Minocycline-induced discolouration of the sclerae

Metal cations such as aluminum, magnesium, ferrous sulfate, and zinc are thought to form chelation complexes with fluoroquinolone antibiotics and prevent the drugs from being absorbed. Sucralfate, which has a high aluminum content, reduces the bioavailability of ciprofloxacin to approximately 4%. The concomitant administration of ciprofloxacin and sucralfate resulted in treatment failure for a patient with prostatitis and a subsequent 5-day hospitalization. Fluoroquinolone antibiotics should be administered at least 2 hours before agents containing metal cations to allow for their absorption. In addition, sucralfate should not be administered less than 6 hours before fluoroquinolone antibiotic administration.     

Calcium and phosphorus derangements

Derangements in plasma calcium and phosphorus concentrations can precipitate serious and life-threatening complications in critically ill patients. An understanding of the function and homeostasis of these ions is essential to fully comprehend the causes, clinical manifestations, and treatment of calcium and phosphorus imbalances. This article will help the critical care nurse to identify patients at risk, to recognize derangements early (while they are still mild), and to seek and monitor appropriate treatment.     

A diagnostic comparison of panoramic and intraoral radiographs

Elevated cellular immune responses against the cows' milk protein beta casein have been reported in individuals with Type I diabetes mellitus, a finding supportive of the concept that cows' milk consumption may be causative for the disease. We analysed cellular immune reactivities against beta casein in newly-diagnosed Type I diabetic patients, their immediate autoantibody negative relatives, and unrelated healthy individuals in order to further elucidate the role of anti-beta casein immunity in the pathogenesis of Type I diabetes mellitus. Peripheral blood mononuclear cells were stimulated in vitro with various concentrations of three different beta casein preparations, control antigens (tetanus toxoid, mumps extract) and a mitogen (phytohemagglutinin). The frequency and/or mean simulation index of cellular proliferation against two of the beta casein preparations at high antigen concentrations (i.e. 10 or 50 microg/ml) were significantly higher in newly-diagnosed Type I diabetic subjects compared with autoantibody negative healthy control subjects. However, reactivities against beta casein in the Type I diabetic probands and their autoantibody negative relatives, individuals with a very low-rate of disease development, were almost identical. Cellular immune reactivities to other antigens were similar between the subject groups. In addition to indicating the need for appropriately matched subject populations (e.g. human leukocyte antigen (HLA) matched relatives) when analysing cellular immune responses, these findings support our previous contention that individuals genetically prone to autoimmunity may be deficient in forming tolerance to dietary antigens. However, the significance of anti-beta casein immunity as a specific causative factor in the pathogenesis of Type I diabetes mellitus remains unclear.     

Biosensors: Control of Nanoscale Environment to Improve Stability of Immobilized Proteins on Diamond Surfaces (Adv. Funct. Mater. 6/2011)

Immunoassays for detection of bacterial pathogens rely on the selectivity and stability of bio‐recognition elements such as antibodies tethered to sensor surfaces. The search for novel surfaces that improve the stability of biomolecules and assay performance has been pursued for a long time. However, the anticipated improvements in stability have not been realized in practice under physiological conditions because the surface functionalization layers on commonly used substrates, silica and gold, are themselves unstable on time scales of days. In this paper, we show that covalent linking of antibodies to diamond surfaces leads to substantial improvements in biological activity of proteins as measured by the ability to selectively capture cells of the pathogenic bacterium Escherichia coli O157:H7 even after exposure to buffer solutions at 37 ºC for extended periods of time, approaching 2 weeks. Our results from ELISA, XPS, fluorescence microscopy, and MD simulations suggest that by using highly stable surface chemistry and controlling the nanoscale organization of the antibodies on the surface, it is possible to achieve significant improvements in biological activity and stability. Our findings can be easily extended to functionalization of micro and nanodimensional sensors and structures of biomedical diagnostic and therapeutic interest.     

Software Caching and Computation Migration in Olden

Software caching and computation migration are mechanisms that satisfy remote references by either bringing a copy of the data to the computation or moving the computation to the data. We evaluate these mechanisms usingOlden, a system that, with minimal programmer annotations, provides parallelism for C programs that use recursively defined structures, such as trees, lists, and DAGs. We demonstrate that providing both software caching and computation migration can improve the performance of these programs, and provide a compile-time heuristic that selects between them for each pointer dereference. We have implemented the heuristic in Olden on the Thinking Machines CM-5. We describe our implementation and report on experiments with eleven benchmarks.     

驱动感性负载的电路

在图1所示的驱动电路中,系统的控制电路可提供Vcommand信号,而Vcommand则等于所需负载电流乘以R_8°当控制电路把这个电压加在R_1上时,IC的输出电压增高,从而给Q_1和Q_2的栅极加上电压。这两个晶体管导通,从而负载电流经过Q_1和R_8流到地端。负载上的电流呈斜坡增加,而且由R_8感测的与负载电流成正比的一个电压将反馈给比较电路IC_1的反相     

A risk characterization for atrazine: oncogenicity profile

An extensive safety database has been developed for the chlorotriazine herbicide, atrazine. The results from five oncogenicity studies conducted in the Sprague-Dawley rat, two studies in the Fischer 344 rat, and two studies in the CD-1 mouse were reviewed. No increase in the incidence of tumors of any type was observed in male or female Fischer 344 rats, male or female CD-1 mice, or male Sprague-Dawley rats fed atrazine at a maximum tolerated level in their diet for 24 mo. Female Sprague-Dawley rats fed atrazine at levels of 400, 500, and 1000 ppm developed mammary tumors earlier than did the control group. The incidence of female Sprague-Dawley rats with mammary tumors after 24 mo of treatment was statistically increased at feeding levels of > or = 70 ppm in 1 study and at 400 ppm in a second study, whereas there were no significant differences between the treated and the control group in 3 other studies. No increase in tumors of any type was observed in ovariectomized female Sprague-Dawley rats after 24 mo of atrazine treatment at the highest level tested, 400 ppm. Therefore, the mammary tumor response in female Sprague-Dawley rats following the administration of high levels of atrazine appears to be due to an acceleration of the normal reproductive aging process resulting in increased exposure to endogenous estrogen and prolactin. The Sprague-Dawley rat differs from the Fischer 344 rat, the CD-1 mouse, and humans in the endocrine control mechanisms affecting reproductive senescence and the development of the mammary tumors during aging. These data indicate that the carcinogenic effect of high doses of atrazine observed in the female Sprague-Dawley is a strain-, sex-, and tissue-specific response that does not have biological relevance to humans.     

Increased vulnerability of hippocampal neurons to excitotoxic necrosis in presenilin-1 mutant knock-in mice

Before vaccination, Alaska Natives experienced very high rates of invasive Haemophilus influenzae type b (Hib) disease and carriage. Vaccination with Hib conjugate vaccine PRP-OMP (polyribosylribitol phosphate Neisseria meningitidis outer membrane protein) began in 1991 and resulted in a sharp decline in cases. In 1996, after switching to a different Hib conjugate vaccine, DTP-HbOC (which combines diphtheria-tetanus-whole cell pertussis vaccines with HbOC [Hib oligosaccharide CRM197]), cases of invasive Hib disease increased, suggesting ongoing Hib transmission despite widespread vaccination. To determine the prevalence of and risk factors for carriage, a cross-sectional study of oropharyngeal Hib carriage was conducted among Alaska Native children aged 1-5 years in remote southwestern Alaska. Of 496 children with swabs taken, 46 (9.3%) were colonized with Hib. Carriage rates varied by village from 2.2% to 13.2% and by age from 6.1% in 1-year-olds to 14.7% in 5-year-olds. Crowding was associated with Hib carriage. Widespread vaccination with PRP-OMP Hib conjugate vaccine did not eliminate carriage in this population of Alaska Natives, and ongoing carriage contributed to disease resurgence.