Radiation-induced bystander effects induce radioadaptive response by low-dose radiation

When normal human fibroblast cells (MRC-5) received a priming irradiation of 3-20 mGy 4 h prior to irradiation with 1000 mGy, the number of DNA double-stranded breaks (DSBs) decreased significantly to 18.2-18.7 per cell compared with 21 per cell when there was no priming irradiation. This result indicates that a priming irradiation of 3-20 mGy induces a radioadaptive response in MRC-5. The authors' previous study had indicated that DSBs induced by ≤ 20 mGy are due to a radiation-induced bystander effect. These findings suggest that radiation-induced bystander effects might contribute to induction of the radioadaptive response. To test this hypothesis, MRC-5 were suspended in lindane, an inhibitor of radiation-induced bystander effects, which was added to the medium for the priming irradiation of 3-20 mGy. Lindane inhibited the protective effect of priming irradiation on DSBs caused by subsequent irradiation with 1000 mGy. Thus, radiation-induced bystander effects may play a role in radioadaptive responses.     

Assimilative and co-metabolic degradation of chloral hydrate by bacteria and their bioremediation potential

Although the bacterial degradation of chloral hydrate (CH) has been recognized for several decades, its degradation pathway by assimilation has not been demonstrated. In this paper, we report the isolation of the LF54 bacterial strain, which utilizes CH as its sole carbon and energy source. LF54 converted CH into trichloroethanol (TCAol), which was dehalogenated to dichloroethanol (DCAol), and CO(2) was detected as the end product. Another strain that we isolated, RS20, co-metabolized CH into TCAol. Our 16S rRNA gene sequencing and taxonomic analyses revealed that the LF54 and RS20 strains belong to the Pseudomonas and Arthrobacter genera, respectively. When the two strains were inoculated into soil microcosms, both degraded 0.3mM CH to undetectable levels (<0.01mM) within 5days. These results suggest that LF54 and RS20 could be used in the bioremediation of CH-contaminated environments.     

Interplay Between Vorticity and Chirality Inside the Vortex Core in Chiral p-Wave Superconductors

The vortex core in chiral p-wave superconductors exhibits various properties owing to the interplay between the vorticity and chirality inside the vortex core. In the chiral p-wave superconductors, the site-selective nuclear spin-lattice relaxation rate T ^–1 ₁ is theoretically studied inside the vortex core within the framework of the quasiclassical theory of superconductivity. T ^–1 ₁ at the vortex center depends on the sense of the chirality relative to the sense of the magnetic field. The effect of a tilt of the magnetic field upon T ^–1 ₁ is investigated. The effect of the anisotropy in the superconducting gap and the Fermi surface is then investigated. The result is expected to be experimentally observed as a sign of the chiral pairing state in a superconducting material Sr₂RuO₄.     

Administration of rhG-CSF increases complete remission rates after CHOP and ProMACE/CytaBOM for non-Hodgkin's lymphoma: a pilot study. Hokkaido Study Group of Malignant Lymphoma and rhG-CSF

To evaluate the clinical effects of the administration of recombinant human granulocyte-stimulating factor (rhG-CSF) post chemotherapy for patients with advanced-staged intermediate-grade or high-grade non-Hodgkin's malignant lymphoma (NHL), we conducted this multicenter study and compared the responses between both the regimens, CHOP as a first-generation chemotherapy and ProMACE/CytaBOM as a third-generation chemotherapy, when combined with the rhG-CSF administration. In this multicenter study, where forty patients were registered, patients in both the CHOP and ProMACE/CytaBOM groups were treated with the original regimen designs without the necessity of reducing drug dosages when combined with the administration of rhG-CSF. The administration of rhG-CSF post both of the cytotoxic therapies brought about much higher rates of complete remission in both the groups (CHOP, 75 percent; ProMACE/CytaBOM, 75 percent), as compared with those of the previous study without the rhG-CSF administration. Regarding response rates according to the International prognostic factor index, the CHOP group showed a lower rate of complete remission in patients with risk factors, compared with ProMACE/CytaBOM group. This result suggested that the administration of rhG-CSF may offer one important approach for improving the first-line therapy for aggressive NHL with high risk factors.     

Transformation of skin from larval to adult types in normally metamorphosing and metamorphosis-arrested salamander, Hynobius retardatus

Transformation of skin from larval to adult types in a salamander, Hynobius retardatus, which had been reported to show neotenic reproduction in a specific environment, was examined morphologically in normally metamorphosing, precociously metamorphosing and metamorphosis-arrested larvae. Typical larval skin was composed of an epidermis constituted by three types of cells such as apical, Leydig, and basal cells. The Leydig cells were larval specific, and thus disappeared and were replaced by adult epidermal cells during the metamorphosis. Disappearance of the Leydig cells was accomplished by apoptosis as confirmed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end-labeling method and electron microscopy during the normal metamorphosis and precocious metamorphosis induced by exogenously applied triiodothyronine. Typical adult skin was composed of epidermis constituted by stratified squamous cells and of dermis mainly occupied with two types of dermal glands, mucous and serous glands. When the metamorphosis was arrested by different procedures (thyroidectomy, hypophysectomy, goitrogen treatment, and rearing at low temperature), the larval-specific Leydig cells fully remained in the epidermis, suggesting that the disappearance of these depended on the thyroid activity. Contrary to this, dermal glands behaved differently from the Leydig cells, though they developed and differentiated from epidermal basal cells and constituted the same skin. Those in the metamorphosis-arrested (thyroidectomized, hypophysectomized, or goitrogen-treated) larvae, except in the larvae reared at 4 degrees C, appeared a little later than in the controls. Thus, the aged, metamorphosis-arrested larvae had skin which consisted of larval type epidermis (Leydig cells) and adult type dermis (mucous and serous glands).     

Gas absorption into “string-of-beads” liquid flow with chemical reaction: application to carbon dioxide separation

This study examines the performance of “string-of-beads” liquid flow on vertical wires as a novel gas-liquid contact device for gas absorption using a chemically reacting liquid absorbent. The string-of-beads flow is a distinct on-wire liquid-flow pattern consisting of annular thin liquid films sheathing a wire and teardrop-shaped liquid beads alternately aligned on the wire at regular intervals. We have performed experiments of CO₂ absorption by an aqueous monoethanolamine solution in string-of-beads flow on a single wire and have developed an analytic gas-absorption model relevant to the experiments. The model well simulates the CO₂-absorption characteristics observed in the experiments, thereby suggesting the utility of the model in predicting the chemical gas-absorption performance of multiple-wire gas-liquid contactors.     

The tensile properties of an Fe-4 pct Mo-0.2 pct C martensite tempered under applied stress

In Fe-4 pct Mo-0.2 pct C martensite which is a typical secondary hardening steel, premature failure o°Curred in tensile test at 600 °C to 700°C where solute atoms could diffuse easily. To clarify this phenomenon, the quenched specimens were tempered under applied stress and tensile-tested at room temperature. The following results were obtained: (1) Typical intergranular fracture was observed in specimens tempered in a temperature range of 600 °C to 650 °C with tempering times of five minutes to 10 minutes and applied stress (70 MPa to 140 MPa). (2) Based on Auger analysis, this phenomenon was considered to be caused by segregation of P, S, and Mo on prior austenite grain boundaries due to applied stress. (3) The direction of applied stress was found to be very significant. Namely, when the tensile direction was parallel to the applied stress during tempering, the specimen was more brittle, and when tensile direction was normal to the applied stress, the specimen was not so brittle. (4) To reduce this embrittlement, solution treatment temperature was adjusted, and it was found that the embrittlement was considerably reduced both in specimens with fine prior austenite grains and with some ferrite phase on prior austenite grain boundaries. TAKATOSHI OGAWA, formerly with Kyoto University. YOSHIFUMI OHMURA, formerly with Kyoto University. This paper is based on a presentation made at the “pcter G. Winchell Symposium on Tempering of Steel” held at the Louisville Meeting of The Metallurgical Society of AIME, October 12-13, 1981, under the sponsorship of the TMS-AIME Ferrous Metallurgy and Heat Treatment Committees.     

Mortality from major causes of death and its risk factors in the elderly--26-year follow-up study in Hisayama

The authors studied mortality from major causes of death and risk factors in the elderly in a long-term prospective survey conducted in a Japanese suburban community, Hisayama. In the baseline survey in 1961, we scrutinized 1658 residents of the town aged 40 years or older accounting for 92% of the total population in this age range. Of those, 591 residents (245 men and 346 women) aged 60 years or older, who were free from major cardiovascular disease, were selected for the present study. They were followed-up for 26 years from 1961 to 1987. The average age was 67 years for men and 70 years for women, being significantly higher for women than for men. During the follow-up period, 529 subjects (89.5%) died, and 448 were autopsied (autopsy rate 84.7%). The all-cause mortality (per 1,000 person-years) after adjustment for age was 89.9 for men and 56.7 for women, the former being significantly higher than the latter (p < 0.01). The age-adjusted mortality from cerebrovascular disease was estimated to be 21.4 for men and 9.9 for women, i.e. 8.9 and 8.8 from heart disease, and 19.9 and 10.6 from neoplasm, and 18.1 and 12.2 from-pneumonia, respectively. There was significant sex difference in mortality from cerebrovascular disease, neoplasm and pneumonia (p < 0.01) but not from heart disease (p > 0.1). Multiple Cox's proportional hazards regression analysis showed systolic blood pressure and male sex to be significant risk factors for death by cerebrovascular disease. Systolic blood pressure was also a predictor for death by heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Crystallization of amorphous antimony films

Diffusion of the divalent impurities Mn²⁺, Ca²⁺, Cu²⁺, Fe²⁺, Co²⁺, Pb²⁺, Zn²⁺, Eu²⁺ and S^2- in sodium chloride and other alkali halide crystals has been studied by electron microscopy and diffraction. At temperatures in the range 100°–700°C the impurities diffuse to the surface and form oxides which in some cases are epitaxial. This distribution of the impurities on the surface is studied and is found to have a strong influence on the overgrowth of other epitaxial deposits.     

InGaAs avalanche photodiode with InP p-n junction

A new InGaAs avalanche photodiode structure that has an InGaAs light absorption region and InP avalanche multiplying region is proposed. A dark-current density of 2.2 × 10?3 A/cm2 at 90% of breakdown voltage and a multiplication factor of 45 were obtained for the new structure diode fabricated from a liquid-phase epitaxially grown wafer.