Unique Asymmetric Protrusion of Nerve Cord in the Amphioxus, Branchiostoma belcheri

The amphioxus is the only surviving prevertebrate segmented chordate. In this animal Hatschek's pit has long been regarded as a putative homologue of the adenohypophysis because of the presence of secretory granules and immunoreactive cells to vertebrate gonadotrophic hormone in this organ. We found that the nerve cord extends a protrusion to the pit along the right side of the notochord. Furthermore, secretory granules were found not only in the pit but also in the protrusion of the nerve cord. These results suggest that Hatschek's pit and the nerve protrusion are homologous to the adenohypophysis and neurohypophysis, respectively. We believe that this is an evidence for the presence of the neuroendocrine link between the central nervous system and Hatschek's pit in the amphioxus. Received: 2 November 1998 / Accepted in revised form: 11 February 1999     

Asymmetric hydrogenation using modified ion exchange resin-palladium catalysts

The Science of Nature -     

T cell-derived IL-5 production is a sensitive target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

The immune system is one of the organs most vulnerable to the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Among the various immunotoxic effects of TCDD, the thymus involution and suppression of IgM antibody production are well known sensitive reactions of the thymocytes and B cells affected by TCDD. Recently, we reported that TCDD greatly inhibits the production of type-2 helper T (Th2) cell-derived cytokines, especially IL-5, by the splenocytes in mice immunized with ovalbumin (OVA). In the present study, we investigated the dose-dependency of these TCDD immunotoxic effects in OVA-immunized mice to identify the most sensitive target. Mice of two age groups, 6 weeks old and 3 weeks old, were dosed with 0.3, 1.0, or 3.0 microg TCDD/kg and immunized with OVA using alum as an adjuvant. Seven days later, the thymus weight, thymocyte population, antigen-specific IgM in the plasma, and IL-5 production by the splenocytes were examined. Among them, IL-5 production was significantly suppressed by all three doses of TCDD and reduced to about 30% by even a small dose of 0.3 microg TCDD/kg in both age groups. The thymus weight was significantly reduced by 1.0 microg or 3.0 microg TCDD/kg, but IgM production was not affected by up to 3.0 microg/kg of TCDD in both age groups. Taken together, the Th2 cell-derived IL-5 production was the most sensitive endpoint detecting TCDD toxicity among those examined. Our results also suggest that effector T cells are targets more vulnerable to TCDD toxicity than thymocytes or antibody-producing B cells in the OVA-immunized mice.     

Prenatal diagnosis of triple X using fetal cells obtained by endocervical lavage

Prenatal diagnosis of aneuploidies currently relies on invasive procedures such as chorionic villous sampling and amniocentesis. These methods can provide an accurate diagnosis of the fetal karyotype but are relatively invasive. Here, we report a case of the prenatal detection of triple X using fetal cells obtained by lavage of the endocervical canal prior to amniocentesis, following ultrasound diagnosis of hydrops fetalis. Copyright © 2003 John Wiley & Sons, Ltd.     

Comparison of chorionic villus sampling and amniocentesis: Current status of prenatal diagnosis in Japan

Data were tabulated and compared for cases involving prenatal diagnostic procedures performed in the 8 years between January 1985 and December 1992. Of a total of 2781 pregnancies, 2546 cases (91·5 per cent) were diagnosed by amniocentesis, and 235 (8·5 per cent) by chorionic villus sampling (CVS). These findings reflect the fact that amniocentesis has taken deep root as the prenatal diagnostic procedure widely acknowledged by society, whereas even the existence of CVS has yet to be generally recognized. Analysis of our clinical and laboratory results and complication rates, however, suggests that CVS is a safe and accurate alternative to amniocentesis which should and can be positively presented to all patients who are candidates for prenatal diagnosis.     

Life history trade-offs in tropical trees and lianas

It has been hypothesized that tropical trees partition forest light environments through a life history trade-off between juvenile growth and survival; however, the generality of this trade-off across life stages and functional groups has been questioned. We quantified trade-offs between growth and survival for trees and lianas on Barro Colorado Island (BCI), Panama using first-year seedlings of 22 liana and 31 tree species and saplings (10 mm < dbh < 39 mm) of 30 tree species. Lianas showed trade-offs similar to those of trees, with both groups exhibiting broadly overlapping ranges in survival and relative growth rates as seedlings. Life history strategies at the seedling stage were highly correlated with those at the sapling stage among tree species, with all species showing an increase in survival with size. Only one of 30 tree species demonstrated a statistically significant ontogenetic shift, having a relatively lower survival rate at the sapling stage than expected. Our results indicate that similar life history trade-offs apply across two functional groups (lianas and trees), and that life history strategies are largely conserved across seedling and sapling life-stages for most tropical tree species.     

Evaluating multiple emission pathways for fixed cumulative carbon dioxide emissions from global-scale socioeconomic perspectives

Recent climate modeling studies have concluded that cumulative carbon emissions determine temperature increase, regardless of emission pathways. Accordingly, the optimal emission pathway can be determined from a socioeconomic standpoint. To access the path dependence of socioeconomic impacts for cumulative carbon emissions, we used a computable general equilibrium model to analyze impacts on major socioeconomic indicators on a global scale for 30–50 pathways with different emission reduction starting years, different subsequent emission pathways, and three different cumulative 2100 emission scenarios (emissions that meet the 2 °C target, the 2 °C target emissions plus 10 %, and emissions producing radiative forcing of 4.5 W/m²). The results show that even with identical cumulative emission figures, the resulting socioeconomic impacts vary by the pathway realized. For the United Nations 2 °C target, for example, (a) the 95 % confidence interval of cumulative global gross domestic product (GDP) is 1355–1363 trillion US dollars (2010–2100, discount rate = 5 %), (b) the cumulative GDP of pathways with later emission reduction starting years grows weaker (5 % significance level), and (c) emissions in 2100 have a moderate negative correlation with cumulative GDP. These results suggest that GDP loss is minimized with pathways with earlier emission reduction followed by more moderate reduction rates to achieve lower emission levels. Consequently, we suggest an early emission peak to meet the stringent target. In our model setting, it is desirable for emissions to peak by 2020 to reduce mitigation cost and by 2030 at the latest to meet the 2 °C target.     

Prenatal diagnosis of harlequin ichthyosis by fetal skin biopsy; Report of two cases

Two cases of harlequin ichthyosis were successfully diagnosed prenatally by fetal skin biopsy. The aborted fetuses were later confirmed to be afflicted with this very unusual skin disease. Both families had a previous history of harlequin ichthyosis. In performing the biopsy, it was found that amniotic fluid cytology can also be very helpful in the diagnosis of this kind of severe ichthyosis. With regard to these families, the disease may have been transmitted in an autosomal dominant fashion, and not in a recessive manner as is commonly believed.     

Successful genetic bioaugmentation with Pseudomonas putida for toluene degradation in soil columns

There is a strong need for effective and sustainable treatment methods for remediating soils and waters contaminated by fossil fuel pollutants such as aromatic hydrocarbons. Remediation could be improved by genetic bioaugmentation that uses conjugation of catabolic plasmids between bacteria. Research on the conditions for success, effectiveness, and long-term impact of genetic bioaugmentation are therefore necessary. Here the effects of genetic bioaugmentation with Pseudomonas putida BBC 443 was studied in continuous-flow soil columns with or without glucose amendment. Results show that the highest transconjugant occurrence of 21.7 ± 2.1 %, and development of microbial communities with the highest overall toluene degradation potential of 0.0790 ± 0.0055 mg toluene/g soil/h, were achieved in soil columns that received a continuous addition of 1 g/L glucose. Plasmid transfer and toluene biodegradation did not depend on the survival of donor P. putida BBC443, suggesting that genetic bioaugmentation was successful. Furthermore, bacterial community structure analysis revealed that genetic bioaugmentation had limited long-term impact on the soil bacterial community structures, regardless of the specific treatment. Our findings show that genetic bioaugmentation was successful and resulted in limited long-term ecological impact, thus demonstrating that genetic bioaugmentation can provide an effective and sustainable method for in situ bioremediation.