The ultrastructure of human endometrium is altered by administration of intrauterine levonorgestrel

We studied the effect of intrauterine administration of levonorgestrel (LNG) on the ultrastructure of the endometrium. Twenty-one endometrial biopsy specimens, collected from nine fertile women during normal menstrual cycles and after 1, 3 or 6 months of use of a levonorgestrel-releasing intrauterine contraceptive system (LNG IUS), were studied using transmission and scanning electron microscopy. During the 6 month exposure to LNG IUS, changes took place in the endometrium. The glandular epithelial cells became lower. The junctional complexes between epithelial cells remained unchanged, whereas the lateral microvillar interdigitations became more prominent. The basal lamina under the epithelium became wavy but remained uniform and practically uninterrupted; only solitary epithelial cell protrusions through the basal lamina were seen. The stromal cells were largely decidualized. We conclude that in parallel with the generally known cellular effects, the use of the LNG IUS results in distinct changes in the basal lamina between the endometrial epithelial and stromal cells. The especially well-developed and uninterrupted basal lamina may be involved in the mechanism of the LNG IUS-induced endometrial suppression. Furthermore, the complex intercellular junctions between the epithelial cells, normally loosening around the time of implantation, persist during the local administration of levonorgestrel. This may have a pivotal role in the contraceptive effect of the LNG IUS.     

Inferior vena caval filters: an overview of current use

MTX-induced hepatic injury and liver enzyme elevations have been demonstrated after treatment of leukemia, gestational disease and during treatment of psoriasis and rheumatoid arthritis. A 40-year-old man with a long standing history of rheumatoid arthritis was treated with MTX over a 6 month period and developed an overwhelming hepatic necrosis. He was successfully transplanted.     

Glutathione metabolism and glutathione S-conjugate export ATPase (MRP1/GS-X pump) activity in cancer. II. Cell-to-cell variability, relation with cellular activation state and functional absence of GS-X pump in lymphocytes

A severe complication in late-stage cancer patients is host immunosuppression. It is suggested that overproduction of the highly cytostatic and cytotoxic antiproliferative cyclopentenone prostaglandins (CP-PGs) within the plasma of cancer-bearing subjects may contribute to immunosuppression. Lymphoid tissues of Walker 256 tumor-bearing rats accumulate large amounts of CP-PGs while the tumor tissue itself does not. Moreover, tumor cells may present differential sensitivity to CP-PGs due to the expression of the multidrug resistance-associated protein (MRP1) gene product which shows a Mg(2+)-dependent vanadate-sensitive glutathione S-conjugate export ATPase (GS-X pump) activity that extrudes CP-PGs from cells as glutathione S-conjugates. In this study, the possibility that deficient GS-X pump activity in immune cells that may be involved in the accumulation of CP-PGs is investigated. Rat lymph node lymphocytes do not exhibit any notable activity even when mitogen-stimulated. Conversely, although rat peritoneal resident (quiescent) or thioglycollate-stimulated (inflammatory) macrophages exhibit low GS-X pump activity, Bacillus Calmette-Guérin (BCG)-activated macrophages show a notable rise in the activity of the ATPase, suggesting that the cellular activation state may modulate GS-X pump activity/expression and that, under appropriate stimuli (e.g., during immune response) macrophages may provide a self-defense against electrophilic CP-PGs by forming GS-conjugates that can be extruded from cells through the GS-X pump. ras oncogene expression may be linked with MRP1/GS-X pump expression/activity, since C2C12 promyoblasts transformed by v-H-ras transfection doubled GS-X pump activity. These results support the proposition that the accumulation of CP-PGs and the immunosuppression of tumor-bearing subjects may be attributed to a lack of GS-X pump activity/expression in lymphocytes.     

Absolute copy number and relative change in determinations of human immunodeficiency virus type 1 RNA in plasma: effect of an external standard on kit comparisons

Use of a common set of human immunodeficiency virus type 1 (HIV-1) RNA standards eliminated differences among absolute HIV-1 RNA copy number estimates made with three commercially available assays. The relative changes in the viral RNA levels determined by the commercial assays were similar and were unaffected by the use of a common set of standards.     

SN388大线快速测试器电路分析及改造

法国赛舍尔公司生产的ＳＮ３８８遥测地震仪，配套的大线快速测试器用于检测野外生产中采集大线的４８Ｖ电源电压及５Ｖ加电信号，可帮助判断和排除排列故障。但该产品无电原理图，使用的某些器件又不通用，而且不能检测采集大线中的数传信号，为此在分析ＳＮ３８８大线快速测试器电路原理的基础上，开发了一种新型大线快速测试器，除保留原有测试国能外，增加了数传信号的检测及电源线的检测功能，其电路设计简单，器件通用性强，易     

单片机80C552与字符型LCD的接口应用

字符型液晶显示模块（ＬＣＤ）具有使用方便具有灵活，低耗节电，长寿命及高可靠性等优良的性能，可以广泛被用作各种智能仪器的显示部分，尤其适合于作为电池供电的便携式仪器，仪表的显示部分，文章介绍了字符型ＬＣＤ与８０Ｃ５５２的硬件接口电路和实际应用的软件编程实例。     

Genetics of methane and methanol oxidation in gram-negative methylotrophic bacteria

Within the past few years, considerable progress has been made in the understanding of the molecular genetics of methane and methanol oxidation. In order to summarize this progress and to illustrate the important genetic methods employed, this review will focus on several well-studied organisms. These organisms include the gram-negative faculative methylotrophs Methylobacterium extorquens, Methylobacterium organophilum and Paracoccus denitrificans. In addition, the obligate methanotrophs Methylococcus capsulatus and Methylosinus trichosporium are discussed. We have chosen not to discuss the genetics of methanol oxidation in the yeasts or in gram-positive bacteria. Likewise, the genetics of related topics (for example, methylamine oxidation and carbon assimilation pathways) are not reviewed here. Broad host range conjugatable plasmids have enabled researchers to complement mutations and clone genes from gram-negative methylotrophic bacteria. More recently, 'promoter probe' derivative plasmids have been used to elucidate aspects of gene regulation. Also, alternative gene-cloning techniques are proving useful in circumventing problems in the genetic studies of the obligate methanotrophs, the group of bacteria that is the most refractory to traditional methods.     

Knowledge-directed vision: control, learning, and integration

The knowledge-directed approach to image interpretation popular in the 1980's, sought to identify objects in unconstrained two-dimensional (2-D) images and to determine the three-dimensional (3-D) relationships between these objects and the camera by applying large amounts of object- and domain-specific knowledge to the interpretation problem. Among the primary issues faced by these systems were variations among instances of an object class and differences in how object classes were defined in terms of shape, color, function, texture, size, and/or substructures. This paper argues that knowledge-directed vision systems typically failed for two reasons. The first is that the low- and mid-level vision procedures that were relied upon to perform the basic tasks a vision were too immature at the time to support the ambitious interpretation goals of these systems. This problem, we conjecture, has been largely solved by recent advances in the field of 3-D computer vision particularly in stereo and shape reconstruction from multiple views. The other impediment was that the control problem for vision procedures was never properly addressed as an independent problem. This paper reviews the issues confronted by knowledge-directed vision systems, and concludes that inadequate vision procedures and the lack of a control formalism blocked their further development. We then briefly introduce several new projects which, although still in the early stage of development, are addressing the complex control issues that continue to obstruct the development of robust knowledge-directed vision systems     

Anti-gliadin antibodies in patients with celiac disease cross-react with enterocytes and human calreticulin

The proper folding of aggregation-prone recombinant proteins in Escherichia coli can be facilitated by co-overexpressing specific molecular chaperones or by culturing the cells in the presence of ethanol or other agents that upregulate the synthesis of all heat-shock proteins (hsps). We have investigated the effect of combining direct chaperone overproduction with ethanol supplementation on the cytoplasmic folding of two aggregation-prone model proteins, preS2-S'-beta-galactosidase and human SPARC. In 25-ml shake flask cultures grown at 30 degrees C, addition of 3% (v/v) ethanol to the growth medium prior to inoculation improved the chaperone-mediated increase in the yields of active preS2-S'-beta-galactosidase 1.5- to 2-fold. When cultures overexpressing the dnaKJ operon were grown in the presence of ethanol, the levels of enzymatic activity were 5-fold higher relative to control cells and preS2-S'-beta-galactosidase aggregation was almost entirely abolished. Combining DnaK-DnaJ overexpression and growth of the cells at temperatures lower than 30 degrees C did not result in a comparable increase in activity. Although the individual effects of ethanol supplementation and dnaKJ overproduction were more limited when the culture volume was raised, a synergistic improvement in preS2-S'-beta-galactosidase activity was observed when the two approaches were used in concert. In contrast, ethanol supplementation promoted the aggregation of human SPARC, a protein exhibiting a chaperone dependency similar to that of preS2-S'-beta-galactosidase. Our results show that ethanol can exert complex and divergent effects on inclusion body formation and that the beneficial effect of the solvent on recombinant protein folding cannot simply be explained by an increase in the intracellular concentration of molecular chaperones.