Determination of trace levels of niguldipine in urine and blood by adsorptive stripping voltammetry at the hanging mercury drop electrode

Smyth line (SL) chickens spontaneously develop a posthatch autoimmune loss of pigment cells (vitiligo) in the feather. Concurrent with the development of Smyth line vitiligo (SLV), mononuclear cell infiltration and altered T cell profiles can be observed in the pulp of developing feathers. To determine whether the development of SLV is preceded by or associated with alterations in blood lymphocyte and leukocyte populations, blood leukocyte profiles were established at various times prior to and throughout the spontaneous development of SLV. The proportions among various blood leukocyte populations (percentage of lymphocytes, monocytes, heterophils, eosinophils, and basophils) were determined by immunofluorescence and flow cytometric analyses. Lymphocyte markers included fluorescence-conjugated monoclonal antibodies to identify T cells (CD3), T helper cells (CD4), cytotoxic T cells (CD8), and B cells (IgM). The proportions among blood lymphocyte populations examined did not differ between SL and MCH-matched parental Brown line (BL) control chickens prior to and throughout the development of SLV. Compared to BL controls, SL chickens had, however, increased proportions of inflammatory leukocytes in the blood, particularly at the time when most hatchmates developed SLV. Examination of leukocyte alterations with respect to first observation of SLV revealed that inflammatory leukocyte levels were elevated early in SLV. Although altered leukocyte profiles in the blood were observed during the development of SLV, blood from SL chickens did not reflect alterations in lymphocyte populations known to occur at the site of melanocyte destruction. The role of inflammatory blood leukocytes in the development of SLV needs to be further investigated.     

Is urine leukocyte esterase test a useful screening method to predict Chlamydia trachomatis infection in women?

We evaluated the use of the leukocyte esterase test (LET) on first-catch urine specimens from women as a screening test to predict infection with Chlamydia trachomatis. For diagnosis, we used Abbott's ligase chain reaction (LCR) on urine specimens and isolation by tissue culture (TC) on cervical brushes. Of 4,053 women attending sexually transmitted disease and family planning clinics, 4.3% (n = 174) were positive by TC and 5.9% (n = 239) were positive by LCR. When LET was compared to TC, the sensitivity, specificity, positive predictive value, and negative predictive value were 54.0, 67.0, 6.8, and 97.0%, respectively. The corresponding performance of LET versus LCR was 53.1, 67.3, 10.1, and 95.8%. Almost half of the laboratory-confirmed chlamydial infections were negative by LET. The low specificity probably reflects multiple causes of pyuria in women and results in a low positive predictive value. LET is neither sensitive nor specific as a predictor of chlamydial infection and cannot be recommended for use as a screening test for C. trachomatis with first-catch urine samples from females from low- or moderate-prevalence populations.     

Adult survivors of childhood sexual abuse. Do I have them in my practice?

The long term sequelae of childhood sexual abuse include many symptoms commonly encountered in general practice settings. Guidelines to empathic history taking, comprehensive assessment, and an overview of management are presented, together with a contextual background.     

Structure and properties of refractories based on zirconia stabilized by gadolinium oxide

The structure and properties of solid solutions and the chemical compound Gd₂Zr₂O₇ in the Gd₂O₃ - ZrO₂ system are investigated. Sintering of the initial mixture is studied and the optimum concentration of the stabilizing additive is determined for the production of heat-resistant articles from granular mixtures based on ZrO₂ stabilized by Gd₂O₃ and fired at 1750°C. Properties of specimens prepared by the technology developed are presented. Translated from Ogneupory, No. 3, pp. 12 – 16, March, 1996.     

Frequency transfer function of an opto-pneumatic detector

An example of an opto-pneumatic detector's (OPD) frequency transfer function is presented for the development of an opto-pneumatic interface. The theoretical model is tested through experiments in the laboratory on a real OPD prototype. In this way many of the model's parameters are studied and evaluated, such as the dimensions of the gas chamber, the thickness of the absorbent body, and the load of the OPD. The results obtained are good and show the utility of the studies described here.     

The water purification system for the low background counting test facility of the Borexino experiment at Gran Sasso

The Borexino experiment, for the study of solar neutrino physics, requires radiopurity at the level of 5 × 10⁻¹⁶ g/g ²³⁸U equivalent (or 6 × 10⁻⁹ Bq/kg) on a detector mass of many tons of scintillator. Feasibility studies are performed in a counting test facility now operating at LNGS, which consists of 4 t of liquid scintillator viewed by 100 photomultipliers and shielded by 100 t of water. The accomplishment of this goal requires the shielding liquid, water, to be at the 10⁻¹³ g/g contamination level (1.2 × 10⁻⁶ Bq/kg) or better. This paper describes the water purification system; it consists of a combination of several purification processes to remove particulate, radioactive ions, dissolved gases and other impurities. Residual contaminations are measured by analytical or direct-counting techniques. For radon measurement, particularly challenging at this low activity levels, a low background counting method has been developed.     

Low-voltage BiCMOS dynamic minimum circuit using a parallelcomparison algorithm for fuzzy controllers

The authors present a low-voltage BiCMOS dynamic minimum circuit using a parallel comparison algorithm for VLSI implementation of fuzzy controllers. Using low-voltage BiCMOS dynamic circuits and a parallel comparison algorithm, a four-4-bit-input minimum circuit designed, based on a 1μm BiCMOS technology, shows a 9.5ns comparison time, which is a ×2.5 improvement in speed as compared to that based on CMOS technology     

Crystal structures of Escherichia coli and Salmonella typhimurium 3-isopropylmalate dehydrogenase and comparison with their thermophilic counterpart from Thermus thermophilus

The basis of protein stability has been investigated by the structural comparison of themophilic enzymes with their mesophilic counterparts. A number of characteristics have been found that can contribute to the stabilization of thermophilic proteins, but no one is uniquely capable of imparting thermostability. The crystal structure of 3-isopropylmalate dehydrogenase (IPMDH) from the mesophiles Escherichia coli and Salmonella typhimurium have been determined by the method of molecular replacement using the known structure of the homologous Thermus thermophilus enzyme. The structure of the E. coli enzyme was refined at a resolution of 2.1 A to an R-factor of 17.3%, that of the S. typhimurium enzyme at 1.7 A resolution to an R-factor of 19.8%. The three structures were compared to elucidate the basis of the higher thermostability of the T. thermophilus enzyme. A mutant that created a cavity in the hydrophobic core of the thermophilic enzyme was designed to investigate the importance of packing density for thermostability. The structure of this mutant was analyzed. The main stabilizing features in the thermophilic enzyme are an increased number of salt bridges, additional hydrogen bonds, a proportionately larger and more hydrophobic subunit interface, shortened N and C termini and a larger number of proline residues. The mutation in the hydrophobic core of T. thermophilus IPMDH resulted in a cavity of 32 A3, but no significant effect on the activity and thermostability of the mutant was observed.     

An investigation of seated postural stability

Results of tests undertaken to identify which measures of seated posture control are most effective in two areas, distinguishing differences in the x and y direction control strategies for a given task and distinguishing differences in overall control strategies for pairs of different tasks, are presented. The test platform, calibration tests, test protocol, and data analysis method are described. The results of statistical analyses performed on the data are summarized