Survival by Mac-1-mediated adherence and anoikis in phorbol ester-treated HL-60 cells

During the exposure of human myelocytic leukemia HL-60 cells to phorbol diester, nonadherent cells die by apoptosis, but adherent cells survive and growth-arrest at G1 phase of the cell cycle. Here we have shown that the adherent cells rapidly died by apoptosis after forced detachment (anoikis), indicating that phorbol diester induced apoptosis by default. Dimethylsphingosine induced apoptosis in the adherent cells, and sphingosine-1-phosphate rescued the detached cells from apoptosis. Sphingosine kinase activity in adherent cells was higher than that in nonadherent cells and was decreased by forced detachment. It is likely that the phorbol diester-induced apoptosis and the adhesion-mediated survival are modulated by sphingosine and sphingosine-1-phosphate, respectively. The adherent cells were reverted and reproliferated when allowed to spontaneously detach from plastic surfaces by removal of phorbol diester. This result suggests that after removal of phorbol diester, the commitment signal of apoptosis by default is lost faster than the survival signal by adherence.     

Clinical and molecular genetic study in seven Japanese families with spinocerebellar ataxia type 6

This study examined the effect of thyrotrophin-releasing hormone (TRH) administration on thermoregulation in the newborn. Twin lambs were either delivered near-term by caesarean section or born vaginally at term. Colonic temperature, O2 consumption, CO2 production, breathing and heart rates, plus plasma thyroid hormone and nonesterified fatty acid (NEFA) concentrations and thermogenic activity (i.e. GDP binding) of brown adipose tissue (BAT) were measured. In caesarean section delivered lambs colonic temperature decreased rapidly after birth, a response that was greater in the group designated for TRH treatment, in which colonic temperature fell to below 36.0 degrees C at 80 min of life, prior to TRH administration. At this age colonic temperature had been restored to a mean of 38.70 degrees C in controls. TRH had no influence on the composition or thermogenic activity of BAT. The incidence of shivering was not influenced by TRH, but treated lambs maintained a higher rate of O2 consumption and ventilation compared with controls after colonic temperature had been restored to 38.56 degrees C. TRH appeared to promote fat oxidation as O2 consumption remained unchanged and CO2 production declined by a greater rate in treated lambs, resulting in a lower respiratory quotient compared to controls. Heart rate and plasma concentrations of NEFA increased following TRH administration although this did not result in values greater than controls. Normothermic lambs born vaginally had BAT with a greater thermogenic activity, higher plasma thyroid hormone and NEFA concentrations compared with caesarean section delivered lambs, but a thermogenic response was not observed to TRH despite a rise in thyroid hormone concentrations. In conclusion, TRH can improve thermoregulation, an effect that could be linked to an increase in fat oxidation.     

Epoxyquinomicins A, B, C and D, new antibiotics from Amycolatopsis. II. Effect on type II collagen-induced arthritis in mice

The anti-arthritic effects of epoxyquinomicins on type II collagen-induced arthritis in DBA/1J mice were examined. Prophylactic treatment with epoxyquinomicins A, B, C and D (1-4 mg/kg) had potent inhibitory effects on type II collagen-induced arthritis. In contrast to nonsteroidal anti-inflammatory drugs (NSAIDs), epoxyquinomicin C (1-30 mg/kg) had neither an anti-inflammatory effect on carrageenan-induced paw edema in rats nor an analgesic effect on acetic acid-induced writhing in mice. These results suggest that the mode of action of epoxyquinomicins is different from that of NSAIDs and that epoxyquinomicins may become useful drugs for the treatment of rheumatoid arthritis.     

Dopamine receptor subtypes expressed in vertebrate (carp and eel) retinae: cloning, sequencing and comparison of five D1-like and three D2-like receptors

Eight dopamine receptor-like cDNA clones were isolated from the carp (Cyprinus carpio) retina and four dopamine receptor-like cDNA clones were isolated from the European eel (Anguilla anguilla) retina. These cDNA clones show high sequence and structural homology to the known dopamine receptor subtypes. The sequence similarity and phylogenetic analysis revealed that five subtypes (D1A3, D1A4, D1B, D1C and D1X) in the carp retina and four subtypes (D1A1, D1A2, D1B and D1C) in the eel retina are D1-like receptor subtypes, and three (D2, D4A and D4B) in the carp retina are D2-like receptor subtypes; no D2-like receptor was found in the eel. Carp D1A3 and D1A4, carp D4A and D4B, and eel D1A1 and D1A2 are highly homologous pairs of receptors which show significant, domain-specific differences to each other and to their species homologues. The structure of the third cytoplasmic loop in the carp D1X receptor was particularly different from the other D1-like receptors. The implications of these structural differences in terms of dopamine receptor activation and signalling are discussed. It is suggested that the known diverse physiological and pharmacological effects of dopamine on the retinal neurones are likely to be mediated through these multiple receptor subtypes which may be coupled to different signal transduction pathways.     

Hydrothermal crystal growth of perovskite-type fluorides

Single crystals of perovskite-type fluorides were grown from potassium fluoride and di-valent metal chloride solutions by a hydrothermal method under a temperature gradient, at maximum temperature 600° C and pressure 98 MPa. Single-crystal cubes of KMnF₃, KFeF₃, KCoF₃ and KZnF₃, of cube edge sizes ranging from 0.2 to 2.0 mm, were grown. Crystals of KNiF₃ grew in rectangular prisms and those of KCdF₃ in anhedral form. Single crystals of KCuF₃ were grown in pure water from co-precipitated KCuF₃ powder. KMgF₃ crystals were not grown by this method.     

Preparation and Properties of Bi4 − x Nd x Ti3O12 Thin Films by Chemical Solution Deposition

Neodymium-modified Bi₄Ti₃O₁₂, (Bi, Nd)₄Ti₃O₁₂ (BNT) ferroelectric thin films have been prepared on Pt/TiO_x/SiO₂/Si substrates using metal-organic precursor solutions by the chemical solution deposition method. The BNT precursor films crystallized into the Bi layered perovskite Bi₄Ti₃O₁₂ (BIT) as a single-phase above 600C. The synthesized BNT films revealed a random orientation having a strong 117 reflection, whereas non-substituted BIT thin films exhibited a random orientation with strong 00l diffractions. Among Bi_{4 – x}Nd_xTi₃O₁₂ [x = 0.0, 0.5, 0.75, 1.0] thin films, Bi_3.25Nd_0.75Ti₃O₁₂ thin films showed a well-saturated P-E hysteresis loop with the highest P_r (22 C/cm²) and a low E_c (69 kV/cm) at an applied voltage of 5 V. The Nd-substitution with the optimum amount for the Bi site in the BIT structure was effective not only for promoting the 117 preferred orientation but also for improving the microstructure and ferroelectric properties of the resultant films.     

Characteristics of chlorophyll formation of the aerial microalga Coelastrella striolata var. multistriata and its application for environmental biomonitoring

The growth and ammonium uptake of the aerial microalga Coelastrella striolata var. multistriata, which was isolated from the surface of rocks, were characterized in this study. The specific growth rate of the alga was mu=0.3 d(-1), as calculated in the growth logarithmic phase. The algal cells were able to remove almost 100% of the ammonium ions from medium in 5 d, with the removal rate of ammonium-N being 0.4 mg/l/h. It was shown that the alga has a unique ability to be a reddish orange to green color depending on the nitrogen source concentration in the medium. Astaxanthin, adonixanthin, canthaxanthin, and beta-carotene were found in the reddish orange cells of the alga. The assessment of water pollution was attempted using this aerial microalga. When the reddish orange alga was incubated in the experimental medium with added ammonium-, nitrate-, or urea-N as a nitrogen source, an approximately linear relationship existed between the nitrogen concentration and chlorophyll formation. Using the chlorophyll formation of the alga, for example, it was possible to estimate spectrophotometrically the total nitrogen content in water collected from aquatic systems. Biofunctional materials for environmental biomonitoring using photosynthetic microorganisms are called green devices in this study.     

Two-dimensional multiarray formation of hepatocyte spheroids on a microfabricated PEG-brush surface

A two-dimensional microarray of ten thousand (100 x 100) hepatocyte heterospheroids, underlaid with endothelial cells, was successfully constructed with 100 microm spacing in an active area of 20 x 20 mm on microfabricated glass substrates that were coated with poly(ethylene glycol) brushes. Cocultivation of hepatocytes with endothelial cells was essential to stabilize hepatocyte viability and liver-specific functions, allowing us to obtain hepatocyte spheroids with a diameter of 100 microm, functioning as a miniaturized liver to secret albumin for at least one month. The most important feature of this study is that these substrates are defined to provide an unprecedented control of substrate properties for modulating cell behavior, employing both surface engineering and synthetic polymer chemistry. The spheroid array constructed here is highly useful as a platform of tissue and cell-based biosensors and detects a wide variety of clinically, pharmacologically, and toxicologically active compounds through a cellular physiological response.