Ultrastructural characterization of CD133+ stem cells bound to superparamagnetic nanoparticles: possible biotechnological applications.

CD133 antigen is an integral membrane glycoprotein that can bind with different cells. Originally, however, this cellular surface antigen was expressed in human stem cells and in various cellular progenitors of the haematopoietic system. Human cord blood has been described as an excellent source of CD133(+) haematopoietic progenitor cells with a large application potential. One of the main objectives of the present study is to describe for the first time the ultrastructural characteristics of CD133(+) stem cells using transmission electronic microscopy. Another objective of the manuscript is to demonstrate through transmission electronic microscopy the molecular image of magnetic nanoparticles connected to the stem cells of great biotechnological importance, as well as demonstrating the value of this finding for electronic paramagnetic resonance and its related nanobioscientific value. Ultrastructural results showed the monoclonal antibody anti-CD133 bound to the superparamagnetic nanoparticles by the presence of electrondense granules in cell membrane, as well as in the cytoplasm, revealing the ultrastructural characteristics of CD133(+) cells, exhibiting a round morphology with discrete cytoplasmic projections, having an active nucleus that follows this morphology. The cellular cytoplasm was filled up with mitochondrias, as well as microtubules and vesicles pinocitic, characterizing the process as being related to internalization of the magnetic nanoparticles that were endocyted by the cells in question. Electronic paramagnetic resonance analysis of the CD133(+) stem cells detected that the signal (spectrum) generated by the labelled cells comes from the superparamagnetic nanoparticles that are bound to them. These results strongly suggest that these CD133(+) cells can be used in nanobiotechnology applications, with benefits in different biomedical areas.

Patterns of cerebral activation during lexical and phonological reading in Portuguese

According to the concepts of cognitive neuropsychology, there are two principal routes of reading processing: a lexical route, in which global reading of words occurs and a phonological route, responsible for the conversion of the graphemes into their respective phonemes. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the patterns of cerebral activation in lexical and phonological reading by 13 healthy women with a formal educational level greater than 11 years. Participants were submitted to a silent reading task containing three types of stimuli: real words (irregular and foreign words), nonwords and illegitimate graphic stimuli. An increased number of activated voxels were identified by fMRI in the word reading (lexical processing) than in the nonword reading (phonological processing) task. In word reading, activation was greater than for nonwords in the following areas: superior, middle and inferior frontal gyri, and bilateral superior temporal gyrus, right cerebellum and the left precentral gyrus, as indicated by fMRI. In the reading of nonwords, the activation was predominant in the right cerebellum and in the left superior temporal gyrus. The results of the present study suggest the existence of differences in the patterns of cerebral activation during lexical and phonological reading, with greater involvement of the right hemisphere in reading words than nonwords.

Utility of computerized morphometry combined with AgNOR staining in distinguishing benign from malignant pleural effusions.

A study was designed to evaluate the usefulness of computer-aided image analysis in distinguishing benign from malignant pleural effusions. Morphometric measurements of preparations stained by the routine Leishman technique and quantitation of nucleolar organizer regions (AgNORs) were done on 65 cytologic samples randomly selected for the study and divided as follows: 30 samples from patients having benign pleural cytology and 35 samples from patients with pleural malignancies. The following parameters were obtained: nuclear/cytoplasmic ratio (N/C); nuclear and cytoplasmic area (NA and CA, respectively) and perimeter (NP and CP, respectively); major and minor nuclear diameter (DN and dN, respectively); major and minor cytoplasmic diameter (DC and dC, respectively); and absolute and fractional AgNOR (AgNOR/NA) area. Conformational characteristics of both nucleus (FFN) and cytoplasm (FFCy) were also computed. Statistical studies were done by means of discriminant analysis. The discriminant function generated from the morphometric data correctly diagnosed 100% of the cases. The validity of the classification provided by the function was tested by a jack knife ("one out" procedure), which again classified all the cases correctly. Our data support the concept that quantitative morphologic studies could be used in the management of patients with pleural effusions.

Quantitative pathology of nasal passages in rats exposed to urban levels of air pollution.

In order to assess the adverse effects of urban levels of air pollution, rats were used as biological indicators in a chronic exposure experiment. Animals were housed for 6 months in the center of São Paulo (the largest South American town) and compared to controls kept for the same period in a clean area. Pollution levels were obtained from a state air pollution monitoring station, 200 m distant from exposure location, which provided the levels of CO, SO2, particulates, and ozone. The nasal septum was submitted to quantitative analysis of morphological and histochemical parameters, comprising the measurement of volume of epithelium and lamina propria per unity of surface of basal lamina, the amount of mucus stored in the surface epithelium, the volume densities of neutral and acidic mucus in the lamina propria glands, and the densities of secretory and ciliated cells in the epithelium. The results obtained in the present investigation suggest that chronic exposure to urban levels of air pollution induces secretory hypertrophy, combined with a shift toward acidic mucus secretion and ciliary damage. The results are consistent with the idea that prolonged exposure to low levels of air pollution deteriorates respiratory defenses against infectious agents and may cause an increase in respiratory morbidity and perhaps mortality.