Proceedings of the 23rd Annual Symposium on Nonhuman Primate Models for AIDS. September 21-24, 2005. Portland, Oregon, USA.
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
AIM: To evaluate the safety of the long term vas occlusion with styrene maleic anhydride (SMA) and its non-invasive reversal at the level of accessory reproductive glands ARGs in langurs. METHODS: The morphology of seminal vesicle and ventral prostate was evaluated by light as well as transmission electron microscopy. Serum clinical chemistry and urine albumin were evaluated in an autoanalyzer using reagent kits. Fructose, acid phosphatase and zinc in the seminal plasma were evaluated spectrophotometrically according to the WHO manual. Serum testosterone, prostate specific antigen and sperm antibodies were evaluated by enzyme-linked immunosorbent assays (ELISA) using reagent kits and hematology was estimated according to standard procedures. RESULTS: The morphological features and secretory activity of the seminal vesicle and prostate were normal as evidenced by the presence of well-developed mitochondria, rough endoplasmic reticulum, Golgi bodies, secretory granules and normal nuclear characteristics throughout the course of investigation. Serum testosterone and prostate specific antigen remained unaltered and serum antisperm antibodies level presented negative titres. Urine albumin was nil. Total red blood corpuscles (RBC), white blood corpuscles (WBC), hemoglobin (Hb) and red cell indices, serum protein, glucose, cholesterol, creatinine, creatine kinase (CK), serum glutamate oxalate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), lactate dehydrogenase (LDH), bilirubin, urea, triglycerides and high-density lipoprotein (HDL) did not show appreciable changes following vas occlusion and after its non-invasive reversal. Although fructose, acid phosphatase (ACP) and zinc in the seminal plasma showed a significant reduction following vas occlusion, it could not be related to the morphology of seminal vesicle and prostate. CONCLUSION: SMA vas occlusion and its non-invasive reversal do not damage the accessory reproductive organs.
Explore the source record for details and available documents.
Infection of macaque monkeys with simian immunodeficiency virus (SIV) has been established as an excellent animal model system for studying the pathogenesis of an HIV-like virus and for evaluating newly developed antiretroviral drugs and vaccines. Based on their genetic, antigenic, and biologic properties, the simian immunodeficiency viruses are the closest known relatives of the human AIDS viruses, and experimental infection of macaque monkeys results in a disease that is remarkably similar to human AIDS. Infected macaques show diarrhea, weight loss, hematologic abnormalities including lymphopenia and thrombocytopenia, lymphadenopathy/lymphoid hyperplasia that progresses to lymphoid depletion, immunosuppression with marked reduction in CD4+ cells and in the CD4+/CD8+ cell ratio, and opportunistic infections. A majority of such macaques die from an AIDS-like disease within one to three years of infection. An acutely lethal variant of SIV has been identified that results in death in susceptible macaques within 7-12 days of infection. Preliminary prophylactic treatment trials with AZT in macaque monkeys exposed to the acutely lethal SIV variant indicate that some protection is provided when AZT treatment is initiated within 24 hours of virus exposure. Other studies with the more chronic SIV infection model, however, failed to show any prophylactic efficacy of CS-87, AZT, D4T, or FDT.
Explore the source record for details and available documents.
The tertiary structure of erythropoietin (EPO) remains to be elucidated by X-ray crystallography. Although the amino acid sequence of EPO is known, the specific features that confer its biological activity are not well understood. In order to study the structure-function relationships of EPO by in vitro mutagenesis, we have used the vector pGEX-2T to express human and murine EPO fused to the carboxyl terminus of glutathione S-transferase (GST) in E. coli. The fusion proteins were the predicted size (46 kDa) by SDS-PAGE. GST-huEPO eluted from glutathione-agarose using reduced glutathione (GSH) was tested by radioimmunoassay and in a mouse spleen cell assay (MSCA). Dose-response curves parallel to recombinant human EPO (rHuEPO) were obtained in both assays. The ratio of immuno- to bioactivity was 4.7:1. Thus the presence of the 26 kDa GST protein at the end terminus of EPO does not abrogate biological activity. GST-mEPO also gave dose-response curves parallel to rHuEPO in the MSCA but not in the RIA. The wild-type murine and three mutant GST-EPO fusion proteins (166 Des-Arg, Glu 159-->Val, and Arg 163-->Glu) were tested in the MSCA and assayed for GST activity. The ratio of bioactivity to enzyme activity for the Arg 163-->Glu mutant was approximately one third of the value obtained for each of the other fusion proteins, indicating that arginine at 163 is functionally important for EPO activity. The availability of these human and murine gene constructs in pGEX should facilitate site-directed mutagenesis and permit detailed studies of the structure-function relationships for the two erythropoietins.
Explore the source record for details and available documents.
We have studied the properties of neurones in the lateral geniculate nucleus (l.g.n.) of Old World monkeys, both in mature animals and throughout post-natal development. Cells were classified as X (linear) or Y (non-linear) on the basis of their responses to contrast-reversing achromatic gratings ('null position test'). In older animals virtually all parvocellular neurones and the majority of magnocellular units were X cells; only about 15% of magnocellular neurones displayed highly non-linear spatial summation, with no 'null position', typical of Y cells. X cells could not reliably be distinguished from Y cells, nor magnocellular from parvocellular, on the basis of their temporal patterns of discharge. Some Y cells responded transiently to contrast reversal of a grating far from the receptive field but X cells showed little or no such 'shift effect'. The spatial resolution of mature l.g.n. cells varied with the eccentricity of their receptive fields such that the best of them, at each point in the visual field, resolved drifting achromatic gratings about as well as a human observer. X cells in parvocellular and magnocellular layers had similar 'acuities', even in the central foveal representation, but Y cells generally had poorer resolution. Receptive fields in the temporal retina tended to have lower resolution than those at comparable eccentricities in the nasal retina. Even on the day of birth all cells we studied responded to visual stimulation and virtually all could be classified as X or Y. The laminar distribution of cell types and the general morphological appearance of the nucleus seemed very similar to those in the adult, but neurones in very young animals had low spontaneous activity, sluggish responses, and latencies to visual stimulation longer than any we saw in the adult. Until 3 weeks of age or so, many neurones suffered cumulative 'fatigue' when visually stimulated over several minutes. Visual latency was essentially mature by about 10 weeks. In the l.g.n. of the neonatal monkey there was little variation in neuronal 'acuity' with eccentricity: even in the foveal area the best cells could resolve only about 5 cycles/deg. Over the first year or more of life there is a gradual increase in responsiveness and about a 7-fold improvement in spatial resolution for foveal l.g.n. cells, correlating roughly with the behavioural maturation of visual acuity.
The anatomic consequences of acoustic overstimulation are explored in this presentation, and attention is directed toward issues where improvements in technology and empirical observation are needed before further advances in our understanding can be achieved. Gains have been made in the last decade in appreciating sound-induced cochlear injury, but there is now a need to evaluate not only cochlear pathology but also the functional state of the surviving structures. There is a wealth of information about the susceptibility of inner or outer hair cells to acoustic injury; however, the etiology of this injury is not yet fully understood. In addition, current ideas concerning the effects of noise on hair-cell stereocilia, hair-cell synapses, the cochlear vascular supply, and the central auditory pathways are in a state of flux and are either undergoing revision or emerging. Other issues, such as the basis of temporary or permanent threshold shift at the cellular level, and the individual differences in susceptibility to injury are in need of a fresh approach. It would seem that the time is now ripe to review our knowledge, recognize its gaps, and develop testable hypotheses concerning the mechanisms of acoustic injury to the ear.
Changes in auditory sensitivity as a function of signal duration were studied in two species of Old World monkeys. Testing was conducted under free-field conditions with pure tones 250, 800, 1600, and 4000 Hz in frequency. Test stimuli ranged in duration from 35-2000 ms. The results showed that the temporal integration functions for the blue monkeys were similar to those reported for rhesus monkeys [T. D. Clack, J. Acoust. Soc. Am. 40, 1140-1146 (1966)], but differed significantly from those for mangabey monkeys and human subjects tested in the same apparatus, by the same procedure. Integration functions for humans and mangabeys did not differ. It was concluded that some taxonomic groups of primates exhibit temporal integration times that are much longer than those characteristic of humans, while others do not, and that interspecific differences in temporal integration are not readily related to species differences in their vocal repertoires.
This study evaluated frequency discrimination ability in 11 monkeys over an extended period of time using a repeating-standard procedure and the method of constant stimuli. The intersubject variability of the difference limens for frequency (delta F) was large, as reported by other investigators, but similar in magnitude to the variability of the difference limens for intensity (delta I) from three of the same subjects in an intensity discrimination experiment. Continued training generally resulted in a rapid decrease in delta F's, followed by a longer-term, slower decrease. For one subject delta F's slowly decreased throughout a 190-week time period. This long-term training effect was specific to frequency discrimination; a similar effect was not observed for the same subject tested in an intensity discrimination experiment. Finally, delta F's from the well-trained monkeys of this study were larger than monkey delta F's from this laboratory reported in an earlier study, and than human delta F's. An anatomical explanation for the human/monkey delta F magnitude difference is explored.
It has been suggested that the human immunodeficiency virus (HIV), and thus the acquired immunodeficiency syndrome (AIDS) it causes, was inadvertently introduced to humans by the use of an oral polio vaccine (OPV) during a vaccination campaign launched by the Wistar Institute, Philadelphia, PA, USA, in the Belgian Congo in 1958 and 1959. The "OPV/AIDS hypothesis" suggests that the OPV used in this campaign was produced in chimpanzee kidney epithelial cell cultures rather than in monkey kidney cell cultures, as stated by H. Koprowski and co-workers, who produced the OPV. If chimpanzee cells were indeed used, this would lend support to the OPV/AIDS hypothesis, since chimpanzees harbor a simian immunodeficiency virus, widely accepted to be the origin of HIV-1. We analyzed several early OPV pools and found no evidence for the presence of chimpanzee DNA; by contrast, monkey DNA is present.
Nonhuman primates represent the most relevant model organisms to understand the biology of Homo sapiens. The recent divergence and associated overall sequence conservation between individual members of this taxon have nonetheless largely precluded the use of primates in comparative sequence studies. We used sequence comparisons of an extensive set of Old World and New World monkeys and hominoids to identify functional regions in the human genome. Analysis of these data enabled the discovery of primate-specific gene regulatory elements and the demarcation of the exons of multiple genes. Much of the information content of the comprehensive primate sequence comparisons could be captured with a small subset of phylogenetically close primates. These results demonstrate the utility of intraprimate sequence comparisons to discover common mammalian as well as primate-specific functional elements in the human genome, which are unattainable through the evaluation of more evolutionarily distant species.
Explore the source record for details and available documents.
Forty-two chromosomes were counted from expanded cultured cells of four Celebes apes, Cynopithecus niger. Mitotic cells from three Indian langurs, Presbytis entellus, contained 44 chromosomes. These counts support cytogenetically the taxonomical classification of these animals according to Simpson.
Explore the source record for details and available documents.
It has been proposed that modern humans descended from a single woman, the "mitochondrial Eve" who lived in Africa 100,000 to 200,000 years ago. The human immune system DRB1 genes are extremely polymorphic, with gene lineages that coalesce into an ancestor who lived around 60 million years ago, a time before the divergence of the apes from the Old World monkeys. The theory of gene coalescence suggests that, throughout the last 60 million years, human ancestral populations had an effective size of 100,000 individuals or greater. Molecular evolution data favor the African origin of modern humans, but the weight of the evidence is against a population bottleneck before their emergence. The mitochondrial Eve hypothesis emanates from a confusion between gene genealogies and individual genealogies.
Explore the source record for details and available documents.