The 2000 Ogura Lecture: Olfactory neural cells: An untapped diagnostic and therapeutic resource

Objective. This is an over-view of the cellular biology of upper nasal mucosal cells that have special characteristics that enable them to be used to diagnose and study congenital neurological diseases and to aid neural repair. Study Design: After mapping the distribution of neural cells in the upper nose, the authors' investigations moved to the use of olfactory neurones to diagnose neurological diseases of development, especially schizophrenia. Olfactory-ensheating glial cells (OEGs) from the cranial cavity promote axonal penetration of the central nervous system and aid spinal cord repair in rodents. The authors sought to isolate these cells from the more accessible upper nasal cavity in rats and in humans and prove they could likewise promote neural regeneration, making these cells suitable for human spinal repair investigations. Methods: The schizophrenia-diagnosis aspect of the study entailed the biopsy of the olfactory areas of 10 schizophrenic patients and 10 control subjects. The tissue samples were sliced and grown in culture medium. The ease of cell attachment to fibronectin (artificial epithelial basement membrane), as well as the mitotic and apoptotic indices, was studied in the presence and absence of dopamine in those cell cultures. The neural repair part of the study entailed a harvesting and insertion of first rat olfactory lamina propria rich in OEGs between cut ends of the spinal cords and then later the microinjection of an OEG-rich suspension into rat spinal cords previously transected by open laminectomy. Further studies were done in which OEG insertion was performed up to 1 month after rat cord transection and also in monkeys. Results: Schizophrenic patients' olfactory tissues do not easily attach to basement membrane compared with control subjects, adding evidence to the theory that cell wall anomalies are part of the schizophrenic lesion of neurones. Schizophrenic patient cell cultures had higher mitotic and apoptotic indices compared with control subjects. The addition of dopamine altered these indices enough to allow accurate differentiation of schizophrenics from control patients, leading to, possibly for the first time, an early objective diagnosis of schizophrenia and possible assessment of preventive strategies. OEGs from the nose were shown to be as effective as those from the olfactory bulb in promoting axonal growth across transected spinal cords even when added I month after injury in the rat. These otherwise paraplegic rats grew motor and proprioceptive and fine touch fibers with corresponding behavioral improvement. Conclusions. The tissues of the olfactory mucosa are readily available to the otolaryngologist. Being surface cells, they must regenerate (called neurogenesis). Biopsy of this area and amplification of cells in culture gives the scientist a window to the developing brain, including early diagnosis of schizophrenia. The Holy Grail of neurological disease is the cure of traumatic paraplegia and OEGs from the nose promote that repair. The otolaryngologist may become the necessary partner of the neurophysiologist and spinal surgeon to take the laboratory potential of paraplegic cure into the day-to-day realm of clinical reality.

Single-chain antibodies produced by phage display against the C-terminal 19 kDa region of merozoite surface protein-1of Plasinodium yoelii reduce parasite growth following challenge

Antibodies have the potential to be therapeutic reagents for malaria. Here we describe the production of a novel phage antibody display library against the C-terminal 19 kDa region of the Plasmodium yoelii YM merozoite surface protein-1 (MSP1(19)). In vivo studies against homologous lethal malaria challenge show an anti-parasite effect in a dose dependent manner, and analysis by plasmon resonance indicates binding to the antigen is comparable to the binding of a protective monoclonal antibody. The data support the lack of a need for any antibody Fc-related function and hold great significance for the development of a therapeutic reagent for malaria. (C) 2002 Elsevier Science Ltd. All rights reserved.

Identification of T cell epitopes on the 33-kDa fragment of Plasmodium yoelii merozoite surface protein 1 and their antibody-independent protective role in immunity to blood stage malarial

Merozoite surface protein 1 (MSP1) of malaria parasites undergoes proteolytic processing at least twice before invasion into a new RBC. The 42-kDa fragment, a product of primary processing, is cleaved by proteolytic enzymes giving rise to MSP1(33), which is shed from the merozoite surface, and MSP1(19), which is the only fragment carried into a new RBC. In this study, we have identified T cell epitopes on MSP1(33) of Plasmodium yoelii and have examined their function in immunity to blood stage malaria. Peptides 20 aa in length, spanning the length of MSP1(33) and overlapping each other by 10 aa, were analyzed for their ability to induce T cell proliferation in immunized BALB/c and C57BL/6 mice. Multiple epitopes were recognized by these two strains of mice. Effector functions of the dominant epitopes were then investigated. Peptides Cm15 and Cm21 were of particular interest as they were able to induce effector T cells capable of delaying growth of lethal P. yoelii YM following adoptive transfer into immuno-deficient mice without inducing detectable Ab responses. Homologs of these epitopes could be candidates for inclusion in a subunit vaccine.

Influence of ageing, heat shock treatment and in vivo total antioxidant status on gene-expression profile and protein synthesis in human peripheral lymphocytes

Ageing results in a progressive, intrinsic and generalised imbalance of the control of regulatory systems. A key manifestation of this complex biological process includes the attenuation of the universal stress response. Here we provide the first global assessment of the ageing process as it affects the heat shock response, utilising human peripheral lymphocytes and cDNA microarray analysis. The genomic approach employed in our preliminary study was supplemented with a proteomic approach. In addition, the current study correlates the in vivo total antioxidant status with the age-related differential gene expression as well as the translational kinetics of heat shock proteins (hsps). Most of the genes encoding stress response proteins on the 4224 element microarray used in this study were significantly elevated after heat shock treatment of lymphocytes obtained from both young and old individuals albeit to a greater extent in the young. Cell signaling and signal transduction genes as well as some oxidoreductases showed varied response. Results from translational kinetics of induction of major hsps, from 0 to 24 It recovery period were broadly consistent with the differential expression of HSC 70 and HSP 40 genes. Total antioxidant levels in plasma from old individuals were found to be significantly lower by comparison with young, in agreement with the widely acknowledged role of oxidant homeostasis in the ageing process. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

Cortex, cognition and the cell: New insights into the pyramidal neuron and prefrontal function

Arguably the most complex conical functions are seated in human cognition, the how and why of which have been debated for centuries by theologians, philosophers and scientists alike. In his best-selling book, An Astonishing Hypothesis: A Scientific Search for the Soul, Francis Crick refined the view that these qualities are determined solely by cortical cells and circuitry. Put simply, cognition is nothing more, or less, than a biological function. Accepting this to be the case, it should be possible to identify the mechanisms that subserve cognitive processing. Since the pioneering studies of Lorent de No and Hebb, and the more recent studies of Fuster, Miller and Goldman-Rakic, to mention but a few, much attention has been focused on the role of persistent neural activity in cognitive processes. Application of modern technologies and modelling techniques has led to new hypotheses about the mechanisms of persistent activity. Here I focus on how regional variations in the pyramidal cell phenotype may determine the complexity of cortical circuitry and, in turn, influence neural activity. Data obtained from thousands of individually injected pyramidal cells in sensory, motor, association and executive cortex reveal marked differences in the numbers of putative excitatory inputs received by these cells. Pyramidal cells in prefrontal cortex have, on average, up to 23 times more dendritic spines than those in the primary visual area. I propose that without these specializations in the structure of pyramidal cells, and the circuits they form, human cognitive processing would not have evolved to its present state. I also present data from both New World and Old World monkeys that show varying degrees of complexity in the pyramidal cell phenotype in their prefrontal cortices, suggesting that cortical circuitry and, thus, cognitive styles are evolving independently in different species.

Pyramidal cell heterogeneity in the visual cortex of the nocturnal new world owl monkey (aotus trivirgatus)

Recent studies have revealed marked variation in pyramidal cell structure in the visual cortex of macaque and marmoset monkeys. In particular, there is a systematic increase in the size of, and number of spines in, the arbours of pyramidal cells with progression through occipitotemporal (OT) visual areas. In the present study we extend the basis for comparison by investigating pyramidal cell structure in visual areas of the nocturnal owl monkey. As in the diurnal macaque and marmoset monkeys, pyramidal cells became progressively larger and more spinous with anterior progression through OT visual areas. These data suggest that: 1. the trend for more complex pyramidal cells with anterior progression through OT visual areas is a fundamental organizational principle in primate cortex; 2. areal specialization of the pyramidal cell phenotype provides an anatomical substrate for the reconstruction of the visual scene in OT areas; 3. evolutionary specialization of different aspects of visual processing may determine the extent of interareal variation in the pyramidal cell phenotype in different species; and 4. pyramidal cell structure is not necessarily related to brain size. Crown Copyright (C) 2003 Published by Elsevier Science Ltd on behalf of IBRO. All rights reserved.

The pyramidal neuron in occipital, temporal and prefrontal cortex of the owl monkey (Aotus trivirgatus): regional specialization in cell structure

Recent studies have revealed marked regional variation in pyramidal cell morphology in primate cortex. In particular, pyramidal cells in human and macaque prefrontal cortex (PFC) are considerably more spinous than those in other cortical regions. PFC pyramidal cells in the New World marmoset monkey, however, are less spinous than those in man and macaques. Taken together, these data suggest that the pyramidal cell has become more branched and more spinous during the evolution of PFC in only some primate lineages. This specialization may be of fundamental importance in determining the cognitive styles of the different species. However, these data are preliminary, with only one New World and two Old World species having been studied. Moreover, the marmoset data were obtained from different cases. In the present study we investigated PFC pyramidal cells in another New World monkey, the owl monkey, to extend the basis for comparison. As in the New World marmoset monkey, prefrontal pyramidal cells in owl monkeys have relatively few spines. These species differences appear to reflect variation in the extent to which PFC circuitry has become specialized during evolution. Highly complex pyramidal cells in PFC appear not to have been a feature of a common prosimian ancestor, but have evolved with the dramatic expansion of PFC in some anthropoid lineages.

Dendritic branching of pyramidal cells in the visual cortex of the nocturnal owl monkey: A fractal analysis

The branching structure of neurones is thought to influence patterns of connectivity and how inputs are integrated within the arbor. Recent studies have revealed a remarkable degree of variation in the branching structure of pyramidal cells in the cerebral cortex of diurnal primates, suggesting regional specialization in neuronal function. Such specialization in pyramidal cell structure may be important for various aspects of visual function, such as object recognition and color processing. To better understand the functional role of regional variation in the pyramidal cell phenotype in visual processing, we determined the complexity of the dendritic branching pattern of pyramidal cells in visual cortex of the nocturnal New World owl monkey. We used the fractal dilation method to quantify the branching structure of pyramidal cells in the primary visual area (V1), the second visual area (V2) and the caudal and rostral subdivisions of inferotemporal cortex (ITc and ITr, respectively), which are often associated with color processing. We found that, as in diurnal monkeys, there was a trend for cells of increasing fractal dimension with progression through these cortical areas. The increasing complexity paralleled a trend for increasing symmetry. That we found a similar trend in both diurnal and nocturnal monkeys suggests that it was a feature of a common anthropoid ancestor.

Efeitos da modulação do sistema endocanabinoide na interação social e extinção da memória aversiva em macacos-prego (Sapajus spp)

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Ciências Fisiológicas, Programa de Pós Graduação em Biologia Animal, 2016.

Yellow fever in Brazil: thoughts and hypotheses on the emergence in previously free areas

This article describes and discusses factors associated to the reemergence of yellow fever and its transmission dynamics in the states of São Paulo (Southeastern Brazil) and Rio Grande do Sul (Southern) during 2008 and 2009. The following factors have played a pivotal role for the reemergence of yellow fever in these areas: large susceptible human population; high prevalence of vectors and primary hosts (non-human primates); favorable climate conditions, especially increased rainfall; emergence of a new genetic lineage; and circulation of people and/or monkeys infected by virus. There is a need for an effective surveillance program to prevent the reemergence of yellow fever in other Brazilian states.

Coral snake venoms: mode of action and pathophysiology of experimental envenomation

Coral snakes, the New World Elapidae, are included in the genera Micniroides and Micrurus. The genus Mlcrurus comprises nearly all coral snake species and those which are responsible for human snake-bite accidents. The following generalizations concerning the effects induced by their venoms, and their venom-properties can be made. Coral snake venoms are neurotoxic, producing loss of muscle strenght and death by respiratory paralysis. Local edema and necrosis are not induced nor blood coagulation or hemorrhages. Proteolysis activity is absent or of very low grade. They display phospholipase A2 activity. Nephrotoxic effects are not evoked. The main toxins from elapid venoms are postsynaptic and presynaptic neurotoxins and cardiotoxins. Phospholipases A2 endowed with myonecrotic or cardiotoxin-like properties are important toxic components from some elapid venoms. The mode of action of Micrurus frontalis, M. lemniscatus, M. corallinus and M. fulvius venoms has been investigated in isolated muscle preparations and is here discussed. It is shown that while M. frontalis and M. lemniscatus venoms must contain only neurotoxins that act at the cholinergic end-plate receptor (postsynaptic neurotoxins), M. corallinus venom also inhibits evoked acetylcholine release by the motor nerve endings (presynaptic neurotoxin-like effect) and M. fulvius induces muscle fiber membrane depolarization (cardiotoxin-like effect). The effects produced by M. corallinus and M. fulvius venoms in vivo in dogs and M. frontalis venom in dogs and monkeys are also reported.

Neostigmine in the treatment of snake accidents caused by Micrurus frontalis: report of two cases

Antivenom in order to be effective in the treatment of coral snake accidents must be injected very soon after the bite owing to the rapid rate of absorption of the venom neurotoxins. As this is not always possible, other forms of treatment besides serotherapy must be employed to avoid asphyxia and death. Neostigmine and artificial respiration are used for this purpose. Neostigmine restores neuromuscular transmission if the venom-induced blockade results from a reversible interaction of its neurotoxins with the end-plate receptors. This is the mechanism of the neuromuscular blockade produced by the venom of M. frontalis snakes from centereastern and southern Brazil, and Argentine. Neostigmine is able, therefore, to antagonize the blockade, and has been shown to be very effective in the treatment of the experimental envenomation of dogs and monkeys. In the present communication, two cases of M. frontalis accidents treated with antivenom and neostigmine are reported. In both, neostigmine was successful in producing regression of the paralysis, confirming the effectiveness shown in the treatment of the poisoning induced in animals by M. frontalis venom.

A preliminary investigation on the gastrointestinal helminths of the Barbados green monkey, Cercopithecus aethiops sabaeus

Faecal samples were collected from fifty three freshly captured monkeys which were kept at the Barbados Primate Research Centre and Wildlife Reserve (BPRCWR). Examination of these samples for gastrointestinal helminths using the zinc sulphate floatation method revealed an overall infection rate of 88.7%.The parasites observed included Strongyloides (62.4%), Physaloptera (58.5%), Trichuris (52.8%), Hookworm (34.0%), Oesophagostomum (30.2%), Trichostrongylus (3.8%) and Ascaris (5.7%). No significant differences in overall prevalence were observed according to sex or age. Polyparasitism appeared to be common as it was observed in 92.5% of all monkeys examined. It is concluded that these monkeys could act as reservoirs of some of the parasites which can infect man.

Circulation of antibodies against yellow fever virus in a simian population in the area of Porto Primavera Hydroelectric Plant, São Paulo, Brazil

Yellow fever (YF) is an acute viral infectious disease transmitted by mosquitoes which occurs in two distinct epidemiological cycles: sylvatic and urban. In the sylvatic cycle, the virus is maintained by monkey's infection and transovarian transmission in vectors. Surveillance of non-human primates is required for the detection of viral circulation during epizootics, and for the identification of unaffected or transition areas. An ELISA (enzyme-linked immunosorbent assay) was standardized for estimation of the prevalence of IgG antibodies against yellow fever virus in monkey sera (Alouatta caraya) from the reservoir area of Porto Primavera Hydroelectric Plant, in the state of São Paulo, Brazil. A total of 570 monkey sera samples were tested and none was reactive to antibodies against yellow fever virus. The results corroborate the epidemiology of yellow fever in the area. Even though it is considered a transition area, there were no reports to date of epizootics or yellow fever outbreaks in humans. Also, entomological investigations did not detect the presence of vectors of this arbovirus infection. ELISA proved to be fast, sensitive, an adequate assay, and an instrument for active search in the epidemiological surveillance of yellow fever allowing the implementation of prevention actions, even before the occurrence of epizootics.

Isolation of yellow fever virus (YFV) from naturally infectied Haemagogus (Conopostegus) leucocelaenus (diptera, cukicudae) in São Paulo State, Brazil, 2009

After detecting the death of Howlers monkeys (genus Alouatta) and isolation of yellow fever virus (YFV) in Buri county, São Paulo, Brazil, an entomological research study in the field was started. A YFV strain was isolated from newborn Swiss mice and cultured cells of Aedes albopictus - C6/36, from a pool of six Haemagogus (Conopostegus) leucocelaenus (Hg. leucocelaenus) mosquitoes (Dyar & Shannon) collected at the study site. Virus RNA fragment was amplified by RT-PCR and sequenced. The MCC Tree generated showed that the isolated strain is related to the South American I genotype, in a monophyletic clade containing isolates from recent 2008-2010 epidemics and epizootics in Brazil. Statistical analysis commonly used were calculated to characterize the sample in relation to diversity and dominance and indicated a pattern of dominance of one or a few species. Hg. leucocelaenus was found infected in Rio Grande do Sul State as well. In São Paulo State, this is the first detection of YFV in Hg. leucocelaenus.