Identification of a high molecular weight polypeptide in the subcommissural organ of the chick embryo

The subcommissural organ is an ependymal brain gland that secretes, into the ventricular cerebrospinal fluid, high molecular weight glycoproteins that form Reissner's fiber. Precursor and processed forms of secretion have been demonstrated by immunoblotting in the subcommissural organ of mammals and fish. In the chicken only a processed form has as yet been identified. In the present report, we have studied the subcommissural organ of 13-day-old chick embryos using (1) an antiserum against bovine Reissner's fiber, and (2) the lectins, concanavalin A and Limax flavus agglutinin. Paraffin sections of the subcommissural organ and blots of subcommissural organ extracts have been analyzed. The ependymal cells of sectioned subcommissural organ are strongly stained with the antiserum. Concanavalin A binds to materials in all cytoplasmatic regions, whereas Limax flavus agglutinin identifies materials confined to the apex of the ependymal cells. In the blots, a band of 540 kDa is immunostained. This band is positive for concanavalin A positive but negative for Limax flavus agglutinin and is thereby regarded as representing a precursor form of the secretion.     

Quantitation of active ingredients and excipients in nasal sprays by high-performance liquid chromatography, capillary electrophoresis and UV spectroscopy

A study on the use of different analytical methodologies to determine active ingredients and excipients found in commercial nasal sprays is presented. Two of the developed methodologies consisted of separation techniques, i.e. high-performance liquid chromatography and capillary electrophoresis, and the third one involved a UV-spectroscopic multicomponent procedure. The samples studied are characterized by a high viscosity and the existence of a large number of particles in suspension; therefore, special emphasis is paid on the sample preparation required by each methodology. Advantages and drawbacks of each analytical technique are also discussed in terms of speed of analysis, sensitivity and reproducibility. From this work it is observed that although the UV method needs the most laborious sample preparation, the total time required per analysis is the shortest one. The best reproducibility in terms of analysis time and quantitation of the analyzed compounds is obtained using HPLC. CE allows the determination of more components in the same sample.     

Epidemic outbreak in a home for the aged caused probably by Bacillus cereus

OBJECTIVES: To identify the causative agent and the factors precipitating the outbreak. DESIGN: Observational, crossover study. SETTING: Las Delicias Health district, Jerez de la Frontera. PATIENTS AND OTHER PARTICIPANTS: The population exposed, belonging to an elderly persons' home. MEASUREMENTS AND MAIN RESULTS: The total number of people exposed was the 425 persons living in an elderly persons' home in Jerez in November 1995. The clinical histories were reviewed, and a specific questionnaire used to interview 77 ill persons and 77 healthy ones. The criteria for ill cases were presence of vomiting and/or diarrhoea. 32.6% of the ill people had fundamentally vomiting; 24.67% diarrhoea, 37.66% vomiting plus diarrhoea, and 100% ran no temperature. Positive and significant OR were detected in various foods (from 2.36 to 10.52 OR). We isolated 3,000,000, and up to 5,600,000, colonies of Bacillus cereus per gram in several foods. We observed incorrect practices in the conservation and handling of foods. CONCLUSIONS: Epidemiological, microbiological and clinical indications placed us before an outbreak of food poisoning probably caused by Bacillus cereus. The intervention at critical points, inter-institution coordination and communication in time and with data between professionals (microbiologist, doctors, nurses, vets and epidemiologist) were decisive in solving the outbreak.     

MS-based analytical methodologies to characterize genetically modified crops

The development of genetically modified crops has had a great impact on the agriculture and food industries. However, the development of any genetically modified organism (GMO) requires the application of analytical procedures to confirm the equivalence of the GMO compared to its isogenic non-transgenic counterpart. Moreover, the use of GMOs in foods and agriculture faces numerous criticisms from consumers and ecological organizations that have led some countries to regulate their production, growth, and commercialization. These regulations have brought about the need of new and more powerful analytical methods to face the complexity of this topic. In this regard, MS-based technologies are increasingly used for GMOs analysis to provide very useful information on GMO composition (e.g., metabolites, proteins). This review focuses on the MS-based analytical methodologies used to characterize genetically modified crops (also called transgenic crops). First, an overview on genetically modified crops development is provided, together with the main difficulties of their analysis. Next, the different MS-based analytical approaches applied to characterize GM crops are critically discussed, and include "-omics" approaches and target-based approaches. These methodologies allow the study of intended and unintended effects that result from the genetic transformation. This information is considered to be essential to corroborate (or not) the equivalence of the GM crop with its isogenic non-transgenic counterpart.     

Chiral nano-liquid chromatography–mass spectrometry applied to amino acids analysis for orange juice profiling

Determination of amino acid enantiomers is a very important topic in food analysis, since the presence of d-isomers may indicate, e.g., adulteration, microbiological contamination, uncontrolled fermentation processes, etc. In fact, the d- and l-enantiomers contents can be a useful marker for several elements such as quality control, contamination detection, processing monitoring, etc. Here we studied the potentiality of nano-liquid chromatography (nano-LC) coupled with mass spectrometry for the enantiomeric separation of several d- and l-amino acids that can be found in food products. Analytes were derivatized with fluorescein isothiocyanate (FITC). The mixture was injected and compounds focused on a C18 cartridge, then nano-LC analysis was carried out in a capillary column (75 μm i.d.) packed with vancomycin-modified silica–diol particles. The effect of some experimental parameters, such as pH and buffer concentration on enantioresolution and retention factors, was studied for method optimization. The chromatographic separation system was coupled with an ion-trap mass spectrometer through a nano spray interface. It provided a final evaluation on analytes detected in all investigated samples with LOD values as low as 8 ng/mL. That method was applied to the comparative analysis of two different orange juice samples (fresh natural vs. commercial one). Obtained profiles confirmed expected high quality standards. In fact, they mainly contained l-amino acids forms and not their antipodes.     

Enhancement of mechanical properties of aluminium/epoxy composites with silane functionalization of aluminium powder

In this study, the effect of surface modification of aluminum powders on the tensile, fracture, and tribological behaviors of aluminum/epoxy composites was investigated. Aluminum powders were surface-modified with 3-aminopropyltriethoxysilane. Aluminium/epoxy composites were fabricated by cast molding method using 10 wt.% untreated and silane-treated aluminium powders. Tensile, mode I fracture, and tribological tests were performed on both composites. The results showed that the tensile modulus and strength of silane-treated aluminum/epoxy composites were ～9% and ～12% greater, respectively than those of untreated aluminum/epoxy composites. The results also showed that the fracture toughness and wear resistance of silane-treated aluminum/epoxy composites were ～32% and ～56% greater than that of untreated aluminum/epoxy composites. Scanning electron microscope (SEM) examination showed the improvement of tensile and fracture properties of silane-treated aluminum/epoxy composites was attributed to the improved dispersion and bonding of aluminum particles in the epoxy, due to the silanization of aluminium powders.     

Spontaneous congenital hydrocephalus in the mutant mouse hyh. Changes in the ventricular system and the subcommissural organ

Like neutrophils, Epstein-Barr virus (EBV)-immortalized B lymphocytes express all constituents of the NADPH oxidase complex necessary to generate superoxide anion O2-. The NADPH oxidase activity in EBV-B lymphocytes is only 5% of that measured in neutrophils upon PMA stimulation. Cytochrome b558 is the sole redox membrane component of NADPH oxidase; it is the protein core around which cytosolic factors assemble in order to mediate oxidase activity. In the present study, we have compared the structural and functional properties of cytochrome b558 from EBV-B lymphocytes and neutrophils. Cytochrome b558 from EBV-B lymphocyte plasma membrane, like that from neutrophils, is characterized by a heterodimeric structure with a highly glycosylated beta subunit, known as gp91-phox. While the amount of cytochrome b558 recovered after purification from EBV-B lymphocytes (approximately 0.24 nmol from 1010 cells) was low compared to that recovered from neutrophils (approximately 10 nmol), the biochemical properties of purified cytochrome b558 from both EBV-B lymphocytes and neutrophils were quite similar with respect to their differential spectra, redox potential, and FAD binding site. Once cytochrome b558 was extracted from the EBV-B lymphocyte membrane, it was able to mediate, in a reconstituted system of O2- production the same oxidase turnover as that found for cytochrome b558 extracted from neutrophils. A comparison between membrane bound and soluble cytochrome b558 suggested that the weak oxidase activity measured in intact EBV-B cells might be the result not only of the small amount of expressed cytochrome b558, but also of a defect of the activation process in lymphocyte membrane.     

Dynamic analysis of runout correction in milling

Tool runout and its effects is an important area of research within modelling, simulation, and control of milling forces. Tool runout causes tool cutting edges to experience uneven forces during milling. This fact also affects tool life and deteriorates workpiece surface quality. In this article a procedure, in order to diminish the effects of tool runout, is presented. The procedure is based on chip thickness modification by means of the fast correction of the tool feed rate. Dynamic feed rate modification is provided by superposing our own design of a fast feed system driven by a piezoelectric actuator to the conventional feed drive of the CNC machine tool. Previously, a model of the dynamic behaviour of the system was developed to analyze the influence of fast feed rate modification on cutting forces. The model incorporates the piezoelectric actuator response as well as the structural dynamics of the tool and the designed Fast Feed Drive System (FFDS). Simulated and experimental results presented in this paper show the effectiveness and benefits of this new tool runout correction procedure.     

Recovery of jump table case statements from binary code

One of the fundamental problems with the static analysis of binary (executable) code is that of recognizing, in a machine-independent way, the target addresses of n-conditional branches implemented via a jump table. Without these addresses, the decoding of the machine instructions for a given procedure is incomplete, leading to imprecise analysis of the code.

In this paper we present a technique for recovering jump tables and their target addresses in a machine and compiler independent way. The technique is based on slicing and copy propagation. The assembly code of a procedure that contains an indexed jump is transformed into a normal form which allows us to determine where the jump table is located and what information it contains (e.g. offsets from the table or absolute addresses).

The presented technique has been implemented and tested on SPARC and Pentium code generated by C, C++, Fortran and Pascal compilers. Our tests show that up to 89% more of the code in a text segment can be found by using this technique, when compared against the standard method of decoding. The technique was developed as part of our retargetable binary translation framework UQBT; however, it is also suitable for other binary-manipulation and analysis tools such as binary profilers, instrumentors and decompilers.     

Paternity study applying DNA polymorphism: evaluation of methods traditionally used in Chile

Simultaneous detection of several VNTR loci using a single DNA probe is the basis of the technique called "DNA fingerprint" (DNAfp) of increasing application in parenthood identification. According to the data gathered by different laboratories worldwide, father exclusion can be made in a larger number of cases when compared with the customary tests based on erythrocyte antigens. The question could then be whether DNAfp will completely replace erythrocyte antigens tests. We report here our experience in applying DNAfp to 92 samples corresponding to 34 paternity cases and comparing these with the results obtained with the antigens of the systems ABO, Rh, MNSs, Duffy and Kidd. Most of the HaeIII/digested DNA samples produced 13 to 16 bands larger than 4.3 Kb (average 14,0761 +/- 2,205). Average band sharing between pairs of unrelated individual was 1,9107 +/- 1,083. Two cases presenting an a posteriori probability of being the father of 80.7% and 76.5% by erythrocyte antigens were clearly excluded by DNAfp. All exclusions made by antigens were confirmed by DNAfp. In the cases reported as father "rather probable" (28 cases) by DNAfp, these shared with the child 6,7407 +/- 1.7 bands on average. Because of time, cost and simplicity we favor a procedure starting with the antigens test and continuing with DNAfp only when an exclusion is not possible. Economy will increase as the number of exclusions increases.