Time-specific intraocular pressure curves in Rhesus macaques (Macaca mulatta) with laser-induced ocular hypertension.

Objective: To detect and categorize time-specific variations in daytime intraocular pressure (IOP) found in Rhesus monkeys with laser-induced ocular hypertension.

Procedures: Ten male monkeys with argon laser-induced ocular hypertension in one eye were anesthetized with ketamine hydrochloride, and the IOP measured in both eyes at 7 a.m.

Closterovirus bipolar virion: evidence for initiation of assembly by minor coat protein and its restriction to the genomic RNA 5' region.

The long flexuous virions of the Closteroviridae have a unique bipolar architecture incorporating two coat proteins, with most of the helical nucleocapsid encapsidated by the major coat protein (CP) and a small portion of one end encapsidated by the minor coat protein (CPm). It is not known whether CPm encapsidates the genomic RNA and, if so, which end and what effects transition between the two coat proteins. Two other virus-encoded proteins, an HSP70 homolog (HSP70h) and an approximately 61-kDa protein, are required to augment virion assembly.

The conserved structures of the 5' nontranslated region of Citrus tristeza virus are involved in replication and virion assembly.

The genomic RNA of different isolates of Citrus tristeza virus (CTV) reveals an unusual pattern of sequence diversity: the 3' halves are highly conserved (homology >90%), while the 5' halves show much more dissimilarity, with the 5' nontranslated region (NTR) containing the highest diversity (homology as low as 42%). Yet, positive-sense sequences of the 5' NTR were predicted to fold into nearly identical structures consisting of two stem-loops (SL1 and SL2) separated by a short spacer region. The predicted most stable secondary structures of the negative-sense sequences were more variable.

Frameshift mutations in infectious cDNA clones of Citrus tristeza virus: a strategy to minimize the toxicity of viral sequences to Escherichia coli.

The advent of reverse genetics revolutionized the study of positive-stranded RNA viruses that were amenable for cloning as cDNAs into high-copy-number plasmids of Escherichia coli. However, some viruses are inherently refractory to cloning in high-copy-number plasmids due to toxicity of viral sequences to E. coli.

Effects of modification of the transcription initiation site context on citrus tristeza virus subgenomic RNA synthesis.

Citrus tristeza virus (CTV), a member of the Closteroviridae, has a positive-sense RNA genome of about 20 kb organized into 12 open reading frames (ORFs). The last 10 ORFs are expressed through 3'-coterminal subgenomic RNAs (sgRNAs) regulated in both amounts and timing. Additionally, relatively large amounts of complementary sgRNAs are produced.

Long-term effect of retinal ganglion cell axotomy on the histomorphometry of other cells in the porcine retina.

Purpose: To determine the effect of retinal ganglion cell axotomy on the thickness of inner plexiform, inner nuclear, and outer plexiform layers, as well as the densities of short- and middle-to-long-wavelength cones, in the porcine retina.

Methods: Unilateral retinal ganglion cell axotomy was performed in seven domestic pigs by either surgical optic nerve section or peripapillary argon laser photocoagulation. Damage to the retinal vasculature was ruled out with fluorescein angiography.

Defective RNAs of Citrus tristeza virus analogous to Crinivirus genomic RNAs.

The family Closteroviridae includes the genera Closterovirus and Ampelovirus with monopartite genomes and the genus Crinivirus with bipartite genomes. Plants infected with the Closterovirus, Citrus tristeza virus (CTV), often contain one or more populations of defective RNAs (dRNAs). Although most dRNAs are comparatively small (2-5 kb) consisting of the genomic RNA termini with large internal deletions, we recently characterized large dRNAs of approximately 12 kb that retained the open reading frames (ORFs) 1a plus 1b.

Corneal thickness and endothelial cell density measured by non-contact specular microscopy and pachymetry in Rhesus macaques (Macaca mulatta) with laser-induced ocular hypertension.

Purpose: Sustained increase in intraocular pressure (IOP) in humans results in a loss of corneal endothelial cells and an increase of corneal thickness. The effects of chronically elevated IOP on the corneal endothelium of monkeys with laser-induced ocular hypertension, a commonly used animal model of human glaucoma have not been documented. This study examined the central corneal thickness (CCT), the corneal endothelial cell density (ECD), and the corneal endothelial cell size (ACS) in Rhesus monkeys with experimental ocular hypertension.

Passive attenuation of cortical pattern evoked potentials with increasing body weight in young male rhesus macaques.

The purpose of our study was to determine changes in amplitudes and implicit times of retinal and cortical pattern evoked potentials with increasing body weight in young, growing rhesus macaques (Macaca mulatta). Retinal and cortical pattern evoked potentials were recorded from 29 male rhesus macaques between 3 and 7 years of age. Thirteen animals were reexamined after 11 months.

Flash electroretinography in standing horses using the DTL microfiber electrode.

Purpose: The goal of our study was the evaluation of a practical method for the recording of flash electroretinograms (ERGs) in sedated, standing horses with the DTL microfiber electrode.

Methods: The horses were sedated intravenously with detomidine hydrochloride (0.015 mg/kg).

Transcription strategy in a Closterovirus: a novel 5'-proximal controller element of Citrus Tristeza Virus produces 5'- and 3'-terminal subgenomic RNAs and differs from 3' open reading frame controller elements.

Citrus tristeza virus (CTV) produces more than thirty 3'- or 5'-terminal subgenomic RNAs (sgRNAs) that accumulate to various extents during replication in protoplasts and plants. Among the most unusual species are two abundant populations of small 5'-terminal sgRNAs of approximately 800 nucleotides (nt) termed low-molecular-weight tristeza (LMT1 and LMT2) RNAs. Remarkably, CTV replicons with all 10 3' genes deleted produce only the larger LMT1 RNAs.

Mutational analysis of the replication signals in the 3'-nontranslated region of citrus tristeza virus.

Citrus tristeza virus (CTV), a member of the Closteroviridae, has a 19.3-kb messenger-sense RNA genome consisting of 12 open reading frames with nontranslated regions (NTR) at the 5' and 3' termini. The 273 nucleotide (nt) 3'-NTR is highly conserved ( approximately 95%) among the sequenced CTV isolates in contrast to the highly diverse 5'-NTR sequences.

Observer study involving laser-digitized versus CCD-digitized images.

We compared laser- and CCD-digitized images for perceived image quality differences in a radiologist-observer study. Films of 50 two- and three-view studies (ankles, chests, c-spines, shoulders) were digitized on calibrated laser (Kodak Lumisys 75) and CCD (VIDAR SIERRA Plus) digitizers. Six radiologists independently compared digitized images on twin high-resolution monochrome monitors.

Technical issues in electrodiagnostic recording.

Electroretinogram (ERG) and visual-evoked potentials (VEPs) are used in veterinary ophthalmology to assess the functional integrity of the retina and the central visual pathway. The interpretation of altered electrophysiologic potentials in diseases can be of great diagnostic value, although it is important to be aware of technical factors and the limitations of these techniques which may result in over-interpretation and misinterpretation of the recordings, such that they are similar to those found in disease-related electrophysiologic changes. The recorded potentials represent the differences in voltage between the active and reference electrodes.

The p23 protein of citrus tristeza virus controls asymmetrical RNA accumulation.

Citrus tristeza virus (CTV), a member of the Closteroviridae, has a 19.3-kb positive-stranded RNA genome that is organized into 12 open reading frames (ORFs) with the 10 3' genes expressed via a nested set of nine or ten 3'-coterminal subgenomic mRNAs (sgRNAs). Relatively large amounts of negative-stranded RNAs complementary to both genomic and sgRNAs accumulate in infected cells.

A physical origin for functional domain structure in nucleic acids as evidenced by cross-linking entropy: II.

In Part I, cross-linking entropy (CLE) was proposed as a mechanism that limits the size of functional domains of RNA. To test this hypothesis, the theory is developed into an RNA secondary structure prediction filter which is applied to nearest-neighbor secondary structure (NNSS) algorithms that utilize a free energy (FE) minimization strategy. (The NNSS strategies are also referred to as the dynamic programming algorithm in the literature.

A physical origin for functional domain structure in nucleic acids as evidenced by cross-linking entropy: I.

A global strategy for estimating the entropy of long sequences of RNA is proposed to help improve the predictive capacity of RNA secondary structure dynamic programming algorithm (DPA) free energy (FE) minimization methods. These DPA strategies only consider the effects that occur in the immediate (nearest neighbor) vicinity of a given base pair (bp) in a secondary structure plot. They are therefore defined as nearest-neighbor secondary structure (NNSS) strategies.

Functional specialization and evolution of leader proteinases in the family Closteroviridae.

Members of the Closteroviridae and Potyviridae families of the plant positive-strand RNA viruses encode one or two papain-like leader proteinases. In addition to a C-terminal proteolytic domain, each of these proteinases possesses a nonproteolytic N-terminal domain. We compared functions of the several leader proteinases using a gene swapping approach.

[Retinal hazard from blue light emitting diode].

Purpose: To compare the effect of exposure time from a blue(460 nm) light emitting diode(LED) on the morphology of the outer retina and determine conditions where damage occurs.

Materials And Methods: Young adult rhesus monkeys were anesthetized, and received blue LED exposure from a modified slit-lamp. A 3 mm beam of 0.

Characterization of the cis-acting elements controlling subgenomic mRNAs of citrus tristeza virus: production of positive- and negative-stranded 3'-terminal and positive-stranded 5'-terminal RNAs.

Citrus tristeza virus (CTV), a member of the Closteroviridae, has an approximately 20-kb positive-sense RNA genome with two 5' ORFs translated from the genomic RNA and 10 3' genes expressed via nine or ten 3'-terminal subgenomic (sg) RNAs. The expression of the 3' genes appears to have properties intermediate between the smaller viruses of the "alphavirus supergroup" and the larger viruses of the Coronaviridae. The sgRNAs are contiguous with the genome, without a common 5' leader, and are associated with large amounts of complementary sgRNAs.

Local fundus response to blue (LED and laser) and infrared (LED and laser) sources.

Light damage research began during the early years of laser light exploration. There is a clear and significant literature that identifies an easily demonstrated retina-pigment epithelium pathology which is associated with short wavelength exposures below 520 nm. Recent interest has expanded because of the growing evidence for a blue light contribution to the retina aging process by way of a poorly understood chemical process(es) that involve circulation, oxidative reactions and the spectral absorption properties of the pigment epithelium.

Deer Mice As Laboratory Animals.

Although laboratory mice (Mus) and rats (Rattus) are the most widely used research rodents, deer mice (Peromyscus maniculatus) and their congeneric species are favored as nontraditional alternatives for some purposes. Mice of the native genus Peromyscus are the most abundant and widely distributed rodents in North America. They occur in a great diversity of habitats and play a significant role in natural ecosystems.

Assessment of recombinants that arise from the use of a TMV-based transient expression vector.

A potential use of virus-based transient expression vectors is the large-scale production of commercial specialty products, which would require the inoculation of many acres of plants with the viral vector. However, there are several concerns about the widespread use of virus-based vectors. Among these are the spread of the engineered virus to susceptible plants and the generation and persistence of recombinant viruses in the environment.

Conundrum of the lack of defective RNAs (dRNAs) associated with tobamovirus Infections: dRNAs that can move are not replicated by the wild-type virus; dRNAs that are replicated by the wild-type virus do not move.

Two classes of artificially constructed defective RNAs (dRNAs) of Tobacco mosaic virus (TMV) were examined in planta with helper viruses that expressed one (183 kDa) or both (126 and 183 kDa) of the replicase-associated proteins. The first class of artificially constructed dRNAs had the helicase and polymerase (POL) domains deleted; the second had an intact 126-kDa protein open reading frame (ORF). Despite extremely high levels of replication in protoplasts, the first class of dRNAs did not accumulate in plants.