Characterization of peptide and amino acid profile in casein hydrolysates

The nutritional quality of protein hydrolysates has been related in several reports to their di- and tripeptide contents. In the present work different hydrolytic conditions were tested using papain in order to prepare casein hydrolysates with a suitable peptide profile for being used in special diets. The hydrolysates were fractionated by size-exclusion HPLC and the rapid Correct Fraction Area method was used for quantifying the peptides. Among the five hydrolytic conditions studied, three of them gave rise to preparations having nutritionally similar peptide profiles. However, the use of the temperature of 37 degrees C and enzyme:substrate ratio (E:S) of 2% may probably be the most economical condition for industrial production.     

Urea biosensors based on immobilization of urease into two oppositely charged clays (laponite and Zn-Al layered double hydroxides)

Enzyme-based field effect transistors (ENFETs) for urea determination were developed based on the immobilization of urease within two different clay matrixes, one cationic (Laponite) and the other anionic (layered double hydroxide (LDH)), cross-linked with glutaraldehyde. The biosensor based on the enzyme immobilized in Laponite shows a greater sensitivity and smaller dynamic linear range, because the enzymatic reaction is protected from the effect of the buffer capacity of the outer medium. The apparent Michaelis-Menten constant, Km(app), is quite similar for both biosensors. Inhibition of the enzyme by sodium tetraborate was investigated. Tetraborate acts as a competitive inhibitor for urease in the two different types of clay, the inhibitor effect being stronger for the LDH/urease biosensor. In particular, the maximum limit of the dynamic linear range extends from 1.4 mM in the absence of the inhibitor to 12 mM in the presence of 0.5 mM tetraborate. The Km(app) values in the presence of 0.5 mM tetraborate for Laponite and LDH biomembranes were 10 and 62 mM, respectively. Comparison of the inhibition constant values, Ki 0.16 and 0.05 mM for Laponite and LDH biosensors, respectively, clearly indicates a stronger enzyme-inhibitor interaction in the LDH/urease biomembrane.     

Chemical and microbiological quality of grass carp (Ctenopharyngodon idella) slaughtered by different methods

The effect of two slaughter methods (immersion in ice-water slurry and electrical stunning followed by ice slurry asphyxiation) on chemical and microbiological parameters of grass carp (Ctenopharyngodon idella) stored in ice for 20 days was evaluated. No differences in total volatile basic nitrogen (TVB-N), pH, carbohydrate or protein content of mucus were observed between the slaughter methods. Ice-slaughtered fish had lower bacteria counts at the beginning of storage, but higher counts than fish slaughtered by electricity at the end of storage (p < 0.05). However, no significant differences in the shelf life were observed between the slaughter methods evaluated (limit of acceptability – counts > 3 × 10⁶ CFU g⁻¹ – attained after 13–16 days). Results indicated that the chemical parameters evaluated have a limited applicability to assess the shelf life of grass carp stored in ice, since pH limit (6.8) was exceeded after 4 days, while TVB-N limit (30 mg%) was not attained after 20 days of storage.     

Molecular analysis of the retinoblastoma (RB1) gene in acute myeloid leukemia patients

Patient 1: A 48-year-old man was admitted to Osaka Red Cross Hospital because of fever and dyspnea. Laboratory examination revealed pancytopenia, liver dysfunction and hematostatic abnormality. Chest radiographs obtained on admission revealed ground-glass opacity in both lung fields, and an analysis of arterial blood showed severe hypoxemia (PaO2:46.8 Torr). Pulse therapy with methylprednisolone was started. Although the hypoxemia subsided and radiographic findings rapidly improved, pancytopenia persisted. Examination of bone marrow aspirate revealed mature histiocytes with marked hemophagocytosis. Amplified Mycobacterium tuberculosis direct tests of bronchoalveolar lavage fluid, sputum, urine, and bone marrow were all positive, and Mycobacterium tuberculosis was cultured from sputum and urine. Although the patient was taking antituberculous agents, his pancytopenia persosted. Treatment with etoposide induced remssion. Patient 2: A 19-year-old woman was admitted to Osaka Red Cross Hospital because of prolonged cough and fever. Laboratory examination revealed leukocytosis, liver dysfunction, and hematostatic abnormality. Serologic tests provided conclusive evidence of Mycoplasma infection and a CRP test was strongly positive. Chest radiographs obtained on admission revealed infiltration shadows in the middle and lower lung fields on both sides, with left pleural effusion. An analysis of arterial blood showed hypoxemia (PaO2: 54.2 Torr). Examination of bone marrow and pleural effusion samples revealed mature histiocytes with marked hemophagocytosis. Although treatment with antibiotics and pulse therapy with methylprednisolone was started, the patients respiratory functions deteriorated. Endotracheal intubation was performed. Therapy with etoposide induced remission. Hemophagocytic syndrome associated with Mycoplasma infection and tuberculosis appears to be exceedingly rare. In these 2 cases, it was difficult to achieve remission with therapy for the underlying infections, but etoposide treatment was effective.     

Leadership and communication in nursing management

Considering communication and leadership, authors examine the role of the leader as a focus of reception and transmission of information, based on the classification of Mintzberg related to their informative roles, such as the leader acting as monitor, disseminator and spokesman. Contextualizing this approach in the scenery of nursing management, authors study the dimension of nurses-leaders role as an essential element of communication in the systems of organization of nursing care.     

A validation of object-oriented design metrics as qualityindicators

This paper presents the results of a study in which we empirically investigated the suite of object-oriented (OO) design metrics introduced in (Chidamber and Kemerer, 1994). More specifically, our goal is to assess these metrics as predictors of fault-prone classes and, therefore, determine whether they can be used as early quality indicators. This study is complementary to the work described in (Li and Henry, 1993) where the same suite of metrics had been used to assess frequencies of maintenance changes to classes. To perform our validation accurately, we collected data on the development of eight medium-sized information management systems based on identical requirements. All eight projects were developed using a sequential life cycle model, a well-known OO analysis/design method and the C++ programming language. Based on empirical and quantitative analysis, the advantages and drawbacks of these OO metrics are discussed. Several of Chidamber and Kemerer's OO metrics appear to be useful to predict class fault-proneness during the early phases of the life-cycle. Also, on our data set, they are better predictors than “traditional” code metrics, which can only be collected at a later phase of the software development processes     

Structure and rheology of semisolid o/w creams containing cetyl alcohol/non-ionic surfactant mixed emulsifier and different polymers

Oil-in-water (o/w) emulsions for cosmetic use, such as lotions and creams, are complex multiple-phase systems, which may contain a number of interacting surfactants, fatty amphiphiles, polymers and other excipients. This study investigates the influence of two synthetic cationic polymers, Polyquaternium-7 and Polyquaternium-11, and the natural anionic polymer, gum of acacia, on the rheology and microstructure of creams prepared with a non-ionic mixed emulsifier (cetyl stearyl alcohol-12EO/cetyl alcohol) using rheology (continuous shear, and viscoelastic creep and oscillation), microscopy and differential scanning calorimetry (DSC). A control cream containing no polymer was also investigated. The semisolid control cream was structured by a swollen lamellar gel network phase formed from the interaction of cetyl alcohol and the POE surfactant, in excess of that required to stabilize oil droplets, with continuous phase water. Endothermic transitions between 25 and 100 degrees C were identified as components of this phase. Incorporation of cationic polymer into the formulation caused significant loss of structure to produce a mobile semisolid containing larger oil droplets. The microscopical and thermal data implied that the cationic polymer caused the swollen lamellar gel network phase to transform into non-swollen crystals of cetyl alcohol. In contrast, incorporation of gum of acacia produced a thicker cream than the control, with smaller droplet sizes and little evidence of the gel network. Microscopical and thermal data implied that although there were also interactions between gum of acacia and both the surfactant and the swollen gel network phase, the semisolid properties were probably because of the ability of the gum of acacia to stabilize and thicken the emulsion in the absence of the swollen lamellar network.