Water content distribution in a polymer electrolyte membrane for advanced fuel cell system with liquid water supply

To better understand the operation of a new fuel cell design, we used magnetic resonance imaging (MRI) to measure the water content distribution in a polymer electrolyte membrane under fuel cell operation with and without a supply of liquid water. The supply of liquid water to the membrane improved the cell performance by increasing the water content in the membrane and thus reducing the electrical resistance of the membrane. The study also showed that MRI is a promising method to investigate the distribution of water in the membrane of a fuel cell under operating conditions.

Velocity measurement of clay intrusion through a sudden contraction step using a tagging pulse sequence

Magnetic resonance imaging (MRI) with a spatial tagging sequence was used to measure the velocity distribution of clay that was forced past a sudden contraction. A spatial tagging sequence provided magnetic resonance images of clay that allowed measurement of the velocity distribution in the clay, which can provide profound insights on the deformation process of clay during the intrusion process. The experiments were conducted using a specially-designed vessel that could operate at up to 30 MPa. The vessel offers a rectangle test section with a sudden contraction step that had a ratio of contraction of 2:1. The vessel was installed into a commercial magnetic resonance imaging equipment and then the fluid motion of clay flowing into the narrow contracted channel was quantitatively investigated to examine behaviors of flowing clay as non-Newtonian fluid. MRI results are compared with those obtained by computational fluid dynamics (CFD) calculation. Velocity distributions obtained from each tag displacement did not well agree with those predicted by CFD results near the contraction step where the fluid accelerated rapidly. However, a post-processing on calculation results, in which virtual tag displacement is calculated, gave better agreement with experiment and enabled us to compare MRI results with CFD results.

Low amplification and fast visual pigment phosphorylation as mechanisms characterizing cone photoresponses

Vertebrate cone photoreceptors are known to show lower light sensitivity and briefer photoresponses than rod photoreceptors. To understand the molecular mechanisms characterizing cone photoresponses, we compared some of the reactions in the phototransduction cascade between rods and cones. For this purpose, rods and cones were obtained in quantities large enough to do biochemical studies. The cells were purified from the retina of carp (Cyprinus carpio) with a stepwise Percoll gradient. The purified rod fraction contained almost no other kinds of cells besides rods, and the purified cone fraction contained a mixture of red-, green-, and blue-sensitive cones in the ratio 3: approximately 1: approximately 1. We prepared membrane preparations from the rod and the cone fraction, and in these membranes, we measured activation efficiencies of the reactions in the phototransduction cascade. The results showed that the signal amplification is lower in the cone membranes, which accounts for the lower light sensitivity in cones. Furthermore, we measured the time courses of visual pigment phosphorylation. The result showed that the phosphorylation is much faster in the cone membranes, which also explains the lower light sensitivity and, in addition, the briefer photoresponse in cones.

[Remyelination by Schwann cell transplantation for CNS demyelinated axons: functional comparison with developmental myelination]

Transplantation of Schwann cells(SCs) induced remyelination of demyelinated rat dorsal column(DC) axons and improved conduction. To investigate the difference between developmental oligodendrocytic myelination and SC myelination in conductive functions of axons, we compared normally developmental DCs(10 days old, 22-23 days old, and adult rat), demyelinated DCs, and remyelinated DCs by SC transplantation. DCs of adult rats were demyelinated at T 11 by X-ray irradiation and ethidium bromide, and transplanted with SCs(3 x 10(4)) of adult rats. Three weeks later, the spinal cord was removed and pinned in a recording chamber and compound action potentials (CAPs) were recorded, to investigate conduction properties(conduction velocity, amplitude of CAP and response after high frequency stimulation). Normal DCs were recorded in same manner. Following transplantation of SCs, histological examination revealed SC-like patterns of remyelination of demyelinated axons. The conduction velocities of 10 days old DCs(1.7 +/- 3.4 m/s, n = 4) increased early to 8.1 +/- 3.3 m/s(22-23 days old, n = 7) and 12.2 +/- 1.5 m/s (adult, n = 5). After SC transplantation the velocity significantly improved 7.7 +/- 1.5 m/s(n = 5) compared to demyelinated axons(1.2 +/- 0.4 m/s, n = 7), but less than adult. A 600 Hz 0.5 sec stimulus train led to an amplitude decrement of 7.1 +/- 7.5%(n = 7) in demyelinated axons. Following transplantation, amplitude decreased in 66.2 +/- 11.9%(SC, n = 5), same as 22-23 days(71.7 +/- 11.7%, n = 7) old or adult(76.6 +/- 15.6%, n = 6). The recovery properties after high frequency stimulation developed earlier than conduction velocity. Following SC transplantation, the recovery properties improved to that of normal adult, but not conduction velocity. Lower conduction velocity may be due to shorter internode distance of remyelination after transplantation, same as 22-23 days old pups, than normal adult rats. Though anatomical difference and/or time after transplantation influenced the conduction, these result suggested SC remyelination might result in insufficient for conduction velocity.

Reappraisal of single-sample and gamma camera methods for determination of the glomerular filtration rate with 99mTc-DTPA

The aim of this study was to assess the clinical validity of single-sample methods and gamma camera uptake methods with 99mTc-DTPA for the estimation of the glomerular filtration rate (GFR). The study was performed in 50 patients with various degrees of renal function (29 males and 21 females; age 27-90 yrs; serum creatinine level 0.34-6.49 mg/dl). As a reference the "true" GFR (GFRt) was determined from plasma clearance by means of the two compartment model curve fitting 10 plasma samples. The GFRt of more than 30 ml/min in 46 patients was compared to the GFR which was estimated with 7 single-sample methods, two gamma camera uptake methods and 24-hour endogenous creatinine clearance (24hCcr). Close correlation was observed in all single-sample methods. The highest linear correlation was observed in the Christensen and Groth's method rewritten by Watson for a 180-min plasma sample (r = 0.991, see = 5.84 ml/min). The smallest random error was observed in the Groth and Aasted's method for a 180-min plasma (r = 0.989, see = 4.31 ml/min/1.73 m2). Our method was lowest in % absolute difference analysis (mean = 4.10%). The gamma camera uptake methods correlated significantly with the GFRt (r = 0.746-0.774), but were less reliable than any of the single-sample methods (see = 15.41 ml/min-19.14 ml/min). The lowest correlation was observed in the 24hCcr (r = 0.698, see = 50.76 ml/min/1.73 m2). The single-sample method was more accurate than the gamma camera method, and the gamma camera method was more accurate than 24hCcr. The single-sample method should be recommended for the accurate determination of the GFR with 99mTc-DTPA in a patient with mild to moderate renal dysfunction.

[Single-blood-sample method for the determination of glomerular filtration rate using 99mTc-DTPA in Japanese]

The study was aimed to evaluate glomerular filtration rate with 99mTc-DTPA by means of a single-plasma-sample method in Japanese. Three were 50 patients (29 males and 21 females, age range being 25 to 91 years) with diabetes mellitus of various degree of the renal function. 99mTc-DTPA of 300 MBq/2 ml that was prepared in our hospital was injected. Dynamic renal scintigraphy was carried out and 10 blood samples were taken after the injection. Blood clearance (true GFR) of 99mTc-DTPA was determined from plasma concentration which was fitted to the biexponential curve by a non-linear least squares method. Plasma concentration (ml/min/1.73 m2) after 75 min-post injection showed very higher linear regression and linear correlation with true GFR than 0.900. The best linear regression and linear correlation was observed with 180 min-sample (r = 0.989). As general, the following equation was obtained; Y = A + Bln(X), A = 436.1217 - 3.45817t + 0.01205t2 - 0.000015t3, B = -212.601 + 1.42518t - 0.04834t2 + 0.0000062t3, X = plasma concentration at sampling time t (%ID/L/1.73 m2), t = sampling time from 75 to 300 min (r > 0.900). This is the new equation of single-plasma-sample method for the determination of GFR using 99mTc-DTPA for Japanese. The clinical feasibility should be accessed in a field of a nuclear medicine practice.

Isolation and characterization of IS1416 from Pseudomonas glumae, a new member of the IS3 family

Isolation and characterization of four different insertion sequence (IS) elements from Pseudomonas glumae MAFF 302744 through transposition into the entrapment vector pSHI1063 are described. One of the elements, IS1416, was further characterized. IS1416 is 1322 bp long and carries 29-bp terminal inverted repeats flanked by a 3-bp direct duplication. IS1416 contains three open reading frames (ORFs), which are designated ORFA1, ORFA2, and ORFB, on one strand. Both DNA sequence of IS1416 and the deduced amino acid sequences of its ORFs strongly suggest that IS1416 is a member of the IS3 family, and is closely related to IS401 from Pseudomonas cepacia and IS51 from Pseudomonas syringae. To our knowledge, IS1416 is the first IS element isolated from P. glumae. The gene organization and possible regulation of transposition functions of IS1416 are also discussed.

Family characteristics and offspring growth in various countries. I. Frequency of various family types in Bulgaria, Japan, Korea, Mexico and Poland

9936 families were analyzed from Bulgaria, Japan, Korea, Mexico, and Poland. A factor analysis revealed four factors: culture (F1), income (F2), genetics (F3), and family and apartment size (F4). Family types we coded as 1 if below the median and 2 if above the median. The most frequent types were represented by 1122, 2221, and 2211 (frequency 8.7-8.0%), and the least frequent by 1221 and 2111 (frequency 4.2-4.3%). Some similarity with respect to family types were found between populations: from Polish regions with heavy industry and seaside regions; from Polish towns under industrialization and from Mexico; from the Polish medium-size town of Lublin and Bulgarian towns; from Polish villages; from Polish mountain areas and north-eastern towns; from Korea; from Japan; from Polish cities.

Beneficial effects of TCV-309, a novel potent and selective platelet activating factor antagonist in endotoxin and anaphylactic shock in rodents

Pharmacological profiles of a novel specific platelet activating factor (PAF) antagonist, TCV-309 (3-bromo-5-[N-phenyl-N-[2-[2- (1,2,3,4-tetrahydro-2-isoquinolycarbonyloxy)ethyl] carbamoyl]ethyl] carbamoyl]-1-propylpyridinium nitrate] and its beneficial effects in shock were examined. TCV-309 specifically inhibited PAF-induced aggregation of rabbit and human platelets, and [3H]PAF binding to rabbit platelet microsomes with IC50 values of 33, 58 and 27 nM, respectively. It was as potent as WEB 2086 and more potent than CV-6209 and CV-3988. TCV-309 did not cause hemolysis in human or rat blood due to a detergent-like action. In rats, TCV-309 selectively inhibited the PAF-induced hypotension, hemoconcentration and death with ED50 values of 2.7, 6.4 and 1.7 micrograms/kg (i.v.), respectively. TCV-309 most potently protected mice from death induced by PAF and due to anaphylactic shock with ED50 values of 2.1 and 2.6 micrograms/kg (i.v.), respectively, when compared with CV-3988, CV-6209, WEB 2086 (i.v.) and L-652731 (p.o.). TCV-309 also reversed PAF-induced hypotension and endotoxin-induced hypotension in rats with ED50 values of 3.3 and 1.2 micrograms/kg (i.v.), respectively. There was a significant linear relationship between the ability (ED50 value) of these PAF antagonists to prevent death induced by PAF and death due to anaphylactic shock in mice, and between their reversing ability (ED50 value) for the hypotension induced by PAF and endotoxin in rats. TCV-309 (100 micrograms/kg i.v.) protected rats from death induced by endotoxin. Thus, PAF may be a lethal mediator in anaphylactic shock and a hypotensive mediator in endotoxin shock in rodents.

[Participation of regional inhabitants in cancer screening]

As part of the strategic planning for increasing participation by community residents in cancer screening, a survey about life style and attitudes toward cancer screening was carried out in Samukawa town, Kanagawa Prefecture. Subjects were males 40 years old or over, and females 30 years old or over selected by random sampling from residents. Number of subjects was 1,916 (822 males, 1,094 females). Self administered anonymous questionnaires were sent and returned by mail. The response rate was 73%. The results were as follows: (1) The reported participation rates for cancer screening under "the Health and Medical Services Law for the Aged" did not reflect the actual participation rate of residents. (2) The major reason for not participation in screening was lack of interest in cancer prevention. (3) Socio-economic status of regular participants in screening was different from persons who did not participate. (4) Persons who did not participate in screening were more passive with regard to obtaining knowledge of cancer than regular participants. (5) Results of this study show that cancer prevention education at various levels such as by clinical offices, TV and radio programs, and newspapers may be effective. In order to increase participation in screening programs, health education that considers the life style characteristics of persons who do not participate in the screening programs is vitally important.

Platelet activating factor antagonists: synthesis and structure-activity studies of novel PAF analogues modified in the phosphorylcholine moiety

New analogues of platelet activating factor (PAF), in which the phosphate and trimethylammonium moieties were replaced with an acylcarbamoyl moiety and a quaternary cyclic ammonium group, were synthesized. Their biological activities as PAF antagonists were evaluated by the inhibition of PAF-induced rabbit platelet aggregation in vitro and protective effects on PAF-induced hypotension in rats and PAF-induced death in mice. Investigation of structure-activity relationships revealed that PAF antagonist activity is strongly influenced by the acyl substituent of the nitrogen atom on the carbamoyl group and the nature of the polar head group at the 3-position of the glycerin backbone. Among the compounds tested, 2-[[N-acetyl-N-[[2-methoxy-3-[ (octadecylcarbamoyl)oxy]propoxy]-carbonyl]amino] methyl]-1-ethylpyridinium chloride (21, CV-6209) was one of the most potent compounds in the in vitro assay (IC50 = 7.5 X 10(-8) M) and the most potent and long-lasting in the in vivo assays. (R)-(-)-21 and (S)-(+)-21 were also synthesized, and no significant differences were observed in PAF antagonist activity in vitro and an inhibitory effect on PAF induced hypotension in vivo between (RS)-21 and its enantiomers.

[Production of human monoclonal autoantibodies that react with islet-cell-surface antigens by EBV-transformed lymphocytes: new method of preselection of ICSA producing lymphocyte by protein A magnetic microspheres]

Because of the low titer of ICSA, as well as the polyclonality of serum, it has been difficult to determine whether there is a variety of autoantibodies, each reacting with a different organ, or whether the autoimmune response is more restricted, with only a limited number of autoantibodies recognizing common antigenic determinants in the different organs. To study this and other questions, we sought to prepare human monoclonal autoimmune ICSA. Peripheral-blood lymphocytes from patients with freshly onset IDDM or other autoimmune abnormalities were transformed by EB virus. And rapid screening on In 111 cells by an ELISA were used to identify monoclonal ICSA. But, ICSA titer was very low even in freshly onset IDDM patients, and reduced very quickly. ICSA positive wells at cloning were extremely rare. So, the methods that enhance the efficiency of cloning were required. Firstly, ultrasensitive Enzyme Immunoassay for ICSA were developed. Secondly, new preselection method of ICSA producing lymphocyte by Protein A Magnetic Microspheres were employed. Thirdly, in vitro immunization was partly employed to enhance the frequency of ICSA producing lymphocytes. Fourthly, EBV-hybridoma technique was employed to stabilize the ICSA producing clone. The efficiency of cloning was increased from 0.07% to 24% by the new preselection method. The sensitivity of the fluorometric enzyme immunoassay for ICSA was 140pg/ml. 21 times sensitivity to usual ELISA was obtained. We describe sure methods for production of Human Monoclonal Autoantibodies that react with Islet-Cell-Surface Antigens.

CV-6209, a highly potent antagonist of platelet activating factor in vitro and in vivo

2-[N-acetyl-N-(2-methoxy-3-octadecylcarbamoyloxypropoxycarbonyl) aminomethyl]-1-ethylpyridinium chloride (CV-6209) inhibited aggregation of rabbit and human platelets induced by platelet activating factor (PAF) with the IC50 values of 7.5 X 10(-8) and 1.7 X 10(-7) M, respectively, and had little effects on the aggregation induced by arachidonic acid, ADP and collagen. The inhibitory effect of CV-6209 on the PAF-induced rabbit platelet aggregation was 104, 9, 8 and 3 times more potent than the PAF antagonists CV-3988, ONO-6240, Ginkgolide B and etizolam, respectively. CV-6209 inhibited [3H]serotonin release from rabbit platelets stimulated with PAF (3 X 10(-8) M) with a similar potency as the inhibition on the platelet aggregation. CV-6209 inhibited PAF (0.3 microgram/kg i.v.)-induced hypotension in rats (ED50, 0.009 mg/kg i.v.) with no effect on the hypotension induced by arachidonic acid, histamine, bradykinin and isoproterenol. CV-6209 (1 mg/kg) inhibited slightly the acetylcholine-induced hypotension. In rats, post-treatment with CV-6209 reversed the PAF (1 microgram/kg i.v.)-induced hypotension rapidly (ED50, 0.0046 mg/kg i.v.); CV-6209 was 74, 20, 185 and over 2100 times more potent than CV-3988, ONO-6240, Ginkgolide B and etizolam, respectively. Thus, the relative potency of the anti-PAF action of PAF analog (CV-6209, CV-3988 and ONO-6240) differed little between the inhibition of PAF-induced platelet aggregation and the reversal of PAF-induced hypotension, but that of nonPAF analogs (Ginkgolide B and etizolam) differed greatly with these assay systems, when standardized with CV-6209.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of the activity of a platelet activating factor antagonist, CV-3988

CV-3988 inhibited the vascular permeability increase induced by C16-PAF and C18-PAF in rat skin in a dose-dependent manner. The inhibition was shown to be specific and competitive with PAF on its receptor by the following observations: parallel shift of the dose-response curve; crossing of double reciprocal plots on the intersection of the ordinate; and no inhibition on other autacoids such as bradykinin, histamine, 5-hydroxytryptamine and LTC4. PAF-induced blood pressure fall in rats was also suppressed by pretreatment with CV-3988 selectively.

Activation of mouse peritoneal macrophages by synthetic glyceroglycolipid liposomes

Liposomes composed of chemically synthesized glyceroglycolipids, such as 1,2-dipalmityl-[beta-cellobiosyl-(1'----3)]- glycerol (Cel-DAG), 1,2-dipalmityl-[beta-lactosyl-(1'----3)]-glycerol, or 1,2-dipalmityl-[beta-maltosyl-(1'----3)]-glycerol, were found to enhance protective immunity against transplantable tumor cells (sarcoma 180) in ICR mice. Peritoneal exudate cells prepared from mice treated in vivo with Cel-DAG showed cytostatic activity in vitro against the mouse leukemia cell line, EL-4. Adherent cells separated from this preparation showed similar activity. Peritoneal cells from polypeptone-injected mice acquired appreciable cytostatic activity when incubated in vitro in the presence of glyceroglycolipid liposomes. The adherent cell fraction alone showed rather weak cytostatic activity when pretreated with the glyceroglycolipids, and full activity was restored by supplementing with the nonadherent cell fraction. The ability of glycolipids to induce tumoricidal effects was affected by cholesterol content: with increasing cholesterol content, the activities decreased. Cholesterol-free glycolipid liposomes were taken more efficiently by macrophages than cholesterol-containing liposomes. Cholesterol modifies the surface property of glyceroglycolipid liposomes. Activation of macrophages is responsible for enhancement of protective immunity against tumor cells by injection of these glycolipids in vivo.