A-band methyl halide dissociation via electronic curve crossing as studied by electron energy loss spectroscopy.

Excitation of the A-band low-lying electronic states in the methyl halides, CH(3)I, CH(3)Br, CH(3)Cl, and CH(3)F, has been investigated for the (n-->sigma*) transitions, using electron energy loss spectroscopy (EELS) in the range of 3.5-7.5 eV. For the methyl halides, CH(3)I, CH(3)Br, and CH(3)Cl, three components of the Q complex ((3)Q(1), (3)Q(0), and (1)Q(1)) were directly observed, with the exception of methyl fluoride, in the optically forbidden EELS experimental conditions of this investigation. The effect of electronic-state curve crossing emerged in the transition probabilities for the (3)Q(0) and (1)Q(1) states, with spin-orbit splitting observed and quantified against results from recent ab initio studies.

Substitution effects in elastic electron collisions with CH3X (X=F, Cl, Br, I) molecules.

We report absolute elastic differential, integral, and momentum transfer cross sections for electron interactions with the series of molecules CH(3)X (X=F, Cl, Br, I). The incident electron energy range is 50-200 eV, while the scattered electron angular range for the differential measurements is 15 degrees-150 degrees. In all cases the absolute scale of the differential cross sections was set using the relative flow method with helium as the reference species. Substitution effects on these cross sections, as we progress along the halomethane series CH(3)F, CH(3)Cl, CH(3)Br, and CH(3)I, are investigated as a part of this study. In addition, atomic-like behavior in these scattering systems is also considered by comparing these halomethane elastic cross sections to results from other workers for the corresponding noble gases Ne, Ar, Kr, and Xe, respectively. Finally we report results for calculations of elastic differential and integral cross sections for electrons scattering from each of the CH(3)X species, within an optical potential method and assuming a screened corrected independent atom representation. The level of agreement between these calculations and our measurements was found to be quite remarkable in each case.

Clinical significance of serum CEA protein and CEA mRNA after resection of colorectal liver metastases.

BACKGROUND: It is difficult to predict the recurrence of colorectal liver metastasis after curative hepatectomy. We investigated the relationship between subsequent metastasis and both CEA protein and CEA mRNA (TaqMan PCR) diachronic levels. PATIENTS AND METHODS: The subjects were 30 patients with colorectal liver metastases. Serum CEA protein and CEA mRNA assays were performed every month after hepatectomy. RESULTS: Metastasis recurred in 21 of the 30 patients. The CEA mRNA assay showed 26 cases with high (H) levels and 4 with low (L). Among the 15 patients whose protein levels were not elevated (NE group), 6 had recurrence; all 6 belonged to the mRNA H group. None of the 4 patients in the mRNA L group had recurrence. In the protein-elevated (E) group (DFI > 6 months) (n = 7), mRNA was elevated in 5 cases (71.4%) 6 months before recurrence, whereas protein was elevated in 1 case. The sensitivity, specificity and accuracy of CEA protein/mRNA for identifying recurrence were 71.4/100, 100/44.4, and 80/83.3%, respectively. CONCLUSION: CEA mRNA is more sensitive than CEA protein in detecting recurrence. CEA mRNA may be useful for identifying high-risk groups or detecting recurrence at an early stage, when the CEA protein level is still low.

Surveillance of perioperative infections after adult living donor liver transplantation.

AIM: This study was conducted to clarify the management of perioperative infectious complications after adult living donor liver transplantation (LDLT). PATIENTS AND METHODS: Fourteen adult LDLT patients were enrolled in this study. We examined the occurrence of infectious complications in these cases and the relationships of infectious complications to UNOS status and MELD score. Surveillance culture and immunoserologic analyses were performed. From the results of these analyses, we made a diagram of infection surveillance using a matrix of time and sampling site. Using the diagram, we chose sensitive antibiotics as soon as possible. RESULTS: The infection site and its pathogen were able to be detected in four (28.5%) patients, all of whom had MRSA infections, together with lung aspergillosis in one case, pseudomonas pneumonia in another, and both in another. Two patients died of lung aspergillosis. Bacteria detected in the airway tended to spread to other sites during the postoperative period. In all four patients in whom infectious diseases were detected, and in a fifth patient in whom the site of infection was not known, the UNOS status was 1. The MELD score was calculated in eight patients, six of whom had high MELD scores (>20). CONCLUSION: Most cases were manageable by choosing and changing antibiotics and antifungal drugs according to the results of surveillance cultures twice a week. However, aspergillosis had an extremely poor prognosis. Patients with a high MELD score or low UNOS status, or both, showed poor prognosis; and in them, multiple drug resistance bacteria caused severe perioperative infectious complications.

Diminished inibitory action of ethanol on the contraction of gallbladder isolated from chronically ethanol-fed Guinea pigs.

Ethanol is known to decrease the gallbladder contractility. The purpose of this study was to clarify the mechanism of tolerance to the inhibitory action of ethanol on the gallbladder contractility. Male guinea pigs were fed ethanol (3%) or calorie-matched sucrose in the drinking water for 4 weeks. Then, the gallbladder was isolated, and its isometric tension was measured. The contractile responses to KCl, BAY K8644, histamine, and phorbol 12,13-dibutyrate in the normal medium were not different between the gallbladder strips from ethanol-fed and control guinea pigs. Ethanol at 25 mmol/l in vitro did not affect the contractile responses to KCl and BAY K8644 in the gallbladder strips from both ethanol-fed and control guinea pigs. On the other hand, ethanol at 25 mmol/l in vitro significantly inhibited the contractile responses to histamine and phorbol 12,13-dibutyrate in the gallbladder strips from the control guinea pigs, but it did not affect the contractile response to histamine and significantly augmented that to phorbol 12,13-dibutyrate in the strips from the ethanol-fed guinea pigs. Diphenhydramine, a selective H(1) receptor antagonist, abolished the histamine contraction in gallbladder strips from both control and ethanol-fed guinea pigs, while cimetidine, a selective H(2) receptor antagonist, did not affect histamine contraction, implying that histamine-induced contraction of guinea pig gallbladders is mediated only by H(1) receptors. Verapamil (1 micromol/l) completely inhibited the phorbol 12,13-dibutyrate-induced contraction of the strips from both ethanol-fed and control guinea pigs. The histamine-induced contraction was partly inhibited in the absence of Ca(2+) in the medium. In the gallbladder strips from both ethanol-fed and control guinea pigs, ethanol at 25 mmol/ in vitro did not affect the histamine-induced contraction in the absence of extracellular Ca(2+). Tolerance to the inhibitory action of ethanol developed selectively on contractile responses to histamine and phorbol 12,13-dibutyrate. Chronic ethanol administration produces tolerance to in vitro gallbladder contractility mediated by the Ca(2+) entry through L-type Ca(2+) channels linked with protein kinase C activation.

Acidosis inhibits gallbladder contraction mediated by protein kinase C activation.

The effects of extracellular acidosis on gallbladder contraction were investigated using gallbladder strips isolated from guinea pigs. In an acidic medium (pH 6.9), gallbladder contraction induced by histamine and prostaglandin E2 was significantly lower than that in a normal medium (pH 7.4). Acidosis affected neither gallbladder contraction induced by histamine in the absence of extracellular Ca2+ nor that induced by KCl. Acidosis significantly inhibited Ca2+-induced contraction in the presence of sodium fluoride and phorbol 12,13-dibutyrate but not that in the presence of KCl. Staurosporine (30 nM) significantly inhibited gallbladder contraction induced by histamine and prostaglandin E2, but not that by KCl. Histamine-induced contraction in the presence of staurosporine was not affected by acidosis. Acidosis significantly inhibited Ca2+-induced contraction in the presence of histamine but not that in the presence of both histamine and staurosporine. These results suggest that extracellular acidosis selectively inhibits gallbladder contraction mediated by protein kinase C activation.

Intracellular alkalinization augments alpha(1)-adrenoceptor-mediated vasoconstriction by promotion of Ca(2+) entry through the non-L-type Ca(2+) channels.

Modulation by intracellular pH of the vasoconstriction induced by alpha-adrenoceptor agonists was investigated in isolated guinea pig aorta. NH(4)Cl (15 mM) increased intracellular pH of aortic smooth muscle cells by about 0.2 pH unit and significantly augmented KCl-induced contraction of aortic strips, whereas simultaneous administration of NH(4)Cl (15 mM) plus Na(+) propionate (30 mM) failed to affect intracellular pH or contractility. NH(4)Cl (15 mM) potentiated contractions induced by alpha-adrenoceptor agonists, norepinephrine, phenylephrine and clonidine. Contraction induced by alpha(1)-selective adrenoceptor agonist, phenylephrine, but not that induced by norepinephrine or clonidine, was insensitive to inhibition by verapamil (1 microM). Phenylephrine-induced contraction was not affected by NH(4)Cl in Ca(2+)-free medium whereas extracellular Ca(2+)-induced contraction of phenylephrine-stimulated aorta was significantly augmented by NH(4)Cl. Consistently, 45Ca(2+)uptake into phenylephrine 1 microM)-stimulated aortic strips was increased by incubation with NH(4)Cl. The potentiating effects of NH(4)Cl on both phenylephrine-induced Ca(2+) entry and contraction were antagonized by Na(+) propionate. These results suggest that intracellular alkalinization facilitates alpha(1)-adrenoceptor-mediated vasoconstriction by facilitation of an agonist-induced Ca(2+) entry pathway that is independent of L-type Ca(2+) channels.

Analysis of microcystins in sediments using MMPB method.

During the course of study on the detoxification of microcystins, the adsorption on sediments in the natural environment was investigated. Because it was very difficult to extract microcystins from sediments using conventional techniques, a physicochemical screening method, the MMPB (2-methyl-3-methoxy-4-phenylbutyric acid) method, including ozonolysis and mass spectrometric detection was developed. This method consisted of the following operations: lyophilized sediments were suspended in methanol and MMPB-d(3) as an internal standard was added to this suspension, which was cooled at -78 degrees C with vigorous stirring and then treated with a stream of ozone/oxygen. After centrifugation, an aliquot of the reaction solution was subjected to EI (electron ionization)-GC/MS analysis after methylation with 14% BF(3)-methanol and liquid-liquid extraction. The established method had a potential for the analysis of microcystins in sediments that are difficult to analyze using conventional methods. Finally, this method was applied to sediment samples collected in Japanese lakes and six of the eleven samples showed positive results. The obtained results clearly indicated that the adsorption on sediments contributes to the detoxification of microcystins under natural conditions.

One- and two-dimensional 15N exchange CP/MAS NMR studies of the structure and electronic properties of the intermolecular N-H...N hydrogen bond in imidazole crystal.

The hydrogen bond of the type N-H...N in imidazole crystal has been studied by one and two-dimensional 15N exchange CP/MAS NMR measurements as well as the powder NMR spectrum. The chemical shift anisotropies for -N= and -N< were determined from the powder 1D spectrum. In 2D exchange CP/MAS NMR spectrum, the cross peaks between the 15N main resonance peaks for -N= and -N< were observed, implying that magnetization exchange between -N= and -N< takes place. The 1D exchange CP/MAS NMR measurements determined the exchange rate of magnetization at 289 K to be 1.3 and 1.5 s(-1) for -N= and -N<, respectively. The proton-driven spin-diffusion model interprets the experimental values, and the exchange rate depends strongly on the RF power of the proton decoupling field, suggesting that the magnetization transfer between -N= and -N< takes place by the 1H-driven spin-diffusion mechanism.

Tyrosine phosphorylation increases Ca2+ sensitivity of vascular smooth muscle contraction.

In order to elucidate the role of tyrosine phosphorylation in vasoconstriction, we investigated the effects of inhibitors of tyrosine kinase (genistein, 30 microM) and phosphatase (sodium o-vanadate, 5 microM) on the contraction of aorta isolated from guinea pig. Genistein significantly inhibited norepinephrine-induced contraction, but it did not affect that induced by KCI. Thus, tyrosine phosphorylation may not be involved in the contractile response to KCI alone. The aortic contraction elicited by KCl was significantly augmented by sodium o-vanadate, which increased both the maximum force and pD2 values of KCl contraction. In the presence of verapamil, KCl-induced contraction was abolished even after pretreatment with sodium o-vanadate. Sodium o-vanadate also augmented Ca2+-induced contraction in the aortic strips depolarized with KCl, increasing both its maximum force and pD2 values. Neither basal 45Ca2+ uptake nor verapamil-sensitive 45Ca2+ uptake induced by KCl were affected by pretreatment with sodium o-vanadate. These results suggest that tyrosine phosphorylation is involved in the contraction of guinea-pig aorta not through transplasmalemmal Ca2+ entry but through increased Ca2+ sensitivity of the intracellular contractile pathway.

[Effects of low concentration of styrene monomer vapor on pregnancy].

To investigate the effects of exposure to styrene vapor on pregnancy, mice proved to be pregnant were exposed to 0, 2, 20 and 100 ppm styrene continuously for 24 hours during the period from day 0 to day 15 of gestation. A special small exposure chamber which can accurately maintain a constant low concentration of styrene vapor was made and used in the experiment. 1) In the 100 ppm group, hyperkinesis was presented in the chamber during the exposure period and inhibition of body weight gain was found (p < 0.01). No deaths occurred in any of the groups. 2) At necropsy of dams, no significant difference was found between the styrene exposed groups and the control group in any of the fertility indices, number of implantations, number of live fetuses, percentage of resorptions, or in the percentage of dead fetuses. The 100 ppm group showed lower fetal and placental weights (p < 0.01). 3) Gross necropsy of dams in the 100 ppm group showed significantly decreased adipose tissue. The liver, kidney and spleen weights were also low (p < 0.01). 4) When exposed to 100 ppm, which corresponds to 5 times the permissible concentration, i.e., 20 ppm, for 24 hours, non-pregnant dams showed no abnormality, while pregnant dams showed inhibition of body weight gain and significantly lower fetal and placental weights and maternal organ weights. Therefore, careful consideration should be given to exposure of women of childbearing age to styrene.

Binuclear 1,2,4,5-tetraimino-3,6-diketocyclohexane bis[bis(bipyridine)ruthenium(II)] redox series.

The reaction of the [Ru(bpy)2(MeOH)2]2+ cation (bpy = 2,2'-bipyridine) with 1,2,4,5-tetraaminobenzene in the presence of trace water and oxygen yields the cation [(bpy)2Ru(1,2,4,5-tetraimino-3,5-diketocyclohexane)Ru(bpy)2]4+. This binuclear species undergoes ligand-based reductions, giving the 3+ and 2+ charged species. The X-ray structure, electrochemistry, ZINDO calculations, and NMR, ESR, UV/vis, and IR spectra were analyzed where possible, giving an electronic model of the binuclear species and some of its redox products. The X-ray structure reveals the [(bpy)2Ru] fragments symmetrically disposed across the 1,2,4,5-tetraimino-3,5-diketocyclohexane bridge in a molecule with Cs symmetry.

[Efficacy of adjuvant hepatic arterial infusion chemotherapy following resection of colorectal liver metastases].

PURPOSE: The aim of this study is to evaluate the effect of adjuvant hepatic arterial infusion chemotherapy (HAIC) following liver resection on the frequency of residual liver recurrence and overall survival. PATIENTS AND METHODS: During 1992 to 1997, 84 patients with liver metastasis from colorectal cancer resected curatively had undergone adjuvant HAIC. The regimen of the HAIC is 1,500 mg of 5-FU by 24-hr continuous infusion once a week for eight weeks. 37 cases in the HAIC group, including patients given more than 7 g of 5-FU, were compared with the control group. RESULT: The cumulative 5-year liver recurrence-free ratios were 72.6% in the HAIC group and 29.8% in the control group (p = 0.0005). The cumulative 5-year survival ratios were 61.4% in the HAIC group and 28.0% in the control group (p = 0.0069). Multivariate analysis revealed that more than 5 mm of surgical margin and adjuvant HAIC significantly decreased the risk of recurrences in residual liver. CONCLUSION: Adjuvant HAIC is an effective procedure to prevent recurrence in residual liver and improve the prognosis of patients with liver metastasis from colorectal cancer.

Effect of maitake (Grifola frondosa) water extract on inhibition of adipocyte conversion of C3H10T1/2B2C1 cells.

We investigated the effect of maitake (Grifola frondosa) water extract on inhibiting the conversion of C3H10T1/2B2C1 cells into adipocytes. Maitake water extract was fractionated by molecular sieve. Heat-labile compounds strongly inhibiting adipocyte conversion proved to occur in fractions of molecular weight of more than 10,000 on the basis of activity measurement of glycerol-3-phosphate dehydrogenase.

[Mechanism of inhibitory effects of ethanol on gallbladder contraction: differences in cases of histamine- and acetylcholine-induced contraction].

We investigated the effects of different concentrations of ethanol on contraction of gallbladder isolated from guinea pig. Ethanol at 25 mM significantly inhibited the contraction induced by histamine, but not those by KCl and acetylcholine. A higher concentration (100 mM) of ethanol inhibited both histamine-, acetylcholine- and KCl- induced contractions. The inhibitory effect of the lower concentration (25 mM) of ethanol was not observed in the presence of verapamil, an antagonist of L-type Ca2+ channel or staurosporine, a selective inhibitor of protein kinase C. Verapamil and staurosporine significantly inhibited both histamine- and acetylcholine-induced contractile responses: the inhibitory effect was more potent for the histamine contraction. Our recent study has demonstrated that contraction caused by protein kinase C activation is completely dependent on Ca2+ influx through the L-type Ca2+ channel in gallbladder smooth muscle of guinea pig. Therefore, the difference in 25 mM ethanol effect on histamine- and acetylcholine-induced contractions may be due to different degree of involvement of protein kinase C activation in the agonist-induced contraction. On the other hands, the higher concentration (100 mM) of ethanol inhibits the common pathway of contraction in gallbladder smooth muscle cells.

Reducing-agents-mediated Solubilization and Activation of Debranching Enzyme (Pullulanase) in Rice Flour.

The effects of reducing agents on solubilization and activation of the debranching enzyme (pullulanase) were examined using rice flour. The activity of the debranching enzyme was observed in a buffer solution (pH 7.5) in which rice flour was incubated together with thiol-reducing reagents, (dithiothreitol, 2-mercaptoethanol etc.), but there was only low activity in the absence of reducing agents. Immunochemical measurement and the specific activity of the enzyme showed that the activation caused by the reductant was due to solubilization of the enzyme protein besides the enzyme activation.

Micrometastatic colorectal cancer lesions in the liver.

A surgical resection of metastatic liver lesions from colorectal cancer contributes to an improved prognosis. However, the postoperative recurrence rate remains high, particularly in the residual liver. This is probably the result of the failure to detect small lesions. In the present study, we histologically examined the presence of intrahepatic micrometastases, which are considered to be related to recurrence in the residual liver. Intrahepatic micrometastases were histologically examined in 31 resected specimens of 25 patients undergoing a hepatic resection because of metastasis to the liver from colorectal cancer. Micrometastases were found in 14 of 25 cases (56.0%). They were located in the portal veins, central veins, sinusoid, and bile ducts. The longest distance from the main metastasis was 38.2 (mean 7.5 +/- 8.0) mm. The size of the macrometastases became larger, and the frequency of micrometastases and the distance of micrometastases from macrometastases had a tendency to increase. Continuous invasion of the macrometastases into the micrometastases through the vasculature or bile duct was also observed. These results suggested that some micrometastases observed in the metastatic liver from colorectal cancer were thus seeded from the primary lesions, while other micrometastases originated from the macrometastatic lesions as satellite lesions.

A study of medical emergency workflow.

In this paper, the authors introduce a workflow model. The development of computer network technology enables us to share the distributed data in real time. It is a considerable significance in the practical application of network capabilities not only to office work but also to the medical environment. In order to construct a well-connected, managed post (environment, scene), a model is needed to design the workflow. Here we propose a workflow model to cope with the scene of unforeseen events that we usually encounter in daily clinical activities. We give careful consideration to the ability of this model to manage dynamic changes within the workflow and describe its application to a medical scene (triage) and then carry out simulations based on this model. The authors are able to demonstrate the validity of this model through this simulation.

Detection of regional lymph node metastases in colon cancer by using RT-PCR for matrix metalloproteinase 7, matrilysin.

Lymph node metastasis is the most important prognostic factor in colon cancer. However, more accurate screening for metastasis than that afforded by conventional pathology remains elusive. We have employed a reverse transcriptase-polymerase chain reaction (RT-PCR) assay for a matrix metalloproteinase (MMP), 'matrilysin', because this gene is epithelial-specific and consistently expressed in colorectal cancer cells. The sensitivity of this assay was examined with the matrilysin-producing rectal cancer cell line 'CaR-1'. Matrilysin mRNA was detected in this system when more than 10(4) matrilysin-positive cells existed in a lymph node of ordinary size. Fourteen of 15 (93%) primary colon cancers and none of the surrounding normal tissues expressed matrilysin. All 10 histologically-positive lymph nodes were positive for matrilysin, while of 60 histologically-negative lymph nodes, eight were positive for matrilysin. When the additional sequential sectioning and histological re-examination was performed on five of these eight 'matrilysin-positive, but histologically-negative' lymph nodes, micrometastases were detected in three. Only one of the lymph nodes that were histologically-positive, but negative by matrilysin assay was from a patient with colon cancer in which matrilysin was not detected. In conclusion, RT-PCR assay for matrilysin is a sensitive method for detecting occult metastases in patients with colon cancer, and may complement histologic examination.