Development and certification of a standard reference material for vitamin D metabolites in human serum

The National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Health's Office of Dietary Supplements (NIH-ODS), has developed a Standard Reference Material (SRM) for the determination of 25-hydroxyvitamin D [25(OH)D] in serum. SRM 972 Vitamin D in Human Serum consists of four serum pools with different levels of vitamin D metabolites and has certified and reference values for 25(OH)D(2), 25(OH)D(3), and 3-epi-25(OH)D(3). Value assignment of this SRM was accomplished using a combination of three isotope-dilution mass spectrometry approaches, with measurements performed at NIST and at the Centers for Disease Control and Prevention (CDC). Chromatographic resolution of the 3-epimer of 25(OH)D(3) proved to be essential for accurate determination of the metabolites.     

Compact and flexible optical sensor designed for on-line monitoring

A new on line optical sensor based on light scattering dedicated to real-time monitoring during processing of polymers blends and polymers nanocomposites has been developed. The sensor is designed to monitor the quality of a polymer melt or of a dispersion of nanofillers in a polymeric matrix during the process of extrusion. This sensor presents three openings: two for light sensor setups (one for transmission measurements and the other for 90°-scattered light measurements) and one for the incident laser beam. The experimental validation of this optical sensor has been realized on two materials: poly(methyl methacrylate) (PMMA) and on the nanocomposites obtained by the melt mixing of this polymer matrix with modified montmorillonite (MMT) clays. Experimental results proved the good results in terms of signal repeatability and sensitivity to organoclay particle concentration and structures of nanocomposites respectively.     

Origin of hepatocellular carcinoma recurring after allotransplantation revealed by microsatellite analysis

A hepatocellular carcinoma was resected from a liver allotransplant after the patient's original organ had been removed because of a liver carcinoma. DNA analysis was performed to explore the origin of the carcinoma cells. DNA extracted from the carcinoma tissue, from the carcinoma free liver tissue, and from other cells of the recipient underwent polymerase chain reaction amplification for seven microsatellite systems and the X-Y amelogenin system. The allelic pattern from the carcinoma tissue was identical with that from the patient and differed from the DNA profile of the liver tissue. The result confirmed the assumption that the carcinoma tissue had originated from the patient and not from the donor.     

Failure of colostral immunoglobulin transfer in calves dying from infectious disease

Serum IgG1 concentrations of calves less than 3 weeks old and dying from infectious disease were significantly lower (P less than 0.01) than those of clinically normal calves. Fifty percent of the dead calves had serum IgG1 concentrations that were more than 2 standard deviations below the normal mean, and an additional 35% had IgG1 concentrations that were more than 1 standard deviation below the normal mean. Low IgG1 concentrations were attributed to failures in passive transfer of colostral immunoglobulin. The few calves dying of noninfectious causes generally had normal serum immunoglobulin concentrations. The results of this study emphasize the importance of adequate colostral intake and absorption to the neonatal calf. In view of the large numbers of calves that die from neonatal infection each year, it may be assumed that failure in passive transfer, as reflected by low serum immunoglobulin concentrations, is one of the most important factors influencing neonatal calf mortality.     

Frequency Upconversion of 800 nm Ultrashort Pulses by Two‐Photon Absorption in a Stilbenoid Compound‐Doped Polymer Optical Fiber

We present the results of a study of frequency upconversion of femtosecond optical pulses in a step‐index polymer optical fiber that uses a stilbenoid compound as an active dopant. Intense blue emission is observed in the doped poly(methyl methacrylate) (PMMA) fiber when it is longitudinally pumped at 800 nm by 175 fs optical pulses. By means of the intensity‐dependent transmission method, the two‐photon absorption cross‐section is deduced. Our study illustrates that the combination of a well‐designed organic chromophore incorporated into a fiber geometry is appealing for the development of an upconversion blue polymer laser.     

Prophylactic Nd:YAG-laser iridotomy versus surgical iridectomy: a randomized, prospective study

Both surgical iridectomy and YAG-laser iridotomy have been shown to prevent angle-closure glaucoma. However, it remains unknown as to which procedure is superior. We therefore conducted a prospective randomized study, which compared the effect of the two methods on visual acuity, intraocular pressure, endothelial cell density, depth of the anterior chamber, and iris configuration as well as acceptance by the patients. A total of 30 patients, who were treated for acute angle-closure glaucoma in one eye, were subjected to either surgical iridectomy or Nd:YAG-laser iridotomy in the other eye according to a randomized protocol. All patients were followed for 12 months by examination at the 1st, 6th, and 12th month post treatment. No significant difference between the two treatments was found regarding visual acuity or intraocular pressure. The peripheral anterior chamber increased in depth following both methods, whereas the central depth of the anterior chamber was unaffected. A better gonioscopic visibility of the trabecular meshwork resulted from the increased width of the chamber angle. Whereas the number of endothelial cells remained constant in the patients treated with laser iridotomy, a small decrease was observed in the group of patients who underwent iridectomy (-7.2% after 12 months; difference not significant). The subjective acceptance by the patients was better in the group treated with laser iridotomy. We conclude that the two methods are equivalent with regard to intraocular pressure and visual acuity. The constant number of endothelial cells and the better acceptance by the patients suggest Nd:YAG-laser iridotomy to be the preferable method for prophylaxis of acute angle-closure glaucoma.     

Appraisals of control and predictability in adapting to a chronic disease.

In a sample of 92 patients with rheumatoid arthritis, we examined interrelations among various control appraisals, illness predictability, psychosocial adjustment, mood, and illness status. Perceiving greater personal control over the disease and symptoms and perceiving greater health-care-provider control over symptoms were associated with greater illness predictability. Patients reported more personal control over their symptoms than over the course of the disease and thought that their health care providers had more control over disease course than they did themselves. Multiple regression analyses showed that perceiving greater personal control over one's medical care and treatment was associated with positive mood and psychosocial adjustment. Negative mood was also associated with the belief that providers have greater control over the patient's daily symptoms. Patients who had a more severe disease and expressed greater personal control over its course reported greater mood disturbance and were rated as exhibiting less positive adjustment, but those who had more severe daily symptoms and expressed greater personal control over their symptoms reported less mood disturbance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)