Nitrogen release from polyolefin-coated urea with attention to individual weights

Nitrogen release from individual granules of polyolefin-coated urea (POCU) was studied in order to evaluate a variation in N release. Individual granules were immersed in 10 ml water at 25°C for 7 and 20 d. Individual granules of POCU had different weights and N release rates. An increase in the individual weights of POCU led to a decrease in the N release for both incubation periods. This relationship between the N release and individual weights may be related to the coating thickness.     

Mode of action of (1'S,2'R)-9-[[1',2'-bis(hydroxymethyl) cycloprop-1'-yl]methyl]guanine (A-5021) against herpes simplex virus type 1 and type 2 and varicella-zoster virus

The mode of action of (1'S,2'R)-9-([1', 2'-bis(hydroxymethyl)cycloprop-1'-yl]methyl)guanine (A-5021) against herpes simplex virus type 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV) was studied. A-5021 was monophosphorylated at the 2' site by viral thymidine kinases (TKs). The 50% inhibitory values for thymidine phosphorylation of A-5021 by HSV-1 TK and HSV-2 TK were comparable to those for penciclovir (PCV) and lower than those for acyclovir (ACV). Of these three agents, A-5021 inhibited VZV TK most efficiently. A-5021 was phosphorylated to a mono-, di-, and triphosphate in MRC-5 cells infected with HSV-1, HSV-2, and VZV. A-5021 triphosphate accumulated more than ACV triphosphate but less than PCV triphosphate in MRC-5 cells infected with HSV-1 or VZV, whereas HSV-2-infected MRC-5 cells had comparable levels of A-5021 and ACV triphosphates. The intracellular half-life of A-5021 triphosphate was considerably longer than that of ACV triphosphate and shorter than that of PCV triphosphate. A-5021 triphosphate competitively inhibited HSV DNA polymerases with respect to dGTP. Inhibition was strongest with ACV triphosphate, followed by A-5021 triphosphate and then (R,S)-PCV triphosphate. A DNA chain elongation experiment revealed that A-5021 triphosphate was incorporated into DNA instead of dGTP and terminated elongation, although limited chain extension was observed. Thus, the strong antiviral activity of A-5021 appears to depend on a more rapid and stable accumulation of its triphosphate in infected cells than that of ACV and on stronger inhibition of viral DNA polymerase by its triphosphate than that of PCV.     

Role of dimerization of the membrane-associated growth factor kit ligand in juxtacrine signaling: the Sl17H mutation affects dimerization and stability-phenotypes in hematopoiesis

The Kit ligand (KL)/Kit receptor pair functions in hematopoiesis, gametogenesis, and melanogenesis. KL is encoded at the murine steel (Sl) locus and encodes a membrane growth factor which may be proteolytically processed to produce soluble KL. The membrane-associated form of KL is critical in mediating Kit function in vivo. Evidence for a role of cytoplasmic domain sequences of KL comes from the Sl17H mutation, a splice site mutation that replaces the cytoplasmic domain with extraneous amino acids. Using deletion mutants and the Sl17H allele, we have investigated the role of the cytoplasmic domain sequences of KL in biosynthetic processing and cell surface presentation. The normal KL protein products are processed for cell surface expression, where they form dimers. Both Sl17H and the cytoplasmic deletion mutants of KL were processed to the cell surface; however, the rate of transport and protein stability were affected by the mutations. Deletion of cytoplasmic domain sequences of KL did not affect dimerization of KL. In contrast, dimerization of the Sl17H protein was reduced substantially. In addition, we have characterized the hematopoietic cell compartment in Sl17H mutant mice. The Sl17H mutation has only minor effects on hematopoiesis. Tissue and peritoneal mast cell numbers were reduced in mutant mice as well as in myeloid progenitors. Interestingly, long-term bone marrow cultures from Sl17H mice did not sustain the long-term production of hematopoietic cells. In addition, homing of normal hematopoietic progenitors to the spleen of irradiated Sl17H/Sl17H recipient mice was diminished in transplantation experiments, providing evidence for a role of Kit in homing or lodging. These results demonstrate that the membrane forms of KL exist as homodimers on the cell surface and that dimerization may play an important role in KL/Kit-mediated juxtacrine signaling.     

Highly reliable 60/spl deg/C 50-mW operation of 650-nm band window-mirror laser diodes

High-power GaInP QW laser diodes with a window-mirror-structure lasing at a wavelength of around 650 nm have been fabricated. The maximum light output power over 150 mW has been realized without optical mirror damage. In addition, the laser shows the fundamental-mode-operation at 50 mW and the dynamic characteristics sufficient for recordable digital versatile disc (DVD) applications. The lasers have been operating for 2000 h under the condition of CW, 50 mW, and 60/spl deg/C, for the first time.     

TCI temperamental scores in bulimia nervosa patients and normal women with and without diet experiences

The tailspike protein (TSP) of bacteriophage P22 is a homotrimeric multifunctional protein responsible for cell attachment and hydrolysis of the Salmonella typhimurium host cell receptor. Despite the folding of TSP involves the formation of thermolabile intermediates, the mature protein is extremely resistant to heat and detergent denaturation. We have analyzed the thermal resistance and unfolding pathway of two mutant, functional TSPs carrying end-terminal peptide fusions. Whereas the C-terminal fusion has minor effects on the TSP stability, the presence of a 23-mer foreign peptide at the N terminus (protein ATSP) results in a significant enhancement of the thermal resistance by retarding the first transition step of the unfolding process. At 65 degrees C and in 2% SDS, the unfolding rate constant for the transition from the native to the unfolding intermediate is 9.3 x 10(-4) s(-1) for ATSP versus 1.7 x 10(-3) s(-1) for wild-type TSP. On the other hand, the electrophoretic mobility of ATSP intermediates is greatly affected, proving structural modifications induced by the fused peptide. These results suggest a critical participation of the N-terminal domain in the unfolding kinetic barriers generated during the TSP denaturation pathway.     

Thoracic surgery and liver dysfunction

Lung resection results in loss of lung parenchyma including residual healthy lung tissue and in reduction in pulmonary vascular bed. A decrease in residual pulmonary vascular bed after lung resection causes an increase in right heart afterload, and in some patients, it would be associated with an increase in right heart preload and consequent the changes in hepatic circulation which would lead to liver damage. Preceding thoracotomy, unilateral pulmonary arterial occlusion test (UPAO) was performed to simulate the hemodynamic changes after lung resection to evaluate the increase in right heart preload after surgery. Patients with the decreases in cardiac index or PaO2 during UPAO showed a higher levels of GPT during postoperative period when compared with those with the increase in either parameters. In a surgical treatment for empyema, bronchiectasis, or other infectious lung diseases, bronchial angiography (BAG) and also bronchial arterial embolization (BAE) were useful methods to prevent from exceeding bleeding during thoracotomy, which is one of the risk factors to cause liver damage after surgery. These results suggest that, in the field of thoracic surgery, the preoperative assessment of the hemodynamic changes caused by lung resection and the preoperative attempt to prevent from bleeding during thoracotomy are both important to protect from liver damage caused by surgical stress.     

Histopathological studies of senile plaques and cerebral amyloidosis in cynomolgus monkeys

Senile plaques (SPs) and cerebral amyloid angiopathy (CAA), pathological hallmarks of Alzheimer's disease, have not been thoroughly investigated histopathologically in nonhuman primates. To determine the onset age and histopathological characteristics of SPs and CAA, we examined the brains of 64 cynomolgus monkeys (Macaca fascicularis) from 2 to 35 years old. Mature (classical and primitive) plaques appeared in 16 out of 25 monkeys that were >20 years old. Moreover, mature plaques were observed more frequently than diffuse plaques and were located in the temporal cortex of the superior or inferior gyri and amygdala. Diffuse plaques in contrast to mature plaques did not show definite tendencies in onset age and distribution. CAA appeared in more than 22-year-old monkeys in 10 out of 16 animals and was frequently observed in capillaries and often found adjoining mature plaques. During immunohistochemical examination, an antiserum for amyloid beta protein (A beta) 1-40 could detect all SPs, whereas a monoclonal antibody for A beta 8-17 could not detect any diffuse plaques and only one third of the primitive plaques. As for CAA, the polyclonal antiserum was more sensitive than the monoclonal antibody. The present study describes the histopathological features of SPs and CAA in old cynomolgus monkeys.     

Leonardo's constraint: Two opaque objects cannot be seen in the same direction.

Given Leonardo's constraint that 2 opaque objects cannot be seen in the same direction, how are the regions of objects occluded to 1 eye included in perception? To answer this question, the authors presented 3-dimensional stimuli, similar to the ones that concerned Leonardo, and measured the visual directions of their monocular and binocular regions. When the distance between near and far objects was large, the nonfixated object was seen as double and blurry. Leonardo's constraint was met by seeing the near object as double and transparent or the distant object as double and superimposed. When the distance between near and far objects was small, the constraint was met by a perceptual displacement and compression of parts of the nonfixated object. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Calciothermic reduction of titanium oxide and <Emphasis Type="Italic">in-situ</Emphasis> electrolysis in molten CaCl<Subscript>2</Subscript>

A concept for calciothermic direct reduction of titanium dioxide in molten CaCl₂ is proposed and experimentally tested. This production process consists of a single cell, where both the thermochemical reaction of the calciothermic reduction and the electrochemical reaction for recovery of the reducing agent, Ca, coexist in the same molten CaCl₂ bath. A few molar percentages of Ca dissolve in the melt, which gives the media a strong reducing power. Using a carbon anode and a Ti basket-type cathode in which anatase-type TiO₂ powder was filled, a metallic titanium sponge containing 2000 ppm oxygen was produced after 10.8 ks at 1173 K in the CaCl₂ bath. The optimum concentration of CaO in the molten CaCl₂ was 0.5 to 1 mol pct, to shorten the operating time and to achieve a lower oxygen content in Ti.     

Vascular invasion of O-1N, hamster squamous cell carcinoma with high potential of lymph node metastasis: ultrastructural comparison between lymphatics and blood vessels

The ultrastructural modes of lymphatic and blood vessel invasions were studied comparatively in hamsters with squamous cell carcinoma (O-1N) that had a high potential for lymph node metastasis. The endothelial injury, which was caused by mechanical stretching with the growth of O-1N, was the initial and characteristic feature common to both vascular invasions. Tumor cell nests penetrating the lymphatic lumen through disrupted endothelial cells still maintained their volume and continuity to the underlying tumor cell nests. In contrast, pronounced microthrombotic and neutrophilic reactions occurred at the site of blood vessel penetration. Within the lymphatic lumen, large clusters of O-1N cells were kept longer in spite of lymphocytic and macrophagic reactions. In blood vessels, clusters of tumor cells that had passed through dense fibrin layers were reduced in size and further disintegrated into smaller pieces by neutrophils. In conclusion, lymphatic invasion is a mechanical process, and smooth and direct invasion of large tumor cell nests into lymphatic vessels is responsible for causing more prompt and frequent lymph node metastasis in O-1N than a hematogenous type.