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The broad absorption of Cl3 radical was observed between 1150 and 1350 nm using cavity ring-down spectroscopy at 213-265 K and 50-200 Torr with He, N2, Ar, or SF6 diluents. The absorption intensity of Cl3 increased at lower temperature and higher pressure. SF6 was the most efficient diluent gas. The temperature dependent equilibrium constants for Cl3 formation from Cl+Cl2 were theoretically calculated at the MP4SDQ6-311+G(d) level. Observed decay time profiles of Cl3 and the pressure dependence of Cl3 formation are explained by the equilibrium reaction and a decay reaction of Cl+Cl3.

The reactions of iodine monoxide radical, IO, with alkyl peroxide radicals, RO(2) (R = CH(3), C(2)H(5), and CF(3)), have been studied using cavity ring-down spectroscopy. The rate constant of the reaction of IO with CH(3)O(2) was determined to be (7.0 +/- 3.0) x 10(-11) cm(3) molecule(-1) s(-1) at 298 K and 100 Torr of N(2) diluent. The quoted uncertainty is two standard deviations. No significant pressure dependence of the rate constant was observed at 30-130 Torr total pressure of N(2) diluent. The temperature dependence of the rate constants was also studied at 213-298 K. The upper limit of the branching ratio of OIO radical formation from IO + CH(3)O(2) was estimated to be <0.1. The reaction rate constants of IO + C(2)H(5)O(2) and IO + CF(3)O(2) were determined to be (14 +/- 6) x 10(-11) and (6.3 +/- 2.7) x 10(-11) cm(3) molecule(-1) s(-1) at 298 K, 100 Torr of N(2) diluent, respectively. The upper limit of the reaction rate constant of IO with CH(3)I was <4 x 10(-14) cm(3) molecule(-1) s(-1).

Lipophilic toxins associated with diarrhetic shellfish poisoning (DSP) in scallops, Patinopecten yessoensis, collected in Hokkaido, Japan were quantified by liquid chromatography-mass spectrometry (LC/MS). Pectenotoxin-6 (PTX6) and yessotoxin (YTX) were the dominant toxins in the scallops, although the percentages of these toxins were different depending on the production area or the sampling period. The quantitative results obtained for the scallops in LC/MS and in mouse bioassay (MBA) were compared. Fifty of the 55 samples found to be exceeding the local quarantine level (0.025 MU/g whole meat) in Hokkaido by LC/MS were quantified by MBA as being below the quarantine level. It is suggested that this discrepancy is due to poor detection of YTX by MBA. These results indicate that LC/MS is a better method than MBA in terms of sensitivity and accuracy to quantify known lipophilic toxins, including YTX.

Cavity ring-down spectroscopy was used to study the reaction of ClOO with NO in 50-150 Torr total pressure of O2/N2 diluent at 205-243 K. A value of k(ClOO+NO) = (4.5 +/- 0.9) x 10(-11) cm3 molecule(-1) s(-1) at 213 K was determined (quoted uncertainties are two standard deviations). The yield of NO(2) in the ClOO + NO reaction was 0.18 +/- 0.02 at 213 K and 0.15 +/- 0.02 at 223 K. An upper limit of k(ClOO+Cl2) < 3.5 x 10(-14) cm3 molecule(-1) s(-1) was established at 213 K. Results are discussed with respect to the atmospheric chemistry of ClOO and other peroxy radicals.

Buffer-gas pressure broadening for the (3 0(0) 1)(III)<--(0 0 0) band of CO(2) in the 1600 nm region was investigated with continuous wave cavity ring-down spectroscopy within the temperature range 263-326 K. The measured absorption profiles were analyzed with Voigt functions. Pressure broadening coefficient, gamma(gas), and the temperature dependent parameter (broadening exponent), n, were determined for a variety of buffer gases: N(2), O(2), He, Ne, Ar, Kr and Xe. gamma(air) values estimated subsequently are 0.096(2) for R(0), 0.085(5) for P(8), 0.075(2) for P(16), 0.070(4) for P(26), and 0.069(2) for P(38) in units of cm(-1) atm(-1), where numbers in parentheses are one standard deviation in units of the last digits quoted. n(air) values are 0.77(4) for R(0), and 0.73(11) for P(8).

The reactions of Cl atoms with XCH2I (X = H, CH3, Cl, Br, I) have been studied using cavity ring-down spectroscopy in 25-125 Torr total pressure of N2 diluent at 250 K. Formation of the XCH2I-Cl adduct is the dominant channel in all reactions. The visible absorption spectrum of the XCH2I-Cl adduct was recorded at 405-632 nm. Absorption cross-sections at 435 nm are as follows (in units of 10(-18) cm2 molecule(-1)): 12 for CH3I, 21 for CH3CH2I, 3.7 for CH2ICl, 7.1 for CH2IBr, and 3.7 for CH2I2. Rate constants for the reaction of Cl with CH3I were determined from rise profiles of the CH3I-Cl adduct. k(Cl + CH3I) increases from (0.4 +/- 0.1) x 10(-11) at 25 Torr to (2.0 +/- 0.3) x 10(-11) cm3 molecule(-1) s(-1) at 125 Torr of N2 diluent. There is no discernible reaction of the CH3I-Cl adduct with 5-10 Torr of O2. Evidence for the formation of an adduct following the reaction of Cl atoms with CF3I and CH3Br was sought but not found. Absorption attributable to the formation of the XCH2I-Cl adduct following the reaction of Cl atoms with XCH2I (X = H, CH3, Br, I) was measured as a function of temperature over the range 250-320 K.

Our purpose was to investigate whether the local or systemic factors of pregnancy are associated with inducible nitric oxide synthase (iNOS) mRNA expression and to determine the inhibitory effects of pharmacological agents that increase cGMP levels in rat myometrium. iNOS mRNA expression was determined in uterine tissues from nonpregnant rats and on day 17 of gestation in the pregnant and non-pregnant uterine horns by RT-PCR. In addition, uterine rings from the pregnant and non-pregnant uterine horns were placed in Krebs-Henseleit solution for isometric recordings of spontaneous contractions. Concentration-inhibition relationships to diethylamine/nitric oxide complex, 8-bromo-cGMP, and the selective phosphodiesterase V inhibitor were obtained. Compared to nonpregnant rats, expression of iNOS mRNA in myometrium increased during pregnancy, which was maximal on day 17, followed by a decrease on day 21 of gestation. Expression of iNOS mRNA at day 17 of gestation was greater in pregnant uterine horns than in nonpregnant ones. Maximal inhibition of phosphodiesterase V and increasing cGMP induced similar inhibition of spontaneous contractions in nonpregnant and pregnant uterine horns, while NO induced less inhibition in the former. The results suggest that the local pregnancy factor is needed for signal transduction from NO to soluble guanylate cyclase at a time when maximal expression of iNOS mRNA is evident.

Remnants of cardiomyocytes showing coagulation necrosis in the scars caused by myocardial infarction were histopathologically studied. Among 305 autopsy cases of acute and/or healed myocardial infarction, 8 cases (7 men, 1 woman, ages 62 - 87 years, mean age 72.1) had masses of cardiomyocytes with coagulation necrosis at the center of the infarction scars more than 3 weeks (21 to 79 days) after the attack of myocardial infarction. All these cases had transmural infarction and more than 80% of the wall thickness of the left ventricle was involved in the infarction. No polymorphonuclear leukocytic infiltration or granulation tissue was found in the necrotic area, but macrophages were observed in the peripheral area adjacent to the scar tissue. Immunohistochemical staining for myoglobin showed no reaction in remnant necrotic cells or pericellular interstitium, which was similar to findings in the necrotic area more than 4 days after the infarction. These findings are important in the pathological diagnosis to distinguish remnant necrosis from acute necrosis, because 4 out of 8 present cases (50%) were misdiagnosed as acute myocardial infarction that superimposed on the previous old infarction.

RCAS1, a novel tumor-associated antigen, is expressed in advanced human neoplasias including uterine and ovarian carcinomas. RCAS1 protein was indicated to induce cell cycle arrest and apoptosis of cultured human lymphoid and myeloid cell lines and normal lymphocytes. In the present study, we investigated the expression and prognostic value of RCAS1 in 58 patients with colorectal carcinomas. RCAS1 protein was detected by immunoperoxidase staining using a mouse monoclonal anti-RCAS1 antibody (22-1-1 antibody). Immunohistochemical examination showed expression of RCAS1 in 75% of colorectal carcinomas with lymph node metastases (n = 24), whereas it was present in only 41% of tumors without metastases (n = 34, P <.05). Patients with RCAS1-positive tumors showed a significantly poorer prognosis than those negative for RCAS1 (P <.05). Multivariate analysis using the Cox regression model indicated that RCAS1 positivity was an independent negative predictor for survival (P =.0300; risk ratio, 0.496). In addition, apoptotic cells of tumor-infiltrating lymphocytes were examined using nonradioactive in situ nick translation in paraffin-embedded sections. The proportion of apoptotic tumor-infiltrating lymphocytes was significantly higher in RCAS1-positive colorectal carcinomas (11.2 +/- 1.0) than in RCAS1-negative tumors (7.9 +/- 1.0, P <.05). Our results suggest that overexpression of RCAS1 may negatively affect the prognosis of human colorectal carcinomas and that RCAS1 may play a role in tumor immune privilege in vivo.

Two optical methods, cavity ring-down spectroscopy and photoacoustic spectroscopy, are applied to the measurement of the isotope ratio 18O/16O in water-vapor samples with a Nd3+:YAG pumped-dye laser. The combination band of (2v1 + v3) in the 960-nm region of water molecules is investigated for two standard water samples, the Vienna Standard Mean Ocean Water and the Standard Light Antarctic Precipitation. The results demonstrate that the two methods have the potential of compact systems for in-situ measurements of H2O isotope ratio in the environment.