Analytical high-resolution TEM study of supported gold catalysts: orientation relationship between Au particles and TiO2 supports

An analytical high-resolution TEM study was carried out for gold deposited on TiO2 (anatase and rutile) to obtain a structural insight into the unique catalytic properties of the system. Preferred orientations between Au particles and the TiO2 support were often observed and a model for the epitaxial orientation between the Au particles and anatase TiO2 was proposed. These results were consistent with the results calculated by the coincidence of reciprocal lattice point (CRLP) method.

Immunological and molecular comparison of polyphenol oxidase in Rosaceae fruit trees

An antibody raised against apple polyphenol oxidase (PPO) cross-reacted with PPOs from Japanese pear (Pyrus pyrifolia), pear (Pyrus communis), peach (Prunus persica), Chinese quince (Pseudocydonia sinensis) and Japanese loquat (Eriobotrya japonica). Core fragments (681 bp) of the corresponding PPO genes were amplified and characterized. The deduced protein sequences showed identities of 85.3 to 97.5%. Chlorogenic acid oxidase activity of these PPOs showed higher activities when assayed at pH 4 than at pH 6. These results indicate that PPOs in Rosaceae plants are structurally and enzymatically similar.

A historical cohort mortality study of workers exposed to asbestos in a refitting shipyard

To investigate the risks of developing asbestos-related diseases we conducted a historical cohort mortality study on 249 ship repair workers (90 laggers and 159 boiler repairers) in a single U.S. Navy shipyard in Japan. We successfully identified the vital status of 87 (96.7%) laggers and 150 (94.3%) boiler repairers, and, of these, 49 (56.3%) and 65 (43.3%) died, respectively, during the follow-up period from 1947 till the end of 1996. Our in-person interviews with some of the subjects clarified that asbestos exposure was considered to be substantially high in the 1950-60s, decreased thereafter gradually but remained till 1979 in the shipyard. The laggers, who had handled asbestos materials directly, showed a significantly elevated SMR of 2.75 (95% C.I.: 1.08-6.48) for lung cancer. The risk developing the disease was greater in the laggers after a 20-year latency (SMR = 3.42). Pancreatic cancer yielded a greater SMR than unity (7.78, 90% C.I.: 2.07-25.19) in a longer working years group. Four laggers died from asbestosis. The boiler repairers, who had many chances for secondary exposure to asbestos and a few for direct exposure, showed no elevation of the SMR of lung cancer overall, but there was a borderline statistically significant SMR of 2.41 (90% C.I.: 1.05-5.45) in a longer working years group. One boiler repairer died from mesothelioma and four from asbestosis.

Cloning genomic DNA encoding apple polyphenol oxidase and comparison of the gene product in Escherichia coli and in apple

Two PCR-amplified genomic DNA fragments encoding apple (cv. Fuji) polyphenol oxidase (PPO) were cloned and sequenced. A comparison of genomic DNA with cDNAs revealed that the PPOs lacked introns. Both PPO DNAs appear to encode a 66-kDa precursor protein consisting of a 56-kDa mature protein and a N-terminal transit peptide of 10-kDa N-terminal transit peptide. Apple PPO DNA was expressed in Escherichia coli, and the gene product (56 kDa) without a transit peptide was immunochemically detected and was the same size (ca. 65 kDa) as the main PPO of apple fruit by SDS-PAGE.

[Umbilical blood-gas status at cesarean section for breech presentation: a comparison with vertex presentation]

Umbilical blood-gas status at elective cesarean section with oxygen inhalation for breech presentation (25 cases) was compared with that for vertex presentation (25 cases), so as to confirm the security of full-term breech fetuses delivered by cesarean section under spinal anesthesia. Umbilical arterial oxygen levels were significantly lower in the breech group (Mean PO2:18.9 mmHg; SO2:37.3%; Oxygen content:7.6 ml/dl). The number of hypoxemic fetuses was significantly higher in the breech group (the breech: 7; the vertex; 0). The other umbilical blood-gas values revealed no significant differences between the breech and vertex groups, and were within normal limits in both groups. Oxygen extraction in the breech (Mean: 49.0%) was higher than that in the vertex (32.9%). Therefore decreased umbilical blood flow in the breech was suggested. The incidence of depression at 1 minute after delivery in the breech infants (24%) was significantly higher than that in the vertex infants (0%). It became obvious in the breech that as the interval between the uterine incision and delivery increased, umbilical arterial blood tended to acidosis and the 1 minute Apgar score decreased. Cesarean section for breech presentation requires sufficient and optimal incisions of the abdominal wall and uterus as well as a skillful manual delivery technique, because the fetus or neonate should be protected against asphyxia resulting from umbilical compression and prolonged delivery interval.

[Effects of maternal hyperventilation and oxygen inhalation during labor on fetal blood-gas status]

The effects of maternal hyperventilation and oxygen inhalation on fetal blood-gas status were studied in 54 fetuses, vaginally delivered of mothers without medical and obstetrical complications. The cases were divided into four groups according to MA (maternal arterial) pH and PCO2 values and by respiring either oxygen or room-air as follows. Group N: pH less than 7.5, PCO2 greater than 23 mmHg (normoventilation), without maternal oxygen inhalation, group H: pH greater than 7.5, PCO2 less than 23 mmHg (hyperventilation), without oxygen inhalation, group NO: pH less than 7.5, PCO2 greater than 23 mmHg, with oxygen inhalation and group HO: pH greater than 7.5, PCO2 less than 23 mmHg, with oxygen inhalation. Umbilical venous (UV) PO2 (27.8 mmHg: mean), SO2 (60.8%) and CO2 (oxygen content, 12.4 ml/dl), and umbilical arterial (UA) PO2 (17.9 mmHg), SO2 (35.6%) and CO2 (7.3 ml/dl) values in group H were significantly lower than those in group N. The fetal oxygenation in group HO was similar to that in group N, and the fetal oxygen values in group NO were significantly higher than those in the other groups. The fetuses in groups H and HO tended to respiratory alkalosis. The UV oxygen values had negative correlations with MA pH and positive correlations with the MA PCO2 value in both oxygen and no-oxygen groups. There was no significant correlation between maternal and fetal PCO2 values, and higher fetal oxygen extraction (41%: mean) in group H. These facts suggest that severe maternal respiratory alkalosis due to hyperventilation may lead to a disorder in placental circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ephedrine administration for cesarean section under spinal anesthesia]

Prophylactic ephedrine was administered to healthy parturients undergoing elective cesarean section under spinal anesthesia. The methods of ephedrine administration were as follows: intramuscular injection of 0.3 mg/kg, 15 minutes before the block (20 cases: group M), infusion of 0.02% solution immediately after the block (20 cases: group D), premedication with atropine 0.5 mg and infusion immediately after the block (20 cases: group AD). The mean ephedrine dosage was 18.8 +/- 2.2 gm (SD) in group M, 12.6 +/- 6.2 mg in group D and 5.2 +/- 0.7 mg in group AD, and there were significant differences among the three groups. The base line (a), the minimal postanesthetic (b) and the maximal postpartum systolic blood pressures (c) revealed no significant difference among the three groups, and 'b' was significantly higher than 'a' and lower than 'c' in all groups. Only one case (group M) was transiently hypotensive, while hypertension was not found in any of the subjects. One- and 5-minute Apgar scores were 8 or more in all, and umbilical acid-base values were within normal limits in all of them, though the base deficit in group AD was significantly lower than that in group M. Atropine premedication makes it possible to retrench the ephedrine dosage without any harmful effect on either mother or fetus, and ephedrine infusion makes it easy to cope with changes in maternal blood pressure. Consequently, for healthy parturients receiving elective cesarean section under spinal block, we recommend atropine premedication and minimal infusion of ephedrine immediately following the block.

[Neonatal effects of the delivery interval during cesarean section under spinal anesthesia]

The relationships between I-DI (induction to delivery interval) or U-DI (uterine incision to delivery interval) and fetal acid-base status or neonatal clinical condition were studied in 60 healthy parturients undergoing elective cesarean section under spinal anesthesia. The patients were divided into groups, i.e. group A (U-DI less than 90 sec, I-DI greater than 14 min, 18 cases), group B (U-DI less than 90 sec, I-DI greater than 14 min, 12 cases), group C (U-DI greater than 90 sec, I-DI less than 14 min, 15 cases) and group D (U-DI greater than 90 sec, I-DI greater than 14 min, 15 cases). Acid-base values for maternal arterial (MA), umbilical venous (UV) and umbilical arterial blood (UA), and acid-base gradients for (MA-UV) and (UV-UA) in each group were all in the normal range and revealed no significant differences among 4 groups, though U-DI was correlated with UVPCO2, UAPCO2, and (UV-UA) base deficit (r = 0.322, 0.266, -0.256: p less than 0.05). Acid-base states in cases of long and excessively long U-DI (greater than 90 sec and greater than 150 sec, respectively) were more acidotic than those of short U-DI groups (less than 90 sec). Both 1 and 5 minute Apgar scores were 8 or more in all neonates. There was no correlation between I-DI and fetal acid-base values or neonatal clinical conditions. It is conceivable that gentle and careful manipulations of the uterus and fetus rather than shortening of U-DI might be important in preventing against fetal or neonatal depression during cesarean section under spinal block.