Study on placental transmission of Pneumocystis carinii in mice using immunodeficient SCID mice as a new animal model.

Placental transmission of Pneumocystis carinii in mice was examined in 39 animals obtained by caesarean section from 17 pregnant SCID females experimentally infected with P. carinii. When examined with toluidine blue O, DAPI and immunofluorescent antibody stains, P. carinii was detected in the lungs of infected mothers but not in the lungs of caesarean section-derived neonates even after the neonates were treated with dexamethasone for 8 weeks. However, 13 neonates born to five infected females developed P. carinii pneumonia. These results indicate that P. carinii cannot be transmitted transplacentally in mice.     

Growth requirements and long-term subcultivation of bovine granulosa cells cultured in a serum-free medium

Summary We have developed an improved serum-free medium to optimize the cell growth of bovine granulosa cells. The cells on collagen-coated culture plates proliferated extensively in a nutrient medium supplemented with insulin, heparin binding growth factor-2 (HBGF-2), lipoprotein, and bovine serum albumin (BSA). The cell doubling time at logarithmic phase and final cell density at confluent cultures were equal to those of cultures grown in the presence of medium supplemented with optimal concentration (10%) of fetal bovine serum (FBS). Whereas HBGF-2 or insulin alone had a small mitogenic effect of granulosa cells, lipoprotein or BSA did not. When lipoprotein, BSA, or insulin was added together with HBGF-2, synergistic cell proliferation was observed in all combinations. Insulin or lipoprotein had an additive mitogenic stimulation of these cells in the presence of BSA. After granulosa cells were subcultivated in a serum-containing medium until three generations [8.5 cumulative population doubling level (CPDL)], subsequent subcultivation of the cells in a complete serum-free medium could be achieved up to six generations (14.4 CPDL). These results demonstrate that this serum-free medium can support the optimal cell growth and long-term subcultivation of bovine granulosa cells.     

Analytical method of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in human hair by column-switching liquid chromatography-mass spectrometry

A column-switching liquid chromatography-mass spectrometry was developed for quantification of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in human hair. Hair sample was digested in 1N NaOH at 100 degrees C, and PhIP was extracted using a Blue-Chitin column. The recovery rate was 73%, the limit of quantification was 50 pg/g hair, and intra-day and inter-day variations were 6.3 and 11.7%, respectively. PhIP was found in 42 of the 46 hair samples from 23 healthy volunteers: 110-3878 pg/g hair. The intrapersonal correlation between the first and second analyses was r = 0.85 (95% confidence interval, 0.65-0.94). A positive correlation was observed between PhIP levels and melanin content in hair. This study indicates the ability of this method to detect levels of PhIP in hair.     

Validity of self-reported cancer among a Japanese population: recent results from a population-based prospective study in Japan (JPHC Study)

The recent tendency of Japanese towards greater acceptance of being informed that they have cancer, along with the growing understanding and use of informed consent, appears to have improved the accuracy of self-reported cancer. To clarify the recent validity of self-reports, we measured the sensitivity and positive predictive value of self-reported cancer among a Japanese population. Using a 10-year follow-up questionnaire conducted in 2000-2004 and the cancer registry of the JPHC Study cohort (n=93,680), we calculated the sensitivity and positive predictive value of self-reported cancer diagnoses over 10 years. Sensitivity and positive predictive value of total self-reported cancer diagnoses were 53% and 60%, respectively, but varied by site, at 62% and 52% for stomach, 38% and 47% for colorectum, 57% and 46% for lung, 34% and 31% for liver, 82% and 58% for breast, and 59% and 22% for uterus, respectively. Sensitivity was considerably improved from that in the previous report (36%), which tested for 1990-1995, but was still not considered satisfactory. Self-reported diagnoses of cancer do not provide sufficient accuracy for the detection and classification of incident cancers. Our findings may be extrapolated to other Japanese populations.     

Adult Mortality Attributable to Preventable Risk Factors for Non-Communicable Diseases and Injuries in Japan: A Comparative Risk Assessment

Background

The population of Japan has achieved the longest life expectancy in the world. To further improve population health, consistent and comparative evidence on mortality attributable to preventable risk factors is necessary for setting priorities for health policies and programs. Although several past studies have quantified the impact of individual risk factors in Japan, to our knowledge no study has assessed and compared the effects of multiple modifiable risk factors for non-communicable diseases and injuries using a standard framework. We estimated the effects of 16 risk factors on cause-specific deaths and life expectancy in Japan.

Methods and Findings

We obtained data on risk factor exposures from the National Health and Nutrition Survey and epidemiological studies, data on the number of cause-specific deaths from vital records adjusted for ill-defined codes, and data on relative risks from epidemiological studies and meta-analyses. We applied a comparative risk assessment framework to estimate effects of excess risks on deaths and life expectancy at age 40 y. In 2007, tobacco smoking and high blood pressure accounted for 129,000 deaths (95% CI: 115,000–154,000) and 104,000 deaths (95% CI: 86,000–119,000), respectively, followed by physical inactivity (52,000 deaths, 95% CI: 47,000–58,000), high blood glucose (34,000 deaths, 95% CI: 26,000–43,000), high dietary salt intake (34,000 deaths, 95% CI: 27,000–39,000), and alcohol use (31,000 deaths, 95% CI: 28,000–35,000). In recent decades, cancer mortality attributable to tobacco smoking has increased in the elderly, while stroke mortality attributable to high blood pressure has declined. Life expectancy at age 40 y in 2007 would have been extended by 1.4 y for both sexes (men, 95% CI: 1.3–1.6; women, 95% CI: 1.2–1.7) if exposures to multiple cardiovascular risk factors had been reduced to their optimal levels as determined by a theoretical-minimum-risk exposure distribution.

Conclusions

Tobacco smoking and high blood pressure are the two major risk factors for adult mortality from non-communicable diseases and injuries in Japan. There is a large potential population health gain if multiple risk factors are jointly controlled. Please see later in the article for the Editors'' Summary     

A recessive Arabidopsis mutant that grows photoautotrophically under salt stress shows enhanced active oxygen detoxification.

Mutagenized Arabidopsis seedlings (ecotype Columbia) were screened for the ability to grow photoautotrophically on solid medium containing 200 mM NaCl. A novel mutant line, designated pst1 (for photoautotrophic salt tolerance1), was obtained. There were no significant differences between pst1 and wild-type plants with regard to their ability to induce proline as an osmoregulatory solute. In addition, the content of monovalent cations in pst1 plants grown with or without salt stress was equal to that in the wild type. We observed that light, even at moderate intensities, increased the effects of salt stress on wild-type plants. The pst1 seedlings were nearly 10 times more tolerant to methyl viologen than were wild-type seedlings. We also found that the activities of the active oxygen scavengers superoxide dismutase and ascorbate peroxidase were enhanced significantly in pst1 plants. The pst1 plants also were tolerant to other stresses, such as high light intensity and toxic monovalent cations. The recessive nature of the pst1 mutation indicates that the potential for salt-stress tolerance is blocked in wild-type Arabidopsis.     

Clinical Significance of IgG Antibody Titer against Helicobacter pylori

Background: We clarified the clinical significance of measurement of IgG antibody titers against Helicobacter pylori using data from a nested case–control study from a large-scale cohort study in Japan.
Method: Participants included 36,745 subjects from the Japan Health Center-based Prospective Study who responded to the baseline questionnaire and provided a blood sample. Subjects were aged 40–69 years and were followed over 15 years after initial sampling. Controls were matched to 511 gastric cancer patients. Plasma surface antigen (Hp)-IgG titer was measured using ELISA, and mucosal atrophy was determined by measuring pepsinogen I and II levels.
Results: Seropositive subjects with low Hp-IgG titer and mucosal atrophy showed a higher risk for gastric cancer than high-titer subjects. Odds ratio (OR) referred to cases with true negative IgG titers and no mucosal atrophy. In moderately atrophic subjects, the low titer OR was 19.0, with a 95% confidence interval (CI) of 7.7–46.9, and 12.5 for high titer, with a 95% CI of 5.2–30.0. In severely atrophic subjects, the low titer OR was almost double that of high-titer subjects (OR = 30.2, 95% CI = 12.4–73.7 and OR = 15.9, 95% CI = 6.3–40.3, respectively). These associations were observed more frequently for differentiated than undifferentiated gastric cancer.
Conclusion: Combination assay with Hp-IgG titer and pepsinogens may help identify groups at high risk for gastric cancer. Subjects with low Hp-IgG titer and mucosal atrophy were at extremely high risk for gastric cancer, particularly differentiated cancer. Subjects with this background may require ongoing observation and periodic endoscopic examination for early cancer detection.     

Calvasculin, an encoded protein from mRNA termed pEL-98, 18A2, 42A, or p9Ka, is secreted by smooth muscle cells in culture and exhibits Ca(2+)-dependent binding to 36-kDa microfibril-associated glycoprotein.

Calvasculin, an EF-hand protein with a molecular mass of 11 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is present abundantly in bovine aorta (Watanabe, Y., Kobayashi, R., Ishikawa, T., and Hidaka, H. (1992) Arch. Biochem. Biophys. 292, 563-569). This protein is synthesized constitutively by bovine aortic smooth muscle (BASM) cells and rat embryo fibroblast 3Y1 cells in culture. We discovered that calvasculin was secreted by BASM cells and 3Y1 cells. Immunofluorescence staining of BASM cells showed a granular distribution for calvasculin that was typical of a secreted protein. This protein bound with an extracellular matrix protein, 36-kDa microfibril-associated glycoprotein (36-kDa MAP), in a Ca(2+)-dependent manner in vitro. A stoichiometry analysis showed that the 36-kDa MAP bound 2.2 calvasculin eq/mol of protein. Solid-phase binding assays indicated a preferential affinity of native calvasculin for 36-kDa MAP among the extracellular matrices in a Ca(2+)-dependent manner. These results suggest that calvasculin, intracellular Ca(2+)-binding protein, is released to the extracellular space and binds with 36-kDa MAP.