainic acid administration, which induces selective neuronal cell death in the striatum sparing passing nerve fibers and terminals, on the acquisition of spatial learning in Morris water maze. Rats treated with bilateral kainic acid (0.5-1.0 microgram) into the striatum were trained to escape to a hidden platform under the water. Compared with control rats, kainic acid (1.0 microgram)-lesioned rats showed significantly longer escape latency in the place navigation, and in the following probe test lower rate of swimming within the quadrant where the platform had been placed. In addition, kainic acid (1.0 microgram)-lesioned rats showed longer latency in the cue navigation in which rats were trained to escape to a visible platform above the water. These deficits were caused by their tendency to swim along the wall of pool before approaching the platform and not by their swim difficulty. Results suggest that striatal neurons or neural circuits containing these neurons play an important role in the acquisition of spatial learning task, and the nature of this performance impairment was discussed in terms of both learning and attention deficits.

Maternal inheritance of mouse mtDNA in interspecific hybrids: segregation of the leaked paternal mtDNA followed by the prevention of subsequent paternal leakage

The transmission profiles of sperm mtDNA introduced into fertilized eggs were examined in detail in F1 hybrids of mouse interspecific crosses by addressing three aspects. The first is whether the leaked paternal mtDNA in fertilized eggs produced by interspecific crosses was distributed stably to all tissues after the eggs' development to adults. The second is whether the leaked paternal mtDNA was transmitted to the subsequent generations. The third is whether paternal mtDNA continuously leaks in subsequent backcrosses. For identification of the leaked paternal mtDNA, we prepared total DNA samples directly from tissues or embryos and used PCR techniques that can detect a few molecules of paternal mtDNA even in the presence of 10(8)-fold excess of maternal mtDNA. The results showed that the leaked paternal mtDNA was not distributed to all tissues in the F1 hybrids or transmitted to the following generations through the female germ line. Moreover, the paternal mtDNA leakage was limited to the first generation of an interspecific cross and did not occur in progeny from subsequent backcrosses. These observations suggest that species-specific exclusion of sperm mtDNA in mammalian fertilized eggs is extremely stringent, ensuring strictly maternal inheritance of mtDNA.

Four dominant loci for the vascular responses by the antitumor polysaccharide, lentinan

Lentinan, beta-1,6;1,3-glucan, showing an antitumor effect against mouse solid type tumors, can induce marked vascular dilation and hemorrhage (VDH) in very localized areas such as the ears, feet, and tails of mice in the early stages after its administration (Maeda et al. 1984). VDH has been found to be one of the T-cell-mediated responses triggered by lentinan. We reported previously that the responsiveness of mice to lentinan with respect to VDH induction is controlled by a dominant gene(s), Ltn2 (formerly), and that no sex difference was observed (Maeda et al. 1991). To determine the chromosomal location of the Ltn2 gene(s), we typed genomic DNAs of 193 N2 segregants of crosses between a high responder MA/MyJ and a low responder AKR/J by the polymerase chain reaction-simple sequence length polymorphism technique using 83 chromosome-specific microsatellite markers. We identified one major gene (Ltnr3) and three minor genes (Ltnr4, Ltnr5, and Ltnr6) responsible for the VDH induction. Ltnr3 was closely linked to D6Mit135 on chromosome 6 (P <0.00000) and Ltnr4, Ltnr5, and Ltnr6 to D9Mit161 on chromosome 9 (P <0.00032), D15Mit147 on chromosome 15 (P <0.00014) and D16Mit4 on chromosome 16 (P <0.00014), respectively.

Polygenic control of the expression of biological activities of an antitumor polysaccharide, lentinan

Genetic studies were carried out on two in vivo responses of lentinan, delayed type-acute phase responses (DT-APR) and vascular dilation and hemorrhage (VDH). Linkage analyses showed that DT-APR was controlled by two recessive genes, ltnr1 and ltnr2, which were mapped on chromosome 3 and 11, respectively. VDH was also found to be controlled by polygenes. One dominant major gene, Ltnr3, and three dominant minor genes, Ltnr4, Ltnr5, and Ltnr6, were mapped on chromosomes 6, 9, 15 and 16, respectively.

Two genes controlling acute phase responses by the antitumor polysacch aride, lentinan

Lentinan, a beta-1,6;1,3-glucan, is tumor-specific for transplantable mouse solid-type tumors and it also stimulates the production of acute phase proteins (APPs). The APP response to lentinan is of the delayed type (DT-APR) and differs from that to lipopolysaccharide, which is acute. We found that the responses were genetically controlled in mice and that low responsiveness is dominant (Maeda et al. 1991). Using 123 segregants of crosses between SWR/J (a high responder) and Mus spretus (a low responder), we analyzed the linkage between DT-APR responsiveness and the DNA polymerase chain reaction-simple sequence length polymorphism (PCR-SSLP) phenotype using 80 chromosome-specific microsatellite markers. We identified two loci (ltn1.1 and ltn1.2) responsible for DT-APR. ltn1.1 is closely linked to D3Mit11 on chromosome 3 and ltn1.2 to D11Nds9 on chromosome 11 (P <0.001). The linkage analysis also suggested that ltn1.2 is the major determinant for DT-APR. Correlation between lentinan-specific IL-6 mRNA expression (the late expression) controlled recessively and DT-APR induction suggests that the ltn1 loci control some process(es) of IL-6 expression in the regulation step before NF-IL6.

The effect of pH, hydrogen peroxide and temperature on the stability of human monoclonal antibody

The stability of human monoclonal antibody (C23), which is being developed as a passive immunotherapeutic agent against human cytomegalovirus, was investigated. C23 (about 2 mg ml-1) was incubated under sterile conditions for 14 days in buffers with different pH values (ranging from 4-10), in hydrogen peroxide solutions with different concentrations (0.01% or 0.1%), and in saline at 8 degrees C or 37 degrees C. Samples were collected on days 0, 3, 7 and 14, and various physicochemical or biological methods were used to determine the changes in in C23. These methods included turbidity (absorbance at 408 nm and transmittance at 580 nm), pH, size-exclusion high performance liquid chromatography (HPLC), hydroxyapatite HPLC, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing, matrix-assisted laser desorption ionization time-of-flight mass spectrometry and virus neutralization assay. Using these methods, the possible degradation processes of C23 were initially characterized. Deamidation, oxidation, fragmentation, covalent cross-links and aggregation were observed as major degradation routes. These results gave useful information for the manufacturing process and quality control of C23.

Elimination of paternal mitochondrial DNA in intraspecific crosses during early mouse embryogenesis

To examine whether mtDNA is uni- or biparentally transmitted in mice, we developed an assay that can detect sperm mtDNA in a single mouse embryo. In intraspecific hybrids of Mus musculus, paternal mtDNA was detected only through the early pronucleus stage, and its disappearance co-incided with loss of membrane potential in sperm-derived mitochondria. By contrast, in interspecific hybrids between M. musculus and Mus spretus, paternal mtDNA was detected throughout development from pronucleus stage to neonates. We propose that oocyte cytoplasm has a species-specific mechanism that recognizes and eliminates sperm mitochondria and mtDNA. This mechanism must recognize nuclearly encoded proteins in the sperm midpiece, and not the mtDNA or the proteins it encodes, because sperm mitochondria from the congenic strain B6.mtspr, which carries M. spretus mtDNA on background of M. musculus (B6) nuclear genes, were eliminated early by B6 oocytes as in intraspecific crosses. We conclude that cytoplasmic genomes are transmitted uniparentally in intraspecific crosses in mammals as in Chlamydomonas and that leakage of parental mtDNA is limited to interspecific crosses, which rarely occur in nature.

[Efficacy of smoking cessation instruction for general smokers at an annual physical examination]

A randomized controlled trial was conducted to evaluate the efficacy of smoking cessation instruction given to general smokers at an annual physical examination. Four hundred and twenty-six male and 42 female clients were randomly assigned to an intervention group (I), and 413 males and 76 females were assigned to a control (C) group. The I group was given an approximately 2-minute smoking cessation instruction by physicians, answered a quiz concerning tobacco, chose their own behavioral goals and were handed a leaflet on how to quit smoking. Subjects in both groups responded to a self-administered questionnaire and a 6-month and 12-month follow-up was performed by post card or telephone. The I group received an encouragement card one month after instruction and abstainers of the I group were awarded a telephone card at the 6-month follow-up. The results were as follows: 1) The male I group exhibited 7.3% (6 months), 10.1% (12 months) abstinence rates and the male C group 4.4% (6 months), 5.3% (12 months), respectively. The difference in 12-month abstinence rates was statistically significant. 2) The female I group exhibited abstinence rates of 16.7% (6 months), 23.8% (12 months) and the female C group 14.5% (6 months), 17.1% (12 months), respectively. 3) A multivariate analysis of smoking cessation showed that lower nicotine dependency, strong determination for smoking cessation, and being female were significant factors for abstinence at the 6-month follow-up. At 12 months, the smoking cessation instruction also became a significant factor. These data suggest that a simple smoking cessation instruction at an annual physical examination was effective for general smokers.

Inhibitory effects of prostacyclin analogue, TFC-132, on aortic neointimal thickening in vivo and smooth muscle cell proliferation in vitro

Effects of a new prostacyclin analogue, TFC-132, on neointimal thickening following intimal mechanical injury and on the proliferation of cultured aortic smooth muscle cells (SMCs) were studied. The intimal injury was induced by indwelling of polyethylene tubing for 24 h in the rabbit aorta. Rabbits were killed 10 days after drawing out the tubing. TFC-132 (0.6 mg/kg or 1.2 mg/kg) was given orally at 8-h intervals through the experiment. The serum concentrations of the analogue rose significantly 1 and 2 h after administration. The mean intimal thickening in the TFC-132 treated groups was significantly thinner than in the control one. Human aortic SMCs were cultured and 3H-thymidine incorporation into DNA (DNA synthesis) was measured at the varying concentrations of TFC-132. The analogue inhibited DNA synthesis of cultured SMCs at 10(-6) and 10(-5) M. These data indicate that a new prostacyclin analogue, TFC-132, has an inhibitory effect on the neointimal thickening after intimal injury and on the aortic SMC proliferation.

Platinum/carbon multilayer reflectors for soft-x-ray optics

We have fabricated platinum/carbon (Pt/C) multilayer reflectors with 2d spacaings between 50 and 200 Å, using an electron-beam evaporator. We investigated the effects of 2d values, the number of layer pairs, substrate temperature, coatings, and the long-term stability on the reflectivity performance by using characteristic x rays and monochromatized synchrotron radiation in the 0.8-8-keV region. In this study we show that Pt/C multilayers with 10-20 layer pairs exhibit high and stable soft-x-ray reflectivity. The interfacial roughness was measured in the range of 5 Å and becomes lower for structures deposited at liquid-nitrogen temperatures. Coating these reflectors with a 100-Å-thick platinum layer increased the grazing angle reflectivity without significantly lowering the Bragg peak reflectivity.

Development of radioimmunoassay for TG-51, a new anti-ulcer drug, and its application

A sensitive and specific radioimmunoassay for a new anti-ulcer drug TG-51 has been developed and applied to the evaluation of its pharmacokinetics in humans. The antiserum was raised in rabbits against an immunogen of N-Acetyl-TG-51 coupled to human serum albumin. The radioactive compound was prepared by acetylating TG-51 with 3H-Acetic anhydride. The separation of free and antibody-bound N-Acetyl-TG-51 was performed by the dextran coated charcoal technique. TG-51 in biological fluids could be quantitatively converted to N-Acetyl-TG-51 prior to radioimmunoassay. This assay system made it possible to ascertain values of 3 ng/ml of TG-51 in plasma using 100 microliters of samples. Results were in good agreement with a high performance liquid chromatography method (HPLC), and the detection limit was raised 25 fold. The accuracy and repoducibility were also satisfactory. By use of this assay method, plasma levels of TG-51 could be determined after a single oral administration of clinical doses of human volunteers.

Quantification of 5-fluoro-2'-deoxyuridine in plasma by gas chromatography and negative-ion chemical ionization mass spectrometry

A sensitive and specific method using gas chromatography and negative-ion chemical ionization mass spectrometry is described for the determination of 5-fluoro-2'-deoxyuridine (FdUrd) in plasma. The method is based on the formation of the pentafluoropropionyl derivative of FdUrd and of its stable isotope as internal standard after sample clean-up by solid-phase extraction and purification by high-performance liquid chromatography. Quantification in plasma was possible down to 300 pg/ml. The method was applied to the analysis of plasma levels of FdUrd in mice and dogs.

Detection of myocardial infarction in the presence of Wolff-Parkinson-White syndrome by QRST isoarea map in dogs

The possibility of detecting myocardial infarction (MI) in the presence of Wolff-Parkinson-White (WPW) syndrome by means of body surface QRST isoarea maps was studied in eight dogs. Eighty-seven body surface ECGs were recorded simultaneously. Recordings were taken during right atrial (RA) and right atrial and right ventricular (RA + RV) sequential pacing, which simulated WPW syndrome, during control periods and at 1-hour intervals for up to 5 hours after occlusion of the left anterior descending coronary artery. In ECGs during the RA drive, diagnostic findings of MI such as abnormal Q waves were observed but became obscure during the RA + RV drive. On the contrary, the QRST values over the anterior chest during both drives were positive soon after coronary occlusion, decreased gradually as time passed, and became abnormally negative after 5 hours. The QRST isoarea maps during RA and RA + RV pacing showed quite similar patterns and were highly correlated with each other throughout this study (r greater than 0.95). These findings demonstrate that localized abnormalities resulting from MI are evident in QRST isoarea maps even in the presence of preexcitation and fusion.

Effect of a new anti-ulcer drug, (3-[p-(trans-4-aminomethylcyclohexylcarbonyl)-phenyl] propionic acid hydrochloride, TEI-5103) on prostaglandin (PG) levels in rat gastric mucosa

1. Effect of TEI-5103 on the levels of various prostaglandins (PG's) in rat gastric mucosa was studied by HPLC and RIA methods. 2. When administrated in vivo, TEI-5103 significantly increased the level of prostaglandin E2 (PGE2) but only slightly increased that of prostaglandin I2 (PGI2) or thromboxane A2 (TXA2). 3. In the water-immersion stress model, the PGE2 level in control animals was increased immediately after stress and then decreased gradually to the initial level. Indomethacin (5 mg/kg, s.c.) sustained a lower PGE2 level during the experiment, as well as aggravated the lesions. 4. TEI-5103 (400 mg/kg, p.o.) increased the PGE2 level just before stress, and it resulted in the prevention of lesion formation. 5. TEI-5103 inhibited the activity of 15-OH-PG-dehydrogenase from guinea pig lungs, but did not affect the activity of phospholipase A2 from porcine pancreas.