Structure and surface properties of diaminocyclohexane plasma polymer films

Plasma polymers of three isomers of diaminocyclohexane (DACH) were deposited on polyethylene, SiO₂, and mica at 20°C. The deposition rate was measured as a function of plasma density and power; a maximum was observed in the latter function. The deposition rate was highest for the monomer with the highest flow rate. The film refractive index was observed to increase with both power density and the degree of fragmentation in the plasma. Film composition was measured by elementary analysis, and was found to be almost identical for each of the three isomers; a mechanism for the polymerization reaction is proposed. The percentage of primary amino groups decreased with increasing power density and with film thickness. Surface force measurements of the thickness and refractive index agreed well with the corresponding ellipsometry values in dry air, and am adhesive force, independent of power density, was measured. When the film was exposed to water vapor, it swelled considerably and the adhesion was determined by capillary forces. Associated with swelling, at high power, was an extremely regular 2-ply rope pattern of protruding material. © 1993 John Wiley & Sons. Inc.     

Continuously distributed phase shifts in chirped DFB lasers usingbent waveguides

The authors have implemented chirped distributed feedback (DFB) grating lasers with phase shifts [λ/8, 2λ/8 and 3λ/8] distributed continuously over various axial distances, using their recently proposed method for producing bent optical waveguides. The singlemode stability of the lasers with distributed phase shifts was found to be considerably higher than for lasers with abrupt phase shifts     

Mechanism of the early stages of α1 plate formation in a Cu-39 Pct Zn alloy

The early stages in the formation of α₁ plates in the ordered β′ matrix of a Cu-39 pct Zn alloy have been studied with transmission electron microscopy (TEM). The early stage plates were found to be free of stacking faults. Their contrast features are indeed those normally expected from small coherent plates. Electron microdiffraction confirms that these plates have the 9R structure characteristic of α₁ with the same lattice parameters and orientation relationships reported by previous investigators at much later stages of growth. Similarly, the 9R structure was disordered, even though it was formed in an ordered matrix, again repeating previous results obtained at a later stage of growth. These results further support the view that the α₁ Cu-Zn plates form by a diffusion-controlled mechanism. This article is based on a presentation made at the Pacific Rim Conference on the “Roles of Shear and Diffusion in the Formation of Plate-Shaped Transformation Products,” held December 18-22, 1992, in Kona, Hawaii, under the auspices of ASM INTERNATIONAL’S Phase Transformations Committee.     

Sequestration of muscarinic acetylcholine receptor m2 subtypes. Facilitation by G protein-coupled receptor kinase (GRK2) and attenuation by a dominant-negative mutant of GRK2

Sequestration of m2 receptors (muscarinic acetylcholine receptor m2 subtypes), which was assessed as loss of N-[3H]methylscopolamine ([3H]NMS) binding activity from the cell surface, was examined in COS 7 and BHK-21 cells that had been transfected with expression vectors encoding the m2 receptor and, independently, vectors encoding a G protein-coupled receptor kinase (GRK2) (beta-adrenergic receptor kinase 1) or a GRK2 dominant-negative mutant (DN-GRK2). The sequestration of m2 receptors became apparent when the cells were treated with 10(-5) M or higher concentrations of carbamylcholine. In this case, approximately 40% or 20-25% of the [3H]NMS binding sites on COS 7 or BHK-21 cells, respectively, were sequestered with a half-life of 15-25 min. In cells in which GRK2 was also expressed, the sequestration became apparent in the presence of 10(-7) M carbamylcholine. Approximately 40% of the [3H]NMS binding sites on both COS 7 and BHK-21 cells were sequestered in the presence of 10(-6) M or higher concentrations of carbamylcholine. When DN-GRK2 was expressed in COS 7 cells, the proportion of [3H]NMS binding sites sequestered in the presence of 10(-5) M or higher concentrations of carbamylcholine was reduced to 20-30%. These results indicate that the phosphorylation of m2 receptors by GRK2 facilitates their sequestration. These results are in contrast with the absence of a correlation between sequestration and the phosphorylation of beta-adrenergic receptors by the GRK2 and suggests that the consequences of phosphorylation by GRK2 are different for different receptors.     

Our new fragile world doesn't consist of developed and developing countries only

Health conditions have improved worldwide; therefore, the division into developed and developing countries no longer holds true. International organizations tend to divide countries into three groups. An increasing number of people are born in middle income countries where health conditions continue to improve. However, in a number of the least developed countries, mortality is on the rise in a spiral of economic stagnation, environmental problems, social misery, and ethnic/civil conflicts. This requires the medical assistance of international agencies from abroad. Since the 1960s there has been a drastic decline of child mortality in developing countries, especially in Asia. 1 billion people live in countries with child mortality under 20/1000, almost 3 billion live in countries with child mortality ranging 20-100/1000, and over 1 billion live in the least developed countries with child mortality over 100/1000. Unicef divides countries into developed, developing, and least developed countries, while the World Bank groups them as high-, medium-, and low-income countries. Thailand's child mortality is the same as that of Russia, while Cuba has a lower rate than Washington, D.C. On the other hand, Singapore is a developed high-income country with one of the world's healthiest populations. Stagnation and conflicts in the former socialist countries mean that many Asian and Latin American countries have better health status than some parts of Europe. Despite Africa's high mortality, its population growth is the highest in the world: in 20 years its population has doubled. Economic stagnation and the debt burden in many of these countries has resulted in ethnic conflicts and the collapse of social institutions: Somalia, southern Sudan, Rwanda, Liberia, Angola, perhaps Zaire, and Mozambique. The organization Physicians Beyond Borders is an example of extending humanitarian help and combatting social collapse in the least developed countries.     

Interleukin-6 cDNA transfected Lewis lung carcinoma cells show unaltered net tumour growth rate but cause weight loss and shortened survival in syngeneic mice

HuIL-6 cDNA, cloned into a neomycin resistant conferring expression vector, BMGNeo, was transfected into Lewis Lung Carcinoma (LLC) cells. LLC cells (5 x 10(6) ml-1) transfected with IL-6 cDNA (LLC-IL6) secreted IL-6 into the culture supernatant at a concentration of 9.9 ng ml-1 within 48 h. When 1,000,000 of untransfected LLC, BMGNeo vector transfected LLC (LLC-Neo) or LLC-IL6 cells were transplanted into C57BL/6 mice subcutaneously, the mean +/- s.d. of survival times of these mice were 33.3 +/- 9.7, 34.3 +/- 7.1 and 17.0 +/- 3.1 days, respectively. The survival time of LLC-IL6 cells transplanted mice was significantly shorter than that of LLC (P < 0.01) or LLC-Neo (P < 0.01) cells transplanted mice without a measurable difference of tumour size. Plasma concentration of IL-6 steadily increased in LLC-IL6 transplanted mice. Body weight and serum albumin were significantly lower in LLC-IL6 transplanted mice than in LLC transplanted mice. Mouse IL-1 alpha and mouse TNF-alpha were not detected in the plasma of LLC-IL6 transplanted mice. These data suggested that secretion of IL-6 from LLC cells was unable to alter net tumour growth rate but rather caused a state similar to cachexia without detectable increase of IL-1 alpha and TNF-alpha in the plasma. This state may be responsible for the shortened survival of LLC-IL6 tumour-bearing mice.     

A case of venous aneurysm

A 70-year-old woman was referred to our hospital with a complaint of a soft mass at the right elbow. Venography demonstrated that the mass was connected with vein. This mass was surgically removed and histologically a marked reduction of both elastic fibers and the adventitia were observed in the aneurysmal wall. Venous aneurysm (VA) is different form varicose veins by many features. It was considered that congenital fragility of the venous walls was associated with the onset of VA. We classified VA into type-I VA (cystic ectasia) and type II (fusiform ectasia).     

Morphological and functional polymorphism within clonal thyroid nodules

Thirty-nine thyroid nodules, removed because of recent growth, were analyzed morphologically by serial histological sections for the classical histomorphological hallmarks of follicular cell replication and for immunohistochemically demonstrable overexpression of the growth-associated ras-gene product p21ras. Clonal analysis was performed using the highly informative probe M27 beta that detects polymorphisms on the locus DXS255 of the X-chromosome. Twenty-four nodules were of clonal and 15 nodules were of poly-clonal origin. Only 3 out of the 24 clonal nodules were histomorphologically uniform. In all others, the structural hallmarks of active growth and the P21ras growth-marker expression were remarkably heterogeneous throughout the tumors. There were no histomorphological characteristics distinguishing these clonal tumors from polyclonal nodules. Even if a clonal thyroid tumor may be originally homogeneous in respect to the parameters studied here, mechanisms must exist that create wide heterogeneity of growth and of morphogenetic potential among the individual follicular cells during further expansion of the nodule. Thus, clonal nodules are much more common in nodular goiters than hitherto assumed on grounds of the classical morphological criteria. The diagnosis of a true monoclonal nodule can no longer rely on morphological and functional criteria alone but requires molecular or cytogenetic analysis of clonality.     

The potato mitochondrial initiator methionine tRNA gene and its flanking regions: an illustration of the diversity of mitochondrial genome rearrangements among plant species

The initiator methionine transfer RNA (tRNA(fMet)) gene was identified on a 347 bp Eco RI-Hind III DNA fragment of the potato mitochondrial (mt) genome. The sequence of this gene shows 1 to 7 nucleotide differences with the other plant mt tRNAs(fMet) or tRNA(fMet) genes studied so far. Whereas the tRNA(fMet) gene is present as a single copy in the potato mt genome, a tRNA 'pseudogene' corresponding to 60% of a complete tRNA (from the 5' end to the variable region) and located at 105 nucleotides upstream of the tRNA(fMet) gene on the opposite strand was shown to be repeated at least three times. Furthermore, the physical environment of the tRNA(fMet) gene in the mt genome is very different among plants, which suggests that the tRNA(fMet) gene region has often been implicated in recombination events of plant mt genomes leading to important rearrangements in gene order.     

Drug therapy of hemiballism. Review of the literature and personal observations

Hemiballism is a rare hyperkinetic disorder which is characterized by irregular vigorous rotatory movements of the limbs of one side of the body. The disabling and exhausting movements with their high risk of severe injuries require an acute drug treatment. However, there are no common guidelines for the treatment of this disorder. Therefore we reviewed the available literature to establish a concept for a rational symptomatic drug treatment. Furthermore, own observations in 6 patients with hemiballism of different origins are reported.