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J Anderson

Publications and source records attributed to J Anderson.

At least 127 records · Page 7Linked to original sources
PubMed2000

Contrast-detail characteristic evaluations of several display devices.

The contrast-detail characteristic of a display system is a powerful tool for evaluating displayed image quality. It takes into account the physical properties of the display, the psychophysical aspects of the observer, and the viewing conditions. It is a more sensitive measurement of the displayed image quality than a simple Society of Motion Picture and Television (SMPTE) pattern. Yet, it is relatively simple to measure and requires no special equipment or analysis tools. In this presentation, the results of the evaluation of several cathode ray tube (CRT) monitors and a digital projector will be presented. Contrast-detail characteristics of these display devices were measured under various gamma and display settings. The results show excellent intraobserver and interobserver variance (<1 step on the grayscale). Extraneous light, such as room lighting, affects the contrast threshold more severely at low background levels more than at high background. Gamma settings on graphics adapters affect the shapes of the contrast-detail curve for all display types. Gamma settings of approximately 2.0 result in a better contrast threshold for both high and low background brightness. The results show complex differences in contrast-detail characteristics for different display types. The digital projector display not only has significantly worse performance than CRT monitors, but also is affected more by extraneous light. High-brightness monitors with optimal monitor and graphics adapter settings have better performance than color or low-brightness monitors. However, under some settings, the performance of high-brightness monitors is not always better at all object sizes and background levels.

Computer Terminals↗
PubMed2000

Gene structure of human and mouse NKLAM, a gene associated with cellular cytotoxicity.

A novel gene involved in cytotoxicity, NKLAM [for "natural killer (NK) lytic-associated molecule"], has recently been identified in human NK cells. Its expression correlates with the cytolytic activity of both NK cells and cytotoxic T cells (CTLs); treatment of these cells with NKLAM-specific antisense oligonucleotides inhibits their cytotoxic function. NKLAM encodes a zinc finger protein that resides in NK cytolytic granules. Here, we identified a second human NKLAM transcript that differs from the original only at the 3' end, extending the open reading frame, and therefore encoding a significantly longer protein (731 residues compared with 587). The genomic structure of human NKLAM indicates that these two isoforms are products of alternative splicing. Both forms of NKLAM protein are expressed in NK cells, with the larger protein predominant. Human NKLAM cDNA was used to isolate mouse NKLAM from a C57BL/6 spleen cDNA library. There is a single NKLAM isoform in the mouse which shares over 89% nucleotide and 94% amino acid homology with the larger human form of NKLAM. The genomic organization of NKLAM is similar in both mouse and human. As with human NKLAM, mouse NKLAM mRNA is selectively expressed in CD8+ T cells NK cells, and activated peritoneal macrophages and further induced by cytokines that enhance the cytotoxic activity of these cells. These results indicate that human and mouse NKLAM are highly conserved both structurally and functionally, reinforcing the premise that this gene plays an important role in cellular cytotoxicity.

Amino Acid Sequence↗
PubMed2000

Site-specific invasion of the basal ganglia by Nocardia asteroides GUH-2.

Nocardia asteroides GUH-2 (GUH-2) invades the nigrostriatal region of the brain in mice [15]. Selective dopaminergic neuronal dropout in the substantia nigra results in parkinsonian changes characterized by movement disorders responsive to L-dopa [15]. This is the only reported example of an experimental bacterial model for parkinsonism. Following i.v. inoculation of GUH-2 into the non-human primate Macaca fasicularius, the nocardiae preferentially invaded and grew within the basal ganglia (substantia nigra, caudate, putamen, and globus pallidus) often without inducing apparent inflammation. Reduced, limited growth of nocardiae occurred in the white matter of the cerebral cortex, medulla, and hippocampus, whereas neither significant adherence to nor growth within the meninges was observed. Twenty-four hours after injection, nocardial cells were found within capillary endothelial cells, the basal lamina, neurons, astroglia and in axonal extensions. The bacteria, in endothelial cells, were surrounded by a unit membrane, but in the basal lamina they appeared to be free and not membrane bound. After the organisms passed into the brain parenchyma, the nocardiae once again became surrounded by membrane, often being encapsulated by numerous layers with the innermost layer tightly adherence to the bacterial surface. There was a propensity for nocardial growth within and along myelinated axons, either with or without disruption to the surrounding myelin sheath. There was electron microscopic evidence that the nocardiae induced a neurodegenerative response especially in the substantia nigra region. Thus, the early interactions of GUH-2 within the primate brain appeared to be similar to those reported in the mouse.

Animals↗
PubMed2000

A simple and accurate method for determination of microsatellite total allele content differences between DNA pools.

DNA pooling is a potential tool for the efficient analysis of the large numbers of samples and DNA markers that are necessary for genome-wide association studies. A simple accurate method for measuring total allele differences in comparisons between two pools containing large numbers of DNA samples is presented. This method compares relative peak height differences between electrophoretograms for each allele of a microsatellite. The method was evaluated by the analysis of 11 microsatellite markers and DNA pooled sample sizes of 50, 100, and 200 individual DNA samples from the same number of different subjects. Pools were created from previously individually genotyped subjects and constructed so that the pool comparisons would provide real total allele differences varying from 0% to 55%. Calculated pool differences were then compared with the real total allele differences determined by individual genotyping results. Together over 200 comparisons demonstrated a correlation coefficient of 0.96, which compared favorably with other previous methods of analysis. This method could provide a rapid screen for total allele differences of greater than 10%, a threshold that should be applicable to detecting low relative risk genes in common diseases. Therefore, these studies suggest that DNA pooling could be a useful tool in association studies for the determination of candidate regions for a range of complex genetic diseases.

Alleles↗
PubMed2000

Treatment of human immunodeficiency virus during pregnancy: the shift from an exclusive focus on fetal protection to a more balanced approach.

A review is presented of policy and treatment guidelines for human immunodeficiency virus infection in pregnancy. Interventions that serve the best interests of pregnant women and their fetuses are suggested. Reproductive studies with animals should be done routinely, and more research with pregnant women should be conducted. Women and their health care providers need to shift away from the "therapeutic nihilism" paradigm. All clinical decisions must be made cautiously and thoughtfully, with the understanding that the health needs of the pregnant woman are usually whatever is in the best interest of the developing fetus.

Animals↗
PubMed2000

A new technique for securing a foley catheter.

We describe a new technique to secure a urethral catheter using a horizontal drain tube stabilizer. This device is reliable, inexpensive, and more comfortable for patients than either adhesive tape or leg straps.

Humans↗
PubMed2000

A poly(ortho ester) designed for combined ocular delivery of dexamethasone sodium phosphate and 5-fluorouracil: subconjunctival tolerance and in vitro release.

A viscous hydrophobic poly(ortho ester) (POE) has been developed as a biocompatible, biodegradable sustained release system for selected cases of glaucoma filtering surgery. Dexamethasone and 5-fluorouracil (5-FU) are frequently administered together post-operatively, for their anti-fibroblastic and anti-inflammatory properties, respectively. A combined sustained release of both drugs could be advantageously used. Drug release kinetics were studied using specially designed thermostated cells. Subconjunctival tolerance was evaluated on New Zealand albino rabbits by clinical evaluation. Due to its basicity, the addition of dexamethasone sodium phosphate (DEX-P) stabilized the polymer and prolonged 5-FU in vitro release from 2 to 4 days. Both therapeutic agents were released concomitantly, according to a linear profile. The presence of 5-FU only slightly affected the overall subconjunctival tolerance of POE in rabbits, whereas the addition of DEX-P markedly improved POE tolerance by reducing the hyperemia of the conjunctiva to a minimal grade.

Animals↗
PubMed2000

Uncharged tRNA activates GCN2 by displacing the protein kinase moiety from a bipartite tRNA-binding domain.

Protein kinase GCN2 regulates translation in amino acid-starved cells by phosphorylating elF2. GCN2 contains a regulatory domain related to histidyl-tRNA synthetase (HisRS) postulated to bind multiple deacylated tRNAs as a general sensor of starvation. In accordance with this model, GCN2 bound several deacylated tRNAs with similar affinities, and aminoacylation of tRNAphe weakened its interaction with GCN2. Unexpectedly, the C-terminal ribosome binding segment of GCN2 (C-term) was required in addition to the HisRS domain for strong tRNA binding. A combined HisRS+ C-term segment bound to the isolated protein kinase (PK) domain in vitro, and tRNA impeded this interaction. An activating mutation (GCN2c-E803V) that weakens PK-C-term association greatly enhanced tRNA binding by GCN2. These results provide strong evidence that tRNA stimulates the GCN2 kinase moiety by preventing an inhibitory interaction with the bipartite tRNA binding domain.

Binding Sites↗
PubMed2000

Knowledge, skills, and behavior improvements on peer educators and low-income Hispanic participants after a stage of change-based bilingual nutrition education program.

A nutrition education program, entitled La Cocina Saludable, was designed according to the Stage of Change Model and implemented in ten southern Colorado counties. The objectives were to improve the nutrition related knowledge, skills, and behaviors that lead to healthy lifestyles in a low-income Hispanic population. The content of the program included nutrition information designed to help mothers of preschool children provide for their children's nutritional needs. Previous studies suggest that low-income Hispanics often demonstrate low intakes of vitamins A and C, calcium, iron, and protein, and high rates of diabetes, obesity, and infections. Additionally, this population presents many obstacles for nutrition educators including limited resources, child care, transportation, time, language, culture, literacy, health beliefs, and, in some cases, the transient nature of the population. The program attempted to overcome these barriers by incorporating a flexible program format carried out by abuela (Hispanic grandmother) educators using the processes described in the Stage of Change Model. The program was evaluated using a knowledge, skills and behavior pre-test, post-test, and six-month follow-up survey on both the abuela educators as well as the actual class participants. Results of the peer education training sessions suggest that this type of training program can be effective in increasing the knowledge, skills, and behavior of peer educators as well as reduce need for retraining for educators who continuously teach classes. Additionally, the results suggest that this type of program can be effective in changing selected nutrition related knowledge, skills, and behaviors leading to healthy lifestyles for low-income Hispanic mothers of preschool children.

Adult↗
PubMed2000

Diagnosis of rinderpest in Tanzania by a rapid chromatographic strip-test.

A simple chromatographic strip-test based on Clearview technology, is under development as a pen-side test for the detection of rinderpest antigen in eye swabs taken from cattle in the field. An outbreak of rinderpest occurred in the northern zone of Tanzania from late February to June 1997. The affected cattle exhibited very mild clinical signs, which made clinical diagnosis difficult. One hundred and seven eye swabs were collected from cattle suspected of infection with rinderpest. These were tested in the field using a prototype of the pen-side test and 13 (12.15%) of the samples were found to be positive for the presence of rinderpest antigen. These were confirmed by ICE. The positive cases were predominantly found in the Ngorongoro district. This demonstrates the usefulness of such a simple, rapid pen-side diagnostic assay, particularly when clinically 'mild' strains of rinderpest are present.

Animals↗
PubMed2000

Stimulus dependence of two-state fluctuations of membrane potential in cat visual cortex.

Membrane potentials of cortical neurons fluctuate between a hyperpolarized ('down') state and a depolarized ('up') state which may be separated by up to 30 mV, reflecting rapid but infrequent transitions between two patterns of synaptic input. Here we show that such fluctuations may contribute to representation of visual stimuli by cortical cells. In complex cells of anesthetized cats, where such fluctuations are most prominent, prolonged visual stimulation increased the probability of the up state. This probability increase was related to stimulus strength: its dependence on stimulus orientation and contrast matched each cell's averaged membrane potential. Thus large fluctuations in membrane potential are not simply noise on which visual responses are superimposed, but may provide a substrate for encoding sensory information.

Anesthesia↗
PubMed2000

Numerical analysis of blood flow in the clearance regions of a continuous flow artificial heart pump.

The CFVAD3 is the third prototype of a continuous flow ventricular assist device being developed for implantation in humans. The pump consists of a fully shrouded 4-blade impeller supported by magnetic bearings. On either side of this suspended rotating impeller is a small clearance region through which the blood flows. The spacing and geometry of these clearance regions are very important to the successful operation of this blood pump. Computational fluid dynamics (CFD) solutions for this flow were obtained using TascFlow, a software package available from AEA Technology, U.K. Flow in these clearance regions was studied parametrically by varying the size of the clearance, the blood flow rate into the pump, and the rotational speed of the pump. The numerical solutions yield the direction and magnitude of the flow and the dynamic pressure. Experimentally measured pump flow rates are compared to the numerical study. The results of the study provide guidance for improving pump efficiency. It is determined that current clearances can be significantly reduced to improve pump efficiency without negative impacts.

Computer Simulation↗
PubMed2000

Hepatic cirrhosis and portal hypertension in neuroblastoma.

Hepatic portal hypertension is an unusual complication of cancer therapy. The authors report 2 children under the age of 18 months with disseminated neuroblastoma who developed cavernous transformation of the portal vein during chemotherapy. While the older child remains well, the second patient succumbed from overwhelming variceal hemorrhage as a result of this condition. Full recovery of hepatic function is not invariable following the regression of extensive liver infiltration by neuroblastoma and consideration should be given to follow-up Doppler ultrasound imaging of the hepatic portal system in affected infants.

Female↗
PubMed2000

Overwintering and establishment of Aedes albopictus (Diptera: Culicidae) in an urban La Crosse virus enzootic site in Illinois.

In 1997, Aedes albopictus (Skuse) was discovered in Peoria, IL, a known focus of La Crosse (LAC) virus transmission. This accidental introduction provided an opportunity to determine whether Ae. albopictus would reemerge in the spring or summer and, if successful overwintering occurred, to follow changes in the geographic range of Ae. albopictus, and to compare its distribution to that of the local treehole mosquito and LAC vector Aedes triseriatus (Say). In 1998, 25 oviposition traps were placed in and around the area of the initial finding of Ae. albopictus, with adult collections by aspirators and larval collections from water-holding containers used to identify areas of additional activity. Ae. albopictus successfully survived the mild 1997-1998 El Niño winter, and expanded its range during 1998. By September 1998, Ae. albopictus oviposited in all 25 traps, including traps near and in wooded sites. Intensity of oviposition activity (number of eggs per positive trap) ranged from 20-40, lower than the range for Ae. triseriatus, which was as high as 175 eggs per infested trap in mid-August. Prevalence of Ae. albopictus increased through September, where as the prevalence of Ae. triseriatus declined starting in mid-July. Although direct competition between the two mosquito species cannot be inferred based on this surveillance effort, a gradual range expansion was observed, and Ae. albopictus eggs were collected in traps where initially only Ae. triseriatus oviposition activity was detected.

Aedes↗
PubMed2000

Development of a genetically marked recombinant rinderpest vaccine expressing green fluorescent protein.

In order to effectively control and eliminate rinderpest, a method is required to allow serological differentiation between animals that have been vaccinated and those which have recovered from natural infection. One way of doing this would be to engineer the normal vaccine to produce a genetically marked rinderpest virus (RPV) vaccine. We constructed two modified cDNA clones of the RPV RBOK vaccine strain with the coding sequence of the green fluorescent protein (GFP) gene inserted as a potential genetic marker. RPVINS-GFP virus was designed to produce independent and high level expression of GFP inside infected cells, whilst the GFP expressed by RPVSIG-GFP virus was designed to be efficiently secreted. Infectious recombinant virus was rescued in cell culture from both constructs. The effectiveness of these viruses in stimulating protective immunity and antibody responses to the marker protein was tested by vaccination of cattle and goats. All of the vaccinated animals were completely protected when challenged with virulent virus: RPV in cattle or peste-des-petits ruminants virus in the goats. ELISA showed that all of the animals produced good levels of anti-RPV antibodies. Three of the four cattle and the two goats vaccinated with RPVSIG-GFP produced detectable levels of anti-GFP antibodies. In contrast, no anti-GFP antibodies were produced in the four cattle and two goats vaccinated with RPVINS-GFP. Therefore, secretion of the GFP marker protein was absolutely required to elicit an effective humoral antibody response to the marker protein.

Animals↗
PubMed2000

Development, characterization, and diagnostic applications of monoclonal antibodies against bovine rotavirus.

Hybridomas secreting monoclonal antibodies (MAbs) against the Nebraska calf diarrhea strain of bovine rotavirus (BRV) were characterized. Indirect fluorescent-antibody assay, immunodot assay, and immunoprecipitation were used to select hybridomas that produced anti-BRV MAbs. Seven of the MAbs were shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot assay to be reactive with the BRV outer capsid protein, VP7, which has a molecular mass of 37.5 kDa. None of the seven MAbs were reactive with canine rotavirus, bovine coronavirus, or uninfected Madin-Darby bovine kidney cells. Two clones, 8B4 (immunoglobulin G2a [IgG2a]) and 2B11 (IgG1), were found suitable for use in an antigen capture enzyme-linked immunosorbent assay for detecting BRV in bovine fecal samples. Both were subtype A specific (G6 subtype) but did not react with all isolates of BRV group A.

Animals↗
PubMed2000

Zinc finger structures in the human immunodeficiency virus type 1 nucleocapsid protein facilitate efficient minus- and plus-strand transfer.

The nucleocapsid protein (NC) of human immunodeficiency virus type 1 (HIV-1) has two zinc fingers, each containing the invariant metal ion binding residues CCHC. Recent reports indicate that mutations in the CCHC motifs are deleterious for reverse transcription in vivo. To identify reverse transcriptase (RT) reactions affected by such changes, we have probed zinc finger functions in NC-dependent RT-catalyzed HIV-1 minus- and plus-strand transfer model systems. Our approach was to examine the activities of wild-type NC and a mutant in which all six cysteine residues were replaced by serine (SSHS NC); this mutation severely disrupts zinc coordination. We find that the zinc fingers contribute to the role of NC in complete tRNA primer removal from minus-strand DNA during plus-strand transfer. Annealing of the primer binding site sequences in plus-strand strong-stop DNA [(+) SSDNA] to its complement in minus-strand acceptor DNA is not dependent on NC zinc fingers. In contrast, the rate of annealing of the complementary R regions in (-) SSDNA and 3' viral RNA during minus-strand transfer is approximately eightfold lower when SSHS NC is used in place of wild-type NC. Moreover, unlike wild-type NC, SSHS NC has only a small stimulatory effect on minus-strand transfer and is essentially unable to block TAR-induced self-priming from (-) SSDNA. Our results strongly suggest that NC zinc finger structures are needed to unfold highly structured RNA and DNA strand transfer intermediates. Thus, it appears that in these cases, zinc finger interactions are important components of NC nucleic acid chaperone activity.

Genome, Viral↗