Modificação química e física do amido de quirera de arroz para aproveitamento na indústria de alimentos

The study evaluated the efficiency of chemical (phosphorylation) and physical (extrusion) modifications of the starch of broken rice. Results demonstrated a reduction in the moisture content of extruded and phosphorylated broken rice and an increase in the ash content of phosphorylated broken rice. Both phosphorylation and extrusion increased cold water binding capacity, swelling power, and solubility. Extruded and phosphorylated pastes were stable under refrigeration, but only extruded paste was stable when submitted to freezing. Phosphorylated paste had the lowest viscosity and the highest stability during heating, while the extruded one gelatinized without heating, but had higher losses during heating.

Determination of moisture content and water activity in algae and fish by thermoanalytical techniques

The water content in seafoods is very important since it affects their sensorial quality, microbiological stability, physical characteristics and shelf life. In this study, thermoanalytical techniques were employed to develop a simple and accurate method to determine water content (moisture) by thermogravimetry (TG) and water activity from moisture content values and freezing point depression using differential scanning calorimetry (DSC). The precision of the results suggests that TG is a suitable technique to determine moisture content in biological samples. The average water content values for fish samples of Lutjanus synagris and Ocyurus chrysurus species were 76.4 ± 5.7% and 63.3 ± 3.9%, respectively, while that of Ulva lactuca marine algae species was 76.0 ± 4.4%. The method presented here was also successfully applied to determine water activity in two species of fish and six species of marine algae collected in the Atlantic coastal waters of Bahia, in Brazil. Water activity determined in fish samples ranged from 0.946 - 0.960 and was consistent with values reported in the literature, i.e., 0.9 - 1.0. The water activity values determined in marine algae samples lay within the interval of 0.974 - 0.979.

The pre-history of cryoscopy: what was done before raoult?

Cryoscopy is considered one of the foundations of the modern theory of solutions and of physical chemistry. This paper shows in order the first regularities pointed out by several scientists on the subject, in the first chapter of its birth as a scientific discipline. The study is focused on the identification of the different steps that helped, first qualitatively and then quantitatively, to adjust the different classes of possible solutions, including those that formed hydrates, to a basic formulation that the French scientist François-Marie Raoult would later generalize in the law that bears his name.

Caracterização da fusão peritética do cloreto de sódio di-hidratado por curvas de aquecimento

Binary mixture phase diagrams are normally obtained from thermal analysis involving freezing point curves. However, that approach is not always reliable and easy to follow to all kinds of mixtures in any proportion. In fact, even for a simple system, such as NaCl-H2O, this freezing methodology gives mixed results when one starts from a solid-solution system, due mostly to the formation of the NaCl.2H2O, which has an incongruent melting point, and the dependence of its solubility with the temperature. In this work we report a trustworthy, simple and cheap method involving heating curves to drawn the NaCl-H2O phase diagram.

Desenvolvimento de procedimento de extração para análise de sedativos e B-bloqueadores em rim suíno

A procedure was developed for determination of 5 sedatives and 14 β-blockers in swine kidney and subsequent analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Three different procedures for extraction were tested, evaluated through recovery studies. The procedure using acetonitrile for extraction and cleanup with freezing at low temperature and dispersive solid phase extraction using 500 mg celite® 545 before the concentration step presented the better results. The dried samples were redissolved with methanol and analyzed using a LC-MS/MS system with electrospray ionization (ESI) operating in positive MRM mode. The recovery values for this procedure were in the 75-88% range. The robustness of the method was tested against small variations. The method was used to analyze carazolol, azaperone and azaperol in collaborative assay, obtaining results close to designed value.

Optimization of chromatographic conditions and comparison of extraction efficiencies of four different methods for determination and quantification of pesticide content in bovine milk by UFLC-MS/MS

This paper describes the optimization of a multiresidue chromatographic analysis for the identification and quantification of 20 pesticides in bovine milk, including three carbamates, a carbamate oxime, six organophosphates, two strobilurins, a pyrethroid, an oxazolidinedione, an aryloxyphenoxypropionate acid/ester, a neonicotinoid, a dicarboximide, and three triazoles. The influences of different chromatographic columns and gradients were evaluated. Furthermore, four different extraction methods were evaluated; each utilized both different solvents, including ethyl acetate, methanol, and acetonitrile, and different workup steps. The best results were obtained by a modified QuEChERS method that lacked a workup step, and that included freezing the sample for 2 hours at -20 ºC. The results were satisfactory, yielding coefficients of variation of less than 20%, with the exception of the 50 µg L-1 sample of famoxadone, and recoveries between 70 and 120%, with the exception of acephate and bifenthrin; however, both analytes exhibited coefficients of variation of less than 20%.

Percutaneous core biopsy of palpable breast lesions: accuracy of frozen section histopathological exam in the diagnosis of breast cancer

OBJECTIVE: to evaluate the accuracy of frozen section histopathology from fragments of tissue obtained by percutaneous core needle biopsy of palpable tumors in the diagnosis of breast cancer. METHODS: a cohort study was performed on 57 patients with palpable tumors and suspected breast cancer undergoing percutaneous thick needle core biopsy. The fragments were analyzed by the same pathologist. RESULTS: frozen section diagnosed 16 benign cases (28.6%) and 40 malignant (71.4%), whereas paraffin showed that 15 were benign (26.8%) and 41 malignant (73.2%). Histopathological examinations were concordant in 55 cases and there was one false-negative (6.2%). Statistics rates were: negative predictive value of 93.8%, positive predictive value of 100%, no false-positive (0%), one false negative (6.2%), specificity of 100%, sensitivity of 97 6%; observed agreement = 98.2%; expected agreement = 59.9%, Kappa = 0.955 [ 95% CI = 0.925-0.974, p < 0.01 ]. CONCLUSIONS: frozen section histopathological findings showed excellent correlation with the findings by the technique in paraffin in the fragments of palpable breast tumors obtained by thick needle percutaneous core biopsy (98.2% accuracy). Therefore, in these patients, it was possible to anticipate the diagnosis, staging and the breast cancer treatment planning.

Distribution of immune response cells in the pelvic urethra and the prepuce of rams

The pathogens of the reproductive system in the male can penetrate and establish by ascending route, from to the prepuce to the urethra, accessory glands, epididymis and testicles. The aim of this paper is determine the distribution and number of cells involved in the immune response in prepuce and pelvic urethra of rams, without apparent clinical alterations in testicle, epididymis and prepuce. The distribution of some of the cells involved in the immune response at the level of the prepuce and the pelvic urethra was quantified in four one-year-old rams seronegative for B. ovis and A. seminis and without apparent lesions in the testicles, the epididymis, and the prepuce. At the moment of slaughter, samples were taken from the preputial fornix and the pelvic urethra and placed in 10% formalin and under freezing conditions. CD4, CD8, WC1, CD45RO, CD14 and CD1b cells were demonstrated by immunohistochemistry, and immunoglobulin-containing cells (ICC) of the IgA, IgG and IgM classes were demonstrated by immunofluorescence. The labeled cells present in the mucosa of both organs were counted with an image analyzer. The total number of cells was compared between both tissues and differentially between the epithelium and the connective tissue of the mucosa. Significant differences were found in the total number of CD4, CD45RO, and WC1 lymphocytes, in CD14 macrophages, and CD1b dendritic cells, with mean values being greater in the fornix than in the urethra (p<0.05) in all cases. Only dendritic cells were found in the prepuce. No differences were found in the number of CD8 lymphocytes between both organs. The ratio between each cell type in the connective and the intraepithelial tissues and between organs was 10/1 for CD4 in the fornix (p<0.05), against 7/1 in the urethra (p<0.05), while CD8 had a 1/1 distribution in both mucosae. The WC1 ratio was 5/1 in both mucosae (p<0.05). CD45RO labeling was 19/1 in the prepuce (p<0.05) and 1/1 in the urethra. IgA-containing cells did not show differences in the total number of cells in both tissues. In the urethra, no IgG-containing cells were observed and IgM-containing cells were scarce; in contrast, both cell types were present in the prepuce, in amounts greater than in the urethra (p<0.05). IgA-, IgG-, and IgM-containing cells were located in both organs in the mucosal connective tissue. The presence of antigen-presenting cells, macrophages, and dendritic cells, as well as of lymphocytes CD4, CD8 TCR γδ (WC1), IgA-, IgG and IgM positive cells, and CD45RO cells suggests that both mucosae may behave as inductive and effector sites for the mucosal immune response.

Isolation, expansion and differentiation of cellular progenitors obtained from dental pulp of agouti (Dasyprocta prymnolopha Wagler, 1831)

Abstract: The study aimed to isolate, expand, differentiate and characterize progenitor cells existent in the dental pulp of agouti. The material was washed with PBS solution and dissociated mechanically with the aid of a scalpel blade on plates containing culture medium D-MEM/F-12, and incubated at 5% CO2-37⁰C. The growth curve, CFU assay, osteogenic/adipogenic differentiation and characterization were obtained from the isolation. The cells began to be released from the explant tissue around the 7th day of culture. By day 22 of culture, cells reached 80% confluence. At the UFC test, 81 colonies were counted with 12 days of cultivation. The growth curves before and after freezing showed a regular growth with intense proliferation and clonogenic potential. The cell differentiation showed formation of osteoblasts and fat in culture, starting at 15 days of culture in a specific medium. Flow cytometry (FACs) was as follows: CD34 (positive), CD14 (negative), CD45 (negative), CD73 (positive), CD79 (negative), CD90 (positive), CD105 (positive), demonstrating high specificity and commitment of isolated cells with mesenchymal stem cells strains. These results suggest the existence of a cell population of stem cells with mesenchymal features from the isolated tissue in the explants of agouti dental pulp, a potential model for study of stem cell strains obtained from the pulp tissue.

Some biological aspects of the weed Lesser celandine (Ranunculus ficaria)

Lesser celandine (Ranunculaceae) is a perennial weed with tuberous root. Tubers are the most important means of reproduction and dispersion of this weed. In recent years, it has spread into wheat fields in Western Iran, mainly in the Lorestan province. A series of experiments were conducted to determine cardinal temperatures and to study the effects of pre-chilling, temperature fluctuations, tuber size, freezing and drying on germination of the tubers, as well as the effect of planting depth on sprouting of the tubers. The results obtained showed that the highest percentage of germination occurred when tubers were stored for more than 2 weeks at 4 or 8 ºC. The optimum temperature for germination differed in large and small tubers (8 and 14oC, respectively). Germination was the highest (almost 100%) at temperature fluctuations of 5-10oC. Germination of the finger-like and small tubers was the highest (95%); however, very small, small, and broken tubers showed the lowest germination percentage. In the freezing experiment, decreasing the temperature and increasing the storage duration decreased the germination of tubers. Increasing the osmotic potential and temperature resulted in decreased tuber germination of Lesser celandine. Lesser celandine could sprout down to 20 cm depth but heat demand for tubers from superficial depth was smaller than for tubers planted at greater depth.

Influence of lactation on motor activity and elevated plus maze behavior

Lactating rats show less noise-induced freezing and fewer inhibitory responses on the 6th day post-delivery when submitted to water and food deprivation in a classical conflict paradigm. Lactating mice go more often to the illuminated chamber in a light-dark cage and stay longer in it than virgin females. The present study was designed to assess the influence of this physiological state, i.e. lactation, on the elevated plus maze (EPM) and open-field behavior in adult female rats. Total (TL) and central (CL) locomotion and rearing (RF) frequencies were measured in an open-field. Number of entries into the open and closed arms as well as the time spent in each of these arms were measured in the EPM. Percent time spent and number of entries into the open arms were calculated and compared. In the open-field, TL was significantly decreased (115 ± 10.6 vs 150 ± 11.6) while CL and RF did not differ from those presented by virgin rats. In the EPM, lactating rats displayed a significant reduction in percent time spent (10.9 ± 1.5 vs 17.4 ± 2.3) in the open arms as well as a tendency to a reduction in percent entries into the open arms (35.7 ± 4.7 vs 45.7 ± 4.3). These results show that the physiological state of lactation modulates the open-field and EPM behaviors in rats

Paradoxical increase of exploratory behavior in the elevated plus-maze by rats exposed to two kinds of aversive stimuli

Albino rats were submitted to a 24-h period of social isolation (individual housing) combined with 0, 1, 2 or 3 twenty-four-hour periods of exposure to different vivaria (novelty) and tested in the elevated plus-maze. Results, reported as mean ± SEM for N = 12, show that the time (in seconds) spent in the open arms by rats exposed to novelty for 0, 1, 2 and 3 days was 28.3 ± 4.4, 31.6 ± 3.2, 29.1 ± 3.5 and 25.0 ± 3.3, respectively, when grouped in the same vivarium; 29.6 ± 2.7, 7.6 ± 2.1, 9.6 ± 4.4 and 28.5 ± 3.7 when grouped in different vivaria; 2.9 ± 1.1, 1.8 ± 1.0, 2.7 ± 1.1 and 0 ± 0 when isolated in the same vivarium, and 2.6 ± 1.1, 31.5 ± 8.2, 24.8 ± 4.2 and 0 ± 0 when isolated in different vivaria. The number of entries into the open and closed arms followed a similar trend. This indicates that, separately, both exposure to novelty and isolation are aversive manipulations. Paradoxically, when novelty was combined with a concomitant 24-h period of social isolation prior to testing, the decrease in exploratory behavior caused by either of the two aversive manipulations alone was reverted. These results are indicative that less intense anxiety triggers mechanisms mediating less energetic behavior such as freezing, while higher levels trigger mechanisms mediating more vigorous action, such as flight/fight behavior, since the combination of two aversive situations resulted in more exploratory behavior than with either alone. They are also suggestive of habituation to the effects of novelty, since exposure to it for 3 days produced exploratory behavior similar to that of controls

Techniques of radioautography for medical and biological research

Standard techniques for radioautography used in biological and medical research can be classified into three categories, i.e., macroscopic radioautography, light microscopic radioautography and electron microscopic radioautography. The routine techniques used in these three procedures are described. With regard to macroscopic radioautography, whole body radioautography is a standard technique which employs freezing and cryosectioning and can demonstrate organ distributions of both soluble and insoluble compounds. In contrast, in light and electron microscopic radioautography, soluble and insoluble techniques are separated. In order to demonstrate insoluble labeled compounds, conventional chemical fixations such as formalin for light microscopy or buffered glutaraldehyde and osmium tetroxide for both light and electron microscopy followed by dehydration, embedding and wet-mounting applications of radioautographic emulsions can be used. For the demonstration of soluble labeled compounds, however, cryotechniques such as cryofixation, cryosectioning, freeze-drying, freeze-substitution followed by dry-sectioning and dry-mounting radioautography should be employed both for light and electron microscopy. The outlines of these techniques, which should be utilized in various fields of biological and medical research, are described in detail

Anterograde effects of a single electroconvulsive shock on inhibitory avoidance and on cued fear conditioning

A single electroconvulsive shock (ECS) or a sham ECS was administered to male 3-4-month-old Wistar rats 1, 2, and 4 h before training in an inhibitory avoidance test and in cued classical fear conditioning (measured by means of freezing time in a new environment). ECS impaired inhibitory avoidance at all times and, at 1 or 2 h before training, reduced freezing time before and after re-presentation of the ECS. These results are interpreted as a transient conditioned stimulus (CS)-induced anxiolytic or analgesic effect lasting about 2 h after a single treatment, in addition to the known amnesic effect of the stimulus. This suggests that the effect of anterograde learning impairment is demonstrated unequivocally only when the analgesic/anxiolytic effect is over (about 4 h after ECS administration) and that this impairment of learning is selective, affecting inhibitory avoidance but not classical fear conditioning to a discrete stimulus.

Role of the hippocampus in contextual memory after classical aversive conditioning in pigeons (C. livia)

We investigated the effects of hippocampal lesions with ibotenic acid (IBO) on the memory of the sound-context-shock association during reexposure to the conditioning context. Twenty-nine adult pigeons were assigned to a non-lesioned control group (CG, N = 7), a sham-lesioned group (SG, N = 7), a hippocampus-lesioned experimental group (EG, N = 7), and to an unpaired nonlesioned group (tone-alone exposure) (NG, N = 8). All pigeons were submitted to a 20-min session in the conditioning chamber with three associations of sound (1000 Hz, 85 dB, 1 s) and shock (10 mA, 1 s). Experimental and sham lesions were performed 24 h later (EG and SG) when EG birds received three bilateral injections (anteroposterior (A), 4.5, 5.25 and 7.0) of IBO (1 µl and 1 µg/µl) and SG received one bilateral injection (A, 5.25) of PBS. The animals were reexposed to the training context 5 days after the lesion. Behavior was videotaped for 20 min and analyzed at 30-s intervals. A significantly higher percent rating of immobility was observed for CG (median, 95.1; range, 79.2 to 100.0) and SG (median, 90.0; range, 69.6 to 95.0) compared to EG (median, 11.62; range, 3.83 to 50.1) and NG (median, 7.33; range, 6.2 to 28.1) (P<0.001) in the training context. These results suggest impairment of contextual fear in birds who received lesions one day after conditioning and a role for the hippocampus in the modulation of emotional aversive memories in pigeons.