A comparative effect of the experimental diet on growth and development of rats

There are presented the results of a comparative assessment of the semi-synthetic casein diet, traditionally used by Institute of Nutrition RAMS, and the AIN-93 purified diet, offered by the American Institute of Nutrition, on growth and development of rats. A total of 60 male Wistar rats were used at 90-days experiment, rats were divided into two groups: first group received the semi-synthetic casein diet, the second group--AIN-93 diet. Analysis of integral, hematological and biochemical parameters revealed some differences between groups, but values of all studied parameters were within the physiological norm for Wistar rat. Based on the results of this experiment were suggested a new formulation of a diet for laboratory animals.     

B-lymphoproliferative disorders in patients with hepatitis C virus infection

Blastomycosis is an endemic systemic fungal infection that usually involves the lungs and superficial skin. Although head and neck involvement has been reported in the literature, no previous cases of neck mass resulting from direct extension of a pulmonary lesion have been published. We encountered an immunocompetent 31-year-old woman with a rapidly enlarging subcutaneous neck mass and a chronic upper lung infiltrate. Imaging studies showed contiguity between both lesions. Blastomyces dermatitidis was recovered from the sputum, and typical yeast was observed in fungal stains of needle aspirate from the neck mass. The patient responded favorably to a 6-month course of itraconazole. Blastomycosis should be considered in patients with subcutaneous neck masses in areas where this disease is endemic.     

Ifosfamide and vinorelbine: an active regimen for patients with relapsed or refractory Hodgkin's disease

Twenty-six patients with relapsed or refractory Hodgkin's disease (HD) were treated with an intensive salvage regimen combining ifosfamide (3000 mg/m2/d, days 1-4 through continuous intravenous infusion) and vinorelbine (25 mg/m2, i.v. days 1 and 5) with mesna uroprotection and G-CSF support. Courses were given at 3-week intervals. Ten patients achieved a complete and 10 patients a partial response, yielding an overall response rate of 77%. The main toxic effect was neutropenia and the combination was well tolerated.     

An updated review of environmental estrogen and androgen mimics and antagonists

For the last 40 y, substantial evidence has surfaced on the hormone-like effects of environmental chemicals such as pesticides and industrial chemicals in wildlife and humans. The endocrine and reproductive effects of these chemicals are believed to be due to their ability to: (1) mimic the effect of endogenous hormones, (2) antagonize the effect of endogenous hormones, (3) disrupt the synthesis and metabolism of endogenous hormones, and (4) disrupt the synthesis and metabolism of hormone receptors. The discovery of hormone-like activity of these chemicals occurred long after they were released into the environment. Aviation crop dusters handling DDT were found to have reduced sperm counts, and workers at a plant producing the insecticide kepone were reported to have lost their libido, became impotent and had low sperm counts. Subsequently, experiments conducted in lab animals demonstrated unambiguously the estrogenic activity of these pesticides. Man-made compounds used in the manufacture of plastics were accidentally found to be estrogenic because they fouled experiments conducted in laboratories studying natural estrogens. For example, polystyrene tubes released nonylphenol, and polycarbonate flasks released bisphenol-A. Alkylphenols are used in the synthesis of detergents (alkylphenol polyethoxylates) and as antioxidants. These detergents are not estrogenic; however, upon degradation during sewage treatment they may release estrogenic alkylphenols. The surfactant nonoxynol is used as intravaginal spermicide and condom lubricant. When administered to lab animals it is metabolized to free nonylphenol. Bisphenol-A was found to contaminate the contents of canned foods; these tin cans are lined with lacquers such as polycarbonate. Bisphenol-A is also used in dental sealants and composites. We found that this estrogen leaches from the treated teeth into saliva; up to 950 microg of bisphenol-A were retrieved from saliva collected during the first hour after polymerization. Other xenoestrogens recently identified among chemicals used in large volumes are the plastizicers benzylbutylphthalate, dibutylphthalate, the antioxidant butylhydroxyanisole, the rubber additive p-phenylphenol and the disinfectant o-phenylphenol. These compounds act cumulatively. In fact, feminized male fish were found near sewage outlets in several rivers in the U.K.; a mixture of chemicals including alkyl phenols resulting from degradation of detergents during sewage treatment seemed to be the causal agent. Estrogen mimics are just a class of endocrine disruptors. Recent studies identified antiandrogenic activity in environmental chemicals such as vinclozolin, a fungicide, and DDE, and insecticide. Moreover, a single chemical may produce neurotoxic, estrogenic and antiandrogenic effects. It has been hypothesized that endocrine disruptors may play a role in the decrease in the quantity and quality of human semen during the last 50 y, as well as in the increased incidence of testicular cancer and cryptorchidism in males and breast cancer incidence in both females and males in the industrialized word. To explore this hypothesis it is necessary to identify putative causal agents by the systematic screening of environmental chemicals and chemicals present in human foods to assess their ability to disrupt the endocrine system. In addition, it will be necessary to develop methods to measure cumulative exposure to (a) estrogen mimics, (b) antiandrogens, and (c) other disruptors.     

Estimation of Ethanol Yield in Corn Mash Fermentations Using Mass of Ash as a Marker

An equation to estimate the ethanol yield by mass of ash in fermentation was generated. The equation was based on the assumption that mass of ash does not change during the course of fermentation. Ethanol yield estimated by the mass of ash equation was validated by contrasting it to ethanol yield obtained by the distillation method. Results showed no difference (P = 0.925) in yields estimated by the aforementioned methods. Furthermore, this innovative method was tested in three fuel ethanol plants located in the American Midwest. The results from each of these plants showed that the ethanol yield estimated by mass of ash is valid, consistent and can be used to compare individual fermentations and/or treatments.     

Radiosensitization and apoptosis

The toxicity of radiation to living tissues was discovered soon after the discovery of radioactivity itself and this toxicity is the basis for cancer therapy with radiation. Although this mode of therapy is often effective, its success is far from assured. One major difficulty in the implementation of radiotherapy is that normal tissues are also sensitive to killing by radiation so that treatment is often limited by the tolerance of normal tissues for radiation. Thus methods that sensitize tumor cells while sparing normal tissues could potentially lead to greater success with radiation as a therapy. Oncogenes are frequently altered in tumors, but are not in normal tissue making them potential targets for altering radiosensitivity and apoptosis in tumors.     

High deposition rate of amorphous silicon thick layers using a gas mixture of 10% silane in hydrogen

The deposition rate of amorphous silicon of the order of 0.9 μm/h, has been obtained using a gas mixture of 10% silane (SiH₄) in hydrogen (H₂), with a RF source of 13.56 MHz. Best films were deposited at a total flow rate of 100–200 sccm, 300°C substrate temperature, 66.7 Pa, and RF power density of 150 mW/cm². The geometrical configuration of the reaction chamber included a gas injector that was specially designed for this purpose. Films were characterized by Fourier transform infrared (FTIR), secondary ion mass spectrometry (SIMS), and profilometer. In addition, thick p-i-n diodes were prepared and characterized, obtaining reverse current densities lower than 5×10⁻⁶ A/cm² at full depletion.     

Hyperelliptic curves encryption combined with block codes for Gaussian channel

In this paper, a new cryptographic system is constructed using a combination of a hyperelliptic curve of genus g = 2 over the Galois field GF(2ⁿ) and a Reed–Solomon code (N, K) over the Galois field GF(2^m) and this system uses a smaller key than the elliptic curves cryptosystem and the Rivest, Shamir, and Adleman cryptosystem. The design criterion for the combination can be expressed as the data compression condition and addressing capability of the code. In addition, the system performance is compared with other systems; extraordinary improvements of 8 and 16.5 dB can be obtained for a BER = 10^?5, when compared with binary phase shift keying and differential chaos shift keying, respectively. This system has a polynomial complexity, which depends on data length and the number of operations in GF(2ⁿ). Copyright © 2005 John Wiley & Sons, Ltd.     

BSD extent, an index for metal pollution screening based on the metal content within digestive cell lysosomes of mussels as determined by autometallography

The extent of autometallographical black silver deposits (BSD) has been semiquantified at the light microscope in the gills and digestive gland of either control mussels or Zn-polluted mussels after depuration and on exposure to sublethal concentrations of Cu, Zn, and Cd. The BSD extent in the gills and digestive gland of control mussels was much reduced compared to that in other experimental mussels. The extent of BSD in the gills of depurating mussels was reduced at short depuration times due to decreased levels in the abfrontal cells while in the digestive gland it did not change with the depuration period. The extent of BSD in digestive lysosomes of Cu- and Zn-exposed mussels followed a logarithmic pattern in relation to metal concentration increasing with metal concentrations in the digestive gland. However, a reduced extent of BSD was related to the presence of high metal concentrations under Cd-exposure conditions. This is because the great extent of BSD present in the lumen of the digestive tubules was not taken into account to carry out semiquantification, but, however, the chemical analysis measured the Cd content of these BSD. As such, the extent of BSD in digestive lysosomes followed a logarithmic pattern with total metal concentrations in the digestive gland of Cd-exposed mussels. Therefore, the semiquantitative estimation of BSD in the digestive lysosomes could be considered a reliable index to reflect changes in metal bioavailability in sea water.     

A review of methodologies for assessing drug effectiveness and a new proposal: randomized database studies

The need to evaluate the effects of health technologies in clinical practice is increasingly important. In this article, we review the advantages and limitations of naturalistic randomized clinical trials (RCTs) and database analyses, the two primary methods for evaluating treatment effectiveness. Also, we comment on a newer research strategy, cross-design synthesis, which proposes the complementary use of both experimental RCTs and observational database methodologies to avoid the main weaknesses of each: respectively, the lack of external and internal validity. Finally, we propose a new strategy--randomized database studies--capable of generating results with an acceptable balance between internal and external validity. This strategy consists of the simultaneous use of both experimental and observational tools in the assessment of drugs' effectiveness. Randomization is essential to minimize comparison bias, and one possibility for such studies is that randomization modules could be included in computer-based patient records. Although we identify some of the difficulties in implementing the process, the progressive standardization of clinical practice and the development and widespread adoption of improved computer-based patient records could facilitate the use of randomized database studies as a new method of research.