Etiopathogenesis of ankylosing spondylitis and reactive arthritis

In ankylosing spondylitis and reactive arthritis, an interplay of microbe and major histocompatibility complex initiates a sequence of events resulting in chronic inflammation. With the use of molecular probes as direct evidence and immune response patterns as indirect evidence, a strong case has been made for a central role of local microbial antigen in reactive arthritis. Cofactors such as gender, persistent gut inflammation, and antibiotic treatment may contribute to this process. Studies of transgenic rats and of familial spondylitis implicate B27 itself as the critical host variable. The results of recent studies point to intimate B27-bacteria interrelationships. HLA-B27 and proteins from enteric bacteria are structurally related, in a manner that may affect T cell response to enteric pathogens. B27 also may directly affect host-microbe interactions by modulating the invasive potential of these bacteria into target cells. Studies are in progress to apply the predictions of these in vitro systems to the in vivo situations of these diseases. The insights of research in the spondyloarthropathies may find broad applications in the rheumatic diseases.     

Computerized microassay of keratinocyte cell-plastic attachment and proliferation for assessing net stimulatory, inhibitory and toxic effects of compounds on nonimmortalized cell lines

Testing of pharmacological agents that affect growth of epidermal keratinocytes (EK) requires a standardized assay. We have developed an assay measuring net effects of stimulatory (e.g. growth factors), inhibitory (e.g. methotrexate) or toxic (e.g. Triton X-100) compounds. The amount of crystal violet staining viable EK attached to the wells of standard 96-well microplates is measured in situ using an ELISA plate reader. Optical density readings are directly converted into cell counts by computer software. Counts obtained by this method strongly correlate with the results obtained using the [3H]thymidine uptake assay and direct cell counts. The assay standardizes measurements of nonimmortalized EK lines with different innate proliferative properties and allows accurate quantitation of EK numbers in the range of 2,500-500,000 EK/well.     

Accurate determination of chemical composition of urinary calculi by spiral computerized tomography

PURPOSE: Choice of efficacious clinical management of symptomatic renal calculi can be facilitated by ascertaining the precise chemical composition of the calculus. Spiral computerized tomography (CT) is becoming a frequently used radiographic examination to establish the diagnosis and severity of calculus disease. Our objective for this study was to determine the precision of spiral CT in identifying the chemical composition of 6 different types of urinary calculi with region of interest measurements using spiral CT. MATERIALS AND METHODS: A total of 102 chemically pure stones were separated into 6 groups. The stones along with phantoms containing butter (fat) and jello (water) were mounted vertically in the scanner gantry. Then 1 mm. thickness scanning was performed with a high speed scanner at the 2 energy levels of 80 and 120 kV. The determination of the chemical composition was performed using the absolute CT value measured at 120 kV. and the dual kilovolt CT values measured at 80 and 120 kV. Hounsfield unit at 80 kV.-Hounsfield unit at 120 kV.). RESULTS: The absolute CT value measured at 120 kV. was able to identify precisely the chemical composition of uric acid, struvite and calcium oxalate stones. It was imprecise in differentiating calcium oxalate from brushite stone and struvite from cystine stone. However, dual kilovolt CT value was able to differentiate these latter stones with statistical significance (p < 0.03). Uric acid stones were easily differentiated from all other stones using the absolute CT value. CONCLUSIONS: This study demonstrates that the chemical composition of urinary calculi can be accurately determined by CT scanning in an in vitro setting.     

Transfer of human adenine deaminase gene into murine hematopoietic stem cells: sequential study of spleen colony-forming units from bone marrow of living mice and the requirement of the microenvironment

PURPOSE: To explore relationships between pregnant women's childhood experiences with discipline and 1) prenatal plans for disciplining own child and 2) later maternal-infant interactions DESIGN: Prospective correlation study. SETTING: Prenatal clinics and home visits PARTICIPANTS: Low-income pregnant women (N = 205) with a mean educational level of 12 years MAIN OUTCOME MEASURES: Adapted Ways of Handling Irritating Behaviors (Mother and You) Scales, NCAST Teaching Scale, Home Observation for Measurement of the Environment Scale RESULTS: Correlations between childhood experiences with discipline and 1) plans for later discipline strategies with own child and 2) infant components of maternal-infant interactions, including clarity of cues and responsiveness to the mother CONCLUSIONS: Prenatal assessment for childhood experiences with discipline may uncover factors associated with a break in the trajectory for optimal maternal-child interactions described by Barnard's theoretical framework.     

Clinical relevance of calreticulin in systemic lupus erythematosus

Calreticulin is an abundant intracellular protein which is proposed to have numerous biological functions. However, there is increasing evidence to suggest that calreticulin plays a multifunctional role as an autoantigen present in patients with systemic lupus erythematosus. In this review we detail some of the recent evidence which indicate that calreticulin may play a supportive role in the formation of the autoantigen complex-Ro/SS-A. In addition, several proposed mechanisms of release and surface expression of calreticulin are described in relation to SLE mediated responses to the autoantigen. In particular, the generation of autoantibodies to specific regions of the protein and the ability of calreticulin to interfere with complement mediated inflammatory processes.     

A high efficiency technique for the generation of transgenic sugar beets from stomatal guard cells

An optimized protocol has been developed for the efficient and rapid genetic modification of sugar beet (Beta vulgaris L.). A polyethylene glycol-mediated DNA transformation technique could be applied to protoplast populations enriched specifically for a single totipotent cell type derived from stomatal guard cells, to achieve high transformation frequencies. Bialaphos resistance, conferred by the pat gene, produced a highly efficient selection system. The majority of plants were obtained within 8 to 9 weeks and were appropriate for plant breeding purposes. All were resistant to glufosinate-ammonium-based herbicides. Detailed genomic characterization has verified transgene integration, and progeny analysis showed Mendelian inheritance.     

Silicon MOSFETs on insulator with lithography-independent 100 nm channel length

Future field-effect transistors should have control regions — also called channels or barriers — of a few tens of nanometers to achieve a transconductance of 1 S/mm and beyond, ƒ_T of 100 GHz and safe operating voltages beyond 1 V. This paper presents two approaches for the fabrication of such MOS transistors in silicon on insulator (SOI) on today's average technology lines without resorting to nanometer lithography, but rather using differential doping available in reduced-temperature epitaxy and implantation. With 6 nm oxynitride gate dielectrics, inner transconductances of 700 mS/mm at room temperature are reported.     

In Vivo Digestibility of Insoluble Collagen from Bovine Tendon as Influenced by the Inhibition of Gastric Acid Secretion

Insoluble collagen (bovine Achilles tendon), gelatin and meat were each mixed with whole egg protein (about 50% of the nitrogen) and fed to rats. True digestibility was evaluated after inhibiting gastric acid secretion with omeprazole. Insoluble collagen, supplemented with small amounts of essential amino acids, was also given but without inhibiting gastric acid secretion. Egg protein was fully digested and not affected by inhibition. The true digestibility of insoluble collagen/egg was 85%, corresponding to 71% true digestibility for insoluble collagen alone. This was significantly lower than the value of 95% obtained for insoluble collagen without inhibiting gastric acid secretion. True digestibilities for gelatin/egg were 99% and meat/egg 98%. Inhibition of gastric acid secretion thus did not affect digestion of gelatin and meat.