Characteristics of Xeroderma Pigmentosum in Japan: Lessons From Two Clinical Surveys and Measures for Patient Care

Xeroderma pigmentosum (XP) is a rare autosomal recessive hereditary disease caused by deficiency in repair of DNA lesions generated by ultraviolet radiation and other compounds. Patients with XP display pigmentary change and numerous skin cancers in sun‐exposed sites, and some patients show exaggerated severe sunburns even upon minimum sun exposure as well as neurological symptoms. We conducted a nationwide survey for XP since 1980. In Japan, the frequency of the XP complementation group A is the highest, followed by the variant type; while in the Western countries, those of groups C or D are the highest. Regarding skin cancers in XP, basal cell carcinoma was the most frequent cancer that afflicted patients with XP, followed by squamous cell carcinoma, and malignant melanoma. The frequency of these skin cancers in patients with XP has decreased in these 20 years, and the age of onset of developing skin cancers is higher than those previously observed, owing to early diagnosis and education to patients and care takers on strict prevention from sunlight for patients with XP. On the other hand, the effective therapy for neurological XP has not been established yet, and this needs to be done urgently.     

NHC-coordinated palladacycle catalyzed 1,2-addition of arylboronates to unactivated ketones

Abstract

Palladium catalyzed intermolecular 1,2-addition of arylboronate to unactivated ketone was investigated. NHC-coordinated palladacycle 4c exhibited catalytic activity for the reactions and provided the corresponding tertiary alcohols and γ,γ-disubstituted γ-lactones in good to excellent yields.     

New type of trimeric and pentameric indole alkaloids from Psychotria rostrata

Two new tryptamine-related alkaloids, psychotrimine and psychopentamine, were isolated from the leaves of Psychotria rostrata, and their novel structures were elucidated on the basis of spectroscopic analyses.     

Molecular weight determination of polyamides by vapor pressure osmometry

The vapor pressure osmometry method for determining the molecular weight of polyamides has been studied by use of the newly developed solvents. Polymers used were polycaprolactams, polyenanthamides, and polypelargonamides. The measurements were carried out with 2,2,3,3-tetrafluoro-1-propanol and 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-1-heptanol as solvents at 50 and 130°C., respectively. Endgroup determinations on samples were also done in m-cresol by 0.1 N-hydrochloric acid. Reduced resistance differences (ΔR/C)₀ obtained by vapor pressure osmometry at 50°C. were found to be in linear relation with the reciprocal of the number-average molecular weight determined by endgroup titrations; but anomalous results were obtained when dodecafluoroheptanol was used as the solvent at 130°C.     

Crystalline transformation of native cellulose from cellulose I to cellulose ID polymorph by a ball-milling method with a specific amount of water

We have demonstrated for the first time that a mechano-chemical treatment of native cellulose with a specific amount of water (30 wt%) present ID the cellulose solid state caused the crystalline transformation from cellulose I into cellulose ID polymorph. X-ray diffractometry was used to show that the extent of transformation into cellulose ID increased with milling time. This specific phenomenon can be explained by considering the chain mobility ID the cellulose–water system, because ₁ ^1H measurement shows that cellulose molecules are most mobile when the water content ID around 30 wt%, and thus are favorable for molecular rearrangement under external forces.     

Thermal reaction of β-carotene: Part 2. Pyrolysis in the presence of kaolinite

β-Carotene was heated with a clay mineral (kaolinite) under vacuum at temperatures ranging from 200 to 350°C for 24 h. Several polymethylbenzenes, naphthalenes and probably phenanthrenes were observed in the pyrolysate at 350°C. Furthermore, ionene, some polymethylbenzenes and a dimethylnaphthalene were detected at temperatures between 200 and 250°C. It was concluded that the clay mineral may act as an acidic catalyst.     

Gluco-indole alkaloids from Nauclea cadamba in Thailand and transformation of 3 alpha-dihydrocadambine into the indolopyridine alkaloid, 16-carbomethoxynaufoline

Three monoterpenoid gluco-indole alkaloids, 3beta-isodihydrocadambine, cadambine, and 3alpha-dihydrocadambine, were isolated from Nauclea cadamba ROXB. growing in Thailand. The stereochemistry at C19 in 3beta-isodihydrocadambine was elucidated to be R by spectroscopic analysis. Treatment of 3alpha-dihydrocadambine with beta-glucosidase in aqueous ammonium acetate solution gave an indolopyridine alkaloid, 16-carbomethoxynaufoline, and an unusually rearranged compound.     

Vertical distributions of global fallout 137Cs and 14C in a Japanese forest soil profile and their implications for the fate and migration processes of Fukushima-derived 137Cs

Vertical distributions of global fallout ¹³⁷Cs and ¹⁴C were investigated in a Japanese forest soil in 2001. Even 38 years after the fallout, ¹³⁷Cs was still observed mostly in the uppermost 5 cm. A preferential accumulation of ¹³⁷Cs was found in a 1-cm-thick transition layer between organic-rich A and underlying B horizons. This unique observation indicated that ¹³⁷Cs migrated through the A horizon at a rate of 0.20 % year⁻¹ and the transition layer acted as a barrier for ¹³⁷Cs migration to deeper layers. The vertical distributions of ¹³⁷Cs and ¹⁴C were significantly correlated, suggesting a coupled downward migration of ¹³⁷Cs and organic matter on a time scale of decades, along the same physical pathways.