The effect on hemolysis of the raceway profile of roller pumps used in cardiopulmonary bypass

This study aims at the influence on hemolysis of the differences between the maximum and minimum amplitudes of pressure in the outlet of three roller pump models adjusted by dynamic calibration method. Tests were performed with silicone tubes (? × (3)/(16) inches) in fluid analogous to blood and fresh bovine blood from slaughterhouse. Tests with analogous solution to blood were performed varying the dynamic calibration pressure between 78 and 500 mm Hg. Tests with fresh bovine blood were performed with the three pumps simultaneously, and pressure differences and free hemoglobin in the plasma were measured during 360 minutes. Tests with both analogous solution to blood and fresh bovine blood showed differences of mean pressures of pump 2 related to pumps 1 and 3 (p < 0.01). The different models of roller pumps analyzed presented differences in pressure amplitudes (p < 0.01) and hemolysis (p < 0.01) adjusted for the same dynamic calibration pressure. Raceway profile of pump 2 resulted in smaller pressure amplitude, implying lower hemolysis rate compared with pumps 1 and 3.     

Leishmania major-like antigen for specific and sensitive serodiagnosis of human and canine visceral leishmaniasis

An antigen (LMS) prepared from Leishmania major-like promastigotes was used in an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of human and dog visceral leishmaniasis. The results were compared with those from the indirect immunofluorescent antibody test (IFAT). A total of 1822 canine sera were tested, including sera from dogs with visceral leishmaniasis, transmissible venereal tumors, ehrlichiosis, rickettsiosis, or Chagas' disease and sera from healthy dogs. The antigen was also tested with 227 samples of human sera, including sera from patients with visceral, cutaneous, or diffuse cutaneous leishmaniasis and from noninfected individuals, as well as sera from patients with Chagas' disease, toxoplasmosis, rickettsiosis, hepatitis B, schistosomiasis, ascaridiasis, malaria, rheumatoid factor, leprosy and rheumatoid factor, tuberculosis, or leprosy. All dogs and all human patients had a clinical and/or serological and/or parasitological diagnosis. For detecting antibodies in sera from dogs with leishmaniasis, the antigen showed a sensitivity of 98%, specificity of 95%, and concordance of 93% and when used for detecting antibodies in human sera presented a sensitivity of 92%, specificity of 100%, and concordance of 92%. Comparison between ELISA and IFAT demonstrated that ELISA using the LMS antigen yielded more reliable results than IFAT. The LMS antigen displayed no cross-reactivity with sera from patients or dogs that had any of the other diseases tested.     

Evaluation of the Clinical Anatomy Program in the Medical School of Porto by two cohorts of students

The discipline of Clinical Anatomy, as introduced in the Medical School of Porto in academic year 1995/96, involved major changes in the way we teach anatomy to medical students, by adopting a clinically oriented approach. A questionnaire was designed to evaluate the opinion of second-year medical students enrolled in the program concerning main aspects of the discipline in two consecutive years; 84% of the students returned the questionnaire in 1996/97, and 70% in 1997/98. Students were asked about the level of their approval of the organization of the discipline, the role of the teaching staff, lectures, practical sessions, educational media, and continuous and summative assessments. For items replicated in both academic years, the means of the sum of scores in each year were compared (Student's t-distribution). Whenever a significant difference was found, changes in individual items were tested (chi-square distribution). The evaluation of the discipline in each of the two years was highly favorable for most of the parameters analyzed.     

Bacille Calmette–Guérin/DNAhsp65 prime‐boost is protective against diabetes in non‐obese diabetic mice but not in the streptozotocin model of type 1 diabetes

Type I diabetes is a disease caused by autoimmune destruction of the beta cells in the pancreas that leads to a deficiency in insulin production. The aim of this study was to evaluate the prophylactic potential of a prime‐boost strategy involving bacille Calmette–Guérin (BCG) and the pVAXhsp65 vaccine (BCG/DNAhsp65) in diabetes induced by streptozotocin (STZ) in C57BL/6 mice and also in spontaneous type 1 diabetes in non‐obese diabetic (NOD) mice. BCG/DNAhsp65 vaccination in NOD mice determined weight gain, protection against hyperglycaemia, decreased islet inflammation, higher levels of cytokine production by the spleen and a reduced number of regulatory T cells in the spleen compared with non‐immunized NOD mice. In the STZ model, however, there was no significant difference in the clinical parameters. Although this vaccination strategy did not protect mice in the STZ model, it was very effective in NOD mice. This is the first report demonstrating that a prime‐boost strategy could be explored as an immunomodulatory procedure in autoimmune diseases.     

DO SEMANTIC CATEGORIES ACTIVATE DISTINCT CORTICAL REGIONS? EVIDENCE FOR A DISTRIBUTED NEURAL SEMANTIC SYSTEM

A key issue in cognitive neuroscience concerns the neural representation of conceptual knowledge. Currently, debate focuses around the issue of whether there are neural regions specialised for the processing of specific semantic attributes or categories, or whether concepts are represented in an undifferentiated neural system. Neuropsychological studies of patients with selective semantic deficits and previous neuroimaging studies do not unequivocally support either account. We carried out a PET study to determine whether there is any regional specialisation for the processing of concepts from different semantic categories using picture stimuli and a semantic categorisation task. We found robust activation of a large semantic network extending from left inferior frontal cortex into the inferior temporal lobe and including occipital cortex and the fusiform gyrus. The only category effect that we found was additional activation for animals in the right occipital cortex, which we interpret as being due to the extra visual processing demands required in order to differentiate one animal from another. We also carried out analyses in specific cortical regions that have been claimed to be preferentially activated for various categories, but found no evidence of any differential activation as a function of category. We interpret these data within the framework of cognitive accounts in which conceptual knowledge is represented within a nondifferentiated distributed system.     

Enhanced spatio-temporal alignment of plantar pressure image sequences using B-splines

This article presents an enhanced methodology to align plantar pressure image sequences simultaneously in time and space. The temporal alignment of the sequences is accomplished using B-splines in the time modeling, and the spatial alignment can be attained using several geometric transformation models. The methodology was tested on a dataset of 156 real plantar pressure image sequences (3 sequences for each foot of the 26 subjects) that was acquired using a common commercial plate during barefoot walking. In the alignment of image sequences that were synthetically deformed both in time and space, an outstanding accuracy was achieved with the cubic B-splines. This accuracy was significantly better (p < 0.001) than the one obtained using the best solution proposed in our previous work. When applied to align real image sequences with unknown transformation involved, the alignment based on cubic B-splines also achieved superior results than our previous methodology (p < 0.001). The consequences of the temporal alignment on the dynamic center of pressure (COP) displacement was also assessed by computing the intraclass correlation coefficients (ICC) before and after the temporal alignment of the three image sequence trials of each foot of the associated subject at six time instants. The results showed that, generally, the ICCs related to the medio-lateral COP displacement were greater when the sequences were temporally aligned than the ICCs of the original sequences. Based on the experimental findings, one can conclude that the cubic B-splines are a remarkable solution for the temporal alignment of plantar pressure image sequences. These findings also show that the temporal alignment can increase the consistency of the COP displacement on related acquired plantar pressure image sequences.     

Genome characteristics of facultatively symbiotic Frankia sp. strains reflect host range and host plant biogeography

Soil bacteria that also form mutualistic symbioses in plants encounter two major levels of selection. One occurs during adaptation to and survival in soil, and the other occurs in concert with host plant speciation and adaptation. Actinobacteria from the genus Frankia are facultative symbionts that form N₂-fixing root nodules on diverse and globally distributed angiosperms in the “actinorhizal” symbioses. Three closely related clades of Frankia sp. strains are recognized; members of each clade infect a subset of plants from among eight angiosperm families. We sequenced the genomes from three strains; their sizes varied from 5.43 Mbp for a narrow host range strain (Frankia sp. strain HFPCcI3) to 7.50 Mbp for a medium host range strain (Frankia alni strain ACN14a) to 9.04 Mbp for a broad host range strain (Frankia sp. strain EAN1pec.) This size divergence is the largest yet reported for such closely related soil bacteria (97.8%–98.9% identity of 16S rRNA genes). The extent of gene deletion, duplication, and acquisition is in concert with the biogeographic history of the symbioses and host plant speciation. Host plant isolation favored genome contraction, whereas host plant diversification favored genome expansion. The results support the idea that major genome expansions as well as reductions can occur in facultative symbiotic soil bacteria as they respond to new environments in the context of their symbioses.     

Computer-based sessions in radiological anatomy: one year’s experience in clinical anatomy

In the last curricular review (1995/96) radiological anatomy was introduced as an innovation in the program of the course of clinical anatomy of the Medical School. Since computer-based media are known to facilitate the understanding of the human body, computer technology was selected in the academic year of 1997/98 as an elective educational tool to teach radiological anatomy. CD-ROMs were introduced as additional instructional resources in 1997/98. This technology aimed to provide educational support to the program, namely, to the sessions of radiological anatomy in each section of the course head, neck, thorax, abdomen, pelvis and perineum. A questionnaire was designed to evaluate the opinion of the students enrolled in this course, focusing on the teaching sessions of radiological anatomy. Of 152 students, 135 (88.8%) returned the questionnaire. To describe the relationship between the value of this technology and several aspects of its organisation and adequacy, the Spearman rank correlation coefficient was used canonical correlation was used for the various practical sessions. The comments of students were very positive emphasising the quality of the media, organisation of the course, immediate feedback, degree of interactivity and simplicity of use they suggested a larger facility for the computers and acquisition of more programs and hardware. The positive evaluation of the use of the CD-ROMs in clinical anatomy allows us to foresee the formal integration of these instructional tools in the whole course, and not to restrict its use to specific units within the course.     

Correlation of noxious evoked c-fos expression in areas of the somatosensory system during chronic pain: involvement of spino-medullary and intra-medullary connections

Chronic pain induces functional alterations of the endogenous pain control system namely in the modulation of nociceptive transmission at the spinal cord. We used the c-fos expression as a tool to study correlated neuronal activation, induced by bending the inflamed paw of monoarthritic animals, between the spinal dorsal horn and medullary centers belonging to the endogenous pain control system, namely the lateralmost reticular formation of the ventrolateral medulla (VLMlat), the lateral reticular nucleus (LRt), the dorsal reticular nucleus (DRt), the nucleus tractus solitarius (Sol) and the rostroventromedial medulla (RVM). Awake monoarthritic rats were subjected to 4 min of paw bending followed by anaesthesia and perfusion either immediately or 2h later. The numbers of Fos immunoreactive neurons in the spinal dorsal horn and in the medulla oblongata were significantly correlated mainly immediately after stimulation: lamina I correlated with the VLMlat, LRt, Sol and RVM; lamina II correlated with the VLMlat, LRt and Sol; and laminae IV-V correlated with the VLMlat and LRt. Between medullary pain control centers significant correlations occurred immediately and 2h after bending at the VLMlat-Sol and LRt-Sol, at the VLMlat-LRt and VLMlat-RVM in animals perfused immediately, and at the VLMlat-DRt and LRt-RVM in animals perfused 2h later. These data demonstrate that the mobilization of a chronically inflamed paw triggers intense correlated neuronal activity in several areas of the somatosensory system, indicating functional relevant links in pain control.