Tuberculosis and HIV infection. Clinical characteristics and diagnosis

The in vitro radiosensitivity of dermal fibroblasts has been found to vary between individuals, and a number of studies have also shown that this parameter correlates with radiation-induced late injuries in clinical radiotherapy. In addition, certain genetic disorders are known to effect radiosensitivity, e.g. normal tissues of patients homozygous or heterozygous for the ataxia teleangiectasia gene show unusual sensitivity to radiation both in vivo and in vitro. Thus, it has been assumed that there is a genetically determined component resulting in a certain intrinsic cellular radiation response in an individual. To study this possible relationship between different cells of a specific patient, we established eight pairs of dermal and tumor fibroblast cultures. The donor patients had either adenocarcinoma of the uterus or squamous cell carcinoma (SCC) of the head and neck. The radiosensitivity of these strains was determined by a 96-well plate clonogenic assay, previously used by us for radiosensitivity testing of cancer cells. From a paired comparison, the values for the cell fraction surviving 2.0 Gy (SF2), of both fibroblast strains, were found to be on the same level in five out of eight cases. In patient 6, the SF2 of tumor fibroblasts was significantly higher than that of dermal fibroblasts (P=0.0014). In two additional cases the tendency was the same, but not statistically significant. As groups, the two types of fibroblasts did not differ from each other, mean SF2 values of 0.24+/-0.07 and 0.21+/-0.05, respectively. The SF2 of tumor fibroblasts from SCC patients proved to be significantly higher than that of the adenocarcinoma patients (P=0.030). These preliminary results indicate that the in vitro radiosensitivity of tumor fibroblasts correlates with normal cell sensitivity in many cases, but not in all. The radiosensitivity of tumor fibroblasts also seems to follow the level of in vitro radiosensitivity determined for the corresponding histological type of tumor cells. Further studies are needed to determine more closely the relationship between the radiosensitivities of tumor cells and tumor fibroblasts, thus evaluating the possibility of testing radiosensitivity from tumor fibroblasts in order to estimate tumor response.     

Active site-directed photoinactivation of delta 5-3-ketosteroid isomerase from Pseudomonas putida dependent on 1,4,6-androstatrien-3-one-17 beta-ol

delta 5-3-Ketosteroid isomerase from Pseudomonas putida is subject to photoinactivation by light of wavelengths greater than 300 nm, specifically in the presence of the competitive inhibitor, 1,4,6-androstatrien-3-one-17 beta-ol (TEO). In the absence of this steroid or in the presence of the nonchromophoric steroidal competitive inhibitor, deoxycholate, the enzyme activity is essentially unaffected by irradiation. Deoxycholate protects the enzyme from the TEO-dependent reaction to a degree which is predictable from the concentrations of deoxycholate and TEO and their respective competitive inhibition constants, thus demonstrating that the inititial velocity of the photoinactivation is dependent upon the fraction of enzyme active sites occupied by TEO. Cholate, which is not a competitive inhibitor, does not protect enzyme activity. Amino acid analyses of hydrochloric acid hydrolysates of the photoinactivated enzyme show no significant differences from that of the native enzyme. However, the fraction of initial enzyme activity remaining correlates quantitatively with the disappearance of one of the four thiol groups in each polypeptide chain of the enzyme. Enzyme irradiated under the same conditions in the absence of TEO does not lose thiol groups.     

27—SOLVENT-APPLIED FLAME-RESIST TREATMENTS FOR WOOL,COTTON, AND WOOL–COTTON BLENDS

Fluoro-complexes of titanium, zirconium, tin, and antimony improve the natural flame-resistance of wool when applied by a water-in-oil emulsion exhaustion technique in which common dry-cleaning solvents are used. Evaluations of limiting-oxygen and limiting-nitrous-oxide indices indicate that these complexes act predominantly in the solid phase, The treatments are fast to dry-cleaning but only the fluorotitanate and fluorozirconate treatments are fast to washing. Zinc fluoroborate is an effective flame-retardant for wool, cotton, and their blends, and it can be applied by exhaustion or spraying from solvent emulsions. This treatment is fast to dry-cleaning but is affected by washing.     

Issues in Foreign Outsourcing

The decision to outsource applications development and support to a foreign vendor involves not only the myriad issues pertinent to outsourcing in general, but a host of additional risks and challenges unique to firms operating in different legal and cultural environments. Careful assessment of these issues helps determine whether offshore outsourcing will realize its potential to reduce costs, improve software quality, and achieve economies of scale in skills acquisition.     

Stability and calorimetric studies of silico‐ferrites of calcium aluminum and magnesium

In a systematic study on silico‐ferrites of calcium aluminum and magnesium (SFCA phases) this investigation focuses on synthesis of silicon‐free SFCA‐type compounds with low‐MgO contents (~1.00 apfu—atoms per formula unit). Previous studies revealed the existence of iron‐rich SFCA phases similar to the SFCA‐I structure with the chemical composition Ca₃MgAl₆Fe₁₀O₂₈ (Metall Mater Trans B. 2017;48:2207). The experimental results in the quaternary Fe₂O₃‐CaO‐Al₂O₃‐MgO system confirm large stability fields of 2 silicon‐free ferrites FCAM‐I and FCAM‐III, which are members of the homologous series M_14+6nO_20+8n (n = 1, 2). Starting with compositions corresponding to Ca₃MgAl_xFe_16‐xO₂₈ (with increasing aluminum content from x = 0‐12 apfu), it was possible to synthesize these phases with an x‐value ≥2 apfu, which corresponds to Al₂O₃ contents ≥7.14 wt%. Synthesis of pure silicon‐free ferrites with n = 1 (FCAM‐I) and 2 (FCAM‐III) and silicon‐bearing ferrites with n = 0 (SFCA) was possible. Samples were characterized by electron probe microanalysis, powder diffraction, and subsequently studied using relaxation calorimetry measurements in combination with differential scanning calorimetry for determination of the heat capacities and standard entropies S°(298). The corresponding values are S°(298) = 650.3 ± 4.6 J/mol·K for SFCA, S°(298) = 864.5 ± 6.1 J/mol·K for FCAM‐I, and S°(298) = 1206.2 ± 8.4 J/mol·K for FCAM‐III. These thermodynamic data are a step toward a rigorous quantitative thermodynamic modeling of the iron ore sintering process.     

The uncertainty in determining the third law entropy by the heat-pulse calorimetric technique

Low-temperature heat capacities were measured on milligram-sized samples of various mineralogical materials with a heat-pulse calorimeter. The third law entropy was then calculated by fitting and integrating the c_p data. In order to determine the uncertainty of the third law entropy, a Monte Carlo technique was adopted to propagate errors through the integration process.Using single crystals, the relative uncertainty of the third law entropy is smallest and only little mass-dependent and amounts to ～0.2% of the total. Sample powders have a larger uncertainty that increases exponentially with decreasing sample mass. For heat-pulse calorimetric measurements on powders weighing 20 mg, derived standard entropies have a relative uncertainty of 0.9% increasing to 4%, if only 6 mg powder were used.     

Chrome Dyeing of Wool: Reducing the Amount of Chromium in the Residual Bath

The concentration of the residual Cr^VI and Or¹¹¹ in the dye-bath can be decreased to acceptable levels by incorporating a-hydroxymonocarboxylic acids in afterchrome dyeing using the normal dye to dichromate ratios, the most suitable being lactic acid. The mechanism is based on the reduction ofCr^VI to Cr¹¹¹ which appears to take place predominantly on the wool fibre. The optimum pH range for the treatment is 3.4 to 3.6. Compounds which are substantive to the wool fibre, such as sulphates, or form stable complexes with Cr^III such as ethylenediaminetetracetic acid, may increase the amount of the residual chromium in the bath. Other dicarboxylic and hydroxycarboxylic acids, which are also effective in reducing the concentration of the Cr^VI in the bath, form stable complexes with Cr¹¹¹, adversely affecting the concentration of the residual Cr¹¹¹ in the bath.