PubMed Health⌕ Search

Biomedical subjects

L R Santos

Publications and source records attributed to L R Santos.

9 recordsLinked to original sources
PubMed2002

Detection and identification of salmonellas from poultry-related samples by PCR.

A polymerase chain reaction (PCR) assay was developed for the generic detection of Salmonella sp. and the identification of S. Enteritidis (SE), S. Gallinarum (SG), S. Pullorum (SP) and S. Typhimurium (ST) in material collected in the field from poultry. The specificity and sensitivity of the assay combined with Rappaport-Vassiliadis selective enrichment broth (PCR-RV) were determined, and field samples were analyzed to verify the validity of the method application. Specificity of the assay was tested using 29 SE, 11 SG, 10 ST and 10 SP strains, along with 75 strains of 28 other Salmonella serovars and 21 strains of other bacterial genera. The assay was 100% specific for Salmonella detection and ST identification. The primer pair for SE, SG and SP also detected S. Berta. PCR detection limits for Salmonella at the genus level were 2 ST, 8 SE, 1.1x10(3) SG and 1.8x10(5) SP cells. At the serovar level, detection limits were 7 ST, 1.2x10(3) SE, 4.4x10(7) SG and 1.8x10(6) SP cells. At the genus level, PCR-RV detected approximately 128% more positive field samples than the standard microbiological techniques and results were ready in 48h instead of 7 days. PCR-RV method is diagnostic of Salmonella at the genus level and ST at the serovar level, although other tests are needed to identify SE, SG and SP to serovar level.

Animals↗
PubMed2001

Visual representation in the wild: how rhesus monkeys parse objects.

Visual object representation was studied in free-ranging rhesus monkeys. To facilitate comparison with humans, and to provide a new tool for neurophysiologists, we used a looking time procedure originally developed for studies of human infants. Monkeys' looking times were measured to displays with one or two distinct objects, separated or together, stationary or moving. Results indicate that rhesus monkeys used featural information to parse the displays into distinct objects, and they found events in which distinct objects moved together more novel or unnatural than events in which distinct objects moved separately. These findings show both commonalities and contrasts with those obtained from human infants. We discuss their implications for the development and neural mechanisms of higher-level vision.

Animals↗
PubMed2001

Recognition and categorization of biologically significant objects by rhesus monkeys (Macaca mulatta): the domain of food.

To survive, organisms must be able to identify edible objects. However, we know relatively little about how humans and other species distinguish food items from non-food items. We tested the abilities of semi-free-ranging rhesus monkeys (Macaca mulatta) to learn rapidly that a novel object was edible, and to generalize their learning to other objects, in a spontaneous choice task. Adult monkeys watched as a human experimenter first pretended to eat one of two novel objects and then placed replicas of the objects at widely separated locations. Monkeys selectively approached the object that the experimenter had previously eaten, exhibiting a rapidly induced preference for the apparently edible object. In further experiments in which the same objects were used as tools or were manipulated at the face but not eaten, we fail to observe an approach bias, providing evidence that the monkeys' pattern of approach in the earlier experiments was specific to objects that were eaten. Subsequent experiments tested how monkeys generalized their preference for an edible object by first allowing them to watch a human experimenter eat one of two objects and then presenting them with new objects composed of the same substance but differing from the original, edible object in shape or color. Monkeys ignored changes in the shape of the object and generalized from one edible object to another on the basis of color in conjunction with other substance properties. Finally, we extended this work to infant rhesus monkeys and found that, like adults, they too used color to generalize to novel food objects. In contrast to adults, however, infants extended this pattern of generalization to objects that were acted on in other ways. These results suggest that infant monkeys form broader object categories than adults, and that food categories become sharpened as a function of maturational or experiential factors.

Age Factors↗
PubMed1999

In vitro and in vivo toxicological study of the Pterodon pubescens seed oil.

The oil of Pterodon pubescens seeds (PpSO) is known for its cercaricidal and anti-inflammatory effects. Its anti-rheumatic activity was recently reported using mice with collagen II-induced arthritis treated with a hydroalcoholic extract of PpSO, mimicking the wine infusion used in popular medicine. In the present study, PpSO was tested for acute toxicity, mutagenic activity and cytotoxicity for human peripheral blood mononuclear cells (PBMNC). PpSO was obtained after seed extraction with 100% ethanol and evaporation. Cytotoxicity was estimated using the tetrazolium salt reduction test (MTT assay) by PBMNC (2.5 x 10(5) cells/ml) after exposure to 0.07, 0.7 and 7 microg PpSO/ml for 24 and 48 h. In the mutagenesis assay, the Salmonella/mammalian microsome assay was employed with or without metabolization. Acute toxicity was studied on 30 (n = 10/group) male DBA1/J mice (20 +/- 2 g) after a single oral dose of 2, 4, and 8 g PpSO/kg b.w. The animals were observed for 24 h, anesthetized, sacrificed and autopsied. The organs were processed for histopathology by staining with hematoxylin-eosin. The IC50 of PpSO to PBMNC in RPMI 1640 supplemented with 5% fetal calf serum (FCS) was 2 and 1 microg PpSO/ml after 24 and 48 h, respectively. The mutagenic test performed with or without metabolic activation of PpSO did not show mutagenic activity for the concentrations tested (7 and 70 microg/ml). Mouse mortality or significant signs of acute toxicity (ocular, cardiovascular, gastrointestinal, motor or respiratory signs) for the PpSO doses tested was not observed. The organs did not show any macroscopic alterations. Histopathologic analysis of the tissues also did not demonstrate any lesions. The present study provides data to classify PpSO as non-cytotoxic to PBMNC, non-mutagenic, and non-toxic after acute administration since the PpSO doses tested were extremely higher than those used by the population.

Animals↗
PubMed1988

Purification and properties of peroxidase from Pinus pinaster needles.

Peroxidase (Ec 1.11.1.7) was purified from needles of Pinus pinaster to apparent homogeneity by DE-52 cellulose chromatography with a final recovery of enzyme activity of about 85%. The purified enzyme (A402/A275 = 1.05) had a specific activity of about 948 U/mg of protein and ran as a single protein band both on SDS-PAGE and native PAGE with Mr of 37,000 and 151,000, respectively. Both native PAGE and isoelectric focusing gels of the purified enzyme were stained for activity which coincided with the protein band. The pI of the purified enzyme was found to be 3.2 by isoelectric focusing on an ultrathin polyacrylamide gel. The enzyme has an optimum pH of activity of 5.0 and temperature optimum of 30 degrees C. Stability studies of the enzyme as a function of pH and temperature suggest that it is most stable at pH 5.0 and 0-40 degrees C, respectively.

Chromatography, Ion Exchange↗
PubMedDate not supplied

[The job of the hospital nurse: self-care and caring for others].

The self-care of nurses is a requirement for the care of the patient, so that the care provided will not imply on the resignation of the nursing professional or the client. The objective of the present study is to verify how the work of hospital nurses has been done, regarding the self-care of these professionals and the care provided to patients. Semi-structured interviews were carried out with nurses from two different districts in Rio Grande do Sul, who had graduated from public universities in the same state and worked in hospitals of the respective districts. Results showed that these professionals expressed the need of taking care of themselves in order to provide care for their patients. It was also reported that nurses assume responsibilities of other professionals and lack, in their professional environment, human and material resources. This situation generates negative consequences for the nurse's self-care, as well as for the care of the patients. It is important that nursing professionals implement strategies to deal with asymmetric power relations in the hospital, based on their beliefs, values and knowledge. This can lead to more appropriate conditions of work, which can guarantee a more qualified self-care of the professional, and a better care for the patient.

Activities of Daily Living↗
PubMedDate not supplied

The importance of the ligation of the inferior thyroid artery in parathyroid function after subtotal thyroidectomy.

UNLABELLED: We prospectively studied the effects of the ligation of the inferior thyroid artery (ITA) on postoperative hypoparathyroidism in 48 patients who underwent functional subtotal thyroidectomy. Patients were randomized into two groups: A, with bilateral ligation of the ITA and B, without ligation of the ITA. Parathyroid function was checked preoperatively and after surgery by clinical examination and measurement of total calcium, intact PTH, urinary calcium, and AMPc. RESULTS: A significant incidence of postoperative hypocalcemia occurred: 17% in group A and 13% in B on the 4th postoperative day. Six months later, the incidence was 5% in Group A and 0% in Group B. These differences were not statistically significant between the two groups, and neither were any of the other clinical and laboratory observations. CONCLUSION: The ligation of the ITA was not an important causal factor for the occurrence of postoperative hypocalcemia after subtotal thyroidectomy.

Adult↗