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N R Miller

Publications and source records attributed to N R Miller.

At least 163 records · Page 9Linked to original sources

Inverse correlation between dexamethasone 21-mesylate agonist activity and sensitivity to dexamethasone for induction of tyrosine aminotransferase in rat hepatoma cells.

Previous results demonstrated that both the level of induction of the liver specific enzyme tyrosine aminotransferase (TAT) by the irreversible antiglucocorticoid dexamethasone 21-mesylate (Dex-Mes) and the concentration of the reversible glucocorticoid dexamethasone (Dex) required for 50% of maximal TAT induction (i.e. EC50) were different in HTC and Fu5-5 rat hepatoma culture cells. In the present study, a retrospective analysis of these two parameters over an 8 yr period indicates that the absolute values of both parameters varied within each cell line over time in a reversible manner. The variation of both parameters appears to be causally related since a linear, reciprocal relationship exists between the amount of Dex-Mes agonist activity and log10 (Dex EC50) in both cell lines (correlation coefficient is -0.896 for n = 46). This relationship was independent of changes in basal TAT level, culture medium, and serum lot. Results with cloned HTC cells indicate that these temporal variations are not due to fluctuations in the relative abundance of two cell populations displaying either high or low amounts of agonist activity with Dex-Mes. While these analyses relied on the detection of enzyme levels, the amount of TAT mRNA is shown to parallel the enzyme levels. Thus the variation in parameters of TAT induction by Dex and by Dex-Mes appears to be modulated at a pre-translational step. Such variations have not previously been observed for the control of specific gene transcripts by other steroid hormones and may be related to the known differences in agonist activity seen for most antisteroids in various systems.

Animals↗

Intraobserver and interobserver agreement in measurement of optic disc characteristics.

Reliable measures of optic nerve status are important parameters for epidemiologic and clinical studies of glaucoma. Stereo fundus photography has been used to reduce interobserver variation, but little data have been reported quantifying the level of agreement in these situations. This article examines chance-corrected intraobserver and interobserver agreement for horizontal and vertical cup:disc ratios and width of the narrowest remaining neuroretinal rim on stereo, color, fundus photographs. Intraobserver agreement was substantial to almost perfect for both readers (kappas between 0.82 and 0.86 for horizontal and vertical cup:disc ratios and 0.71 for the neuroretinal rim). Interobserver agreement was also substantial (kappas of 0.71 for horizontal cup:disc ratio, 0.74 for vertical cup:disc ratio, and 0.58 for the neuroretinal rim). Both intraobserver and interobserver agreement were best for glaucoma patients followed by ocular hypertensives and controls. Dichotimizing cup:disc ratios into suspicious or not suspicious using a range of cutoff points (greater than or equal to 0.5, greater than or equal to 0.6, and greater than or equal to 0.7 disc diameters [DD]) had little effect on agreement levels. Estimation of the status of the optic nerve is complex, requiring judgment about the shape and structure of the cup. Agreement is optimized by using stereo photographs, using the same observer and, when evaluating progression, comparing photographs from different points in time at a single sitting.

Glaucoma↗

Pinealoma.

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Brain Neoplasms↗

Intracranial oculomotor nerve paresis with anisocoria and pupillary parasympathetic hypersensitivity.

Three patients developed anisocoria as a result of third nerve palsies caused by intracranial lesions: two in the cavernous sinus and one in the mesencephalon. Pharmacologic testing using low concentration pilocarpine showed apparent preganglionic parasympathetic supersensitivity of the abnormal pupil. These findings are compatible with the existence of a proposed direct pathway from the midbrain to the eye, without synapse at the ciliary ganglion. Cholinergic hypersensitivity can occur, not only with postciliary ganglionic but also with preciliary ganglionic parasympathetic lesions.

Adult↗

Does neuroretinitis rule out multiple sclerosis?

Neuroretinitis, a form of optic neuritis, is characterized by papillitis and a stellate macular exudate, or "macular star." The star implies the presence of a disc vasculopathy and secondary leakage of lipoproteinaceous material into the macula. Demyelinating optic neuritis would not be expected to produce a secondary macular exudate. We reviewed the literature on the risk of multiple sclerosis developing in a patient after an attack of optic neuritis, and rarely found a comment on the presence of a macular star. We then reviewed two series of 40 patients who had neuroretinitis and added ten patients of our own. Signs of multiple sclerosis had not developed in the 13 patients contacted retrospectively, nor in the patients followed up prospectively. We also noted that in our patients, neuroretinitis may be accompanied by other neurologic manifestations; neuroretinitis may be bilateral and may be staggered; papillitis may present without a macular star, only to have typical exudates develop up to two weeks later; and the macular exudate may take up to 12 months to resolve. We suggest that patients who demonstrate acute papillitis with a normal macula be reevaluated within two weeks for the development of a macular star. Its presence militates strongly against the subsequent development of multiple sclerosis.

Fundus Oculi↗

Typing of herpes simplex virus by capture biotin-streptavidin enzyme-linked immunosorbent assay and comparison with restriction endonuclease analysis and immunofluorescence method using monoclonal antibodies.

A sensitive enzyme-linked immunosorbent capture assay using biotin and streptavidin (capture B/SA ELISA) was developed using type-specific monoclonal antibodies for typing of herpes simplex virus. Rabbit anti-herpes simplex virus immunoglobulin G was used as the capturing antibody, and biotin-linked type-1-specific mouse monoclonal antibody or rabbit type-1- or type-2-specific polyclonal antibody served as the detecting antibody. The captured antigen was detected by an ELISA with alkaline phosphatase-conjugated streptavidin, which reacted with biotin molecules on the detector antibody. The capture B/SA ELISA was compared with other methods for efficiency and reliability in typing. Results obtained by restriction endonuclease digestion of the radiolabeled viral genome were used to determine the type (1 or 2) of clinical isolates. These results were then used as a reference for determining the accuracy of the capture B/SA ELISA, as well as that of the immunofluorescence method, both of which are easily adaptable for use in the clinical laboratory. The three methods were in perfect agreement. It was determined that both the capture B/SA ELISA and the immunofluorescence method using monoclonal antibodies provided typing results with 100% specificity and 100% sensitivity and thus were accurate and reliable. However, the ELISA was the method of choice because of its simplicity, rapidity, and use of nonradioisotopic reagents.

Antibodies, Monoclonal↗

Involvement of orbital tissues by sarcoid.

Of 15 biopsy specimens identified as showing sarcoid involving the extraocular orbital tissues, three were from patients known to have systemic sarcoidosis before biopsy. Of the other 12 patients who were not known to have systemic disease at the time of biopsy, 11 were found to have evidence of systemic sarcoidosis after the biopsy. One patient, however, had no evidence of sarcoidosis at the time of the biopsy nor did she develop sarcoidosis during a seven-year follow-up period. Our results suggest that most patients with sarcoid involving the orbit will be found to have evidence of systemic sarcoidosis, but that rare patients exist in whom the orbital lesion appears to represent an isolated process. There was no histologic difference between orbital specimens from patients with systemic sarcoidosis and the specimens from the patient with isolated sarcoid of the orbit.

Adult↗

Optic neuropathy in systemic lupus erythematosus.

We report data from seven cases of optic neuropathy in systemic lupus erythematosus. The visual outcome varied, but improvement occasionally occurred following treatment with corticosteroids. The clinical picture was variable and could present as acute retrobulbar optic neuritis, ischemic optic neuropathy, or slowly progressive visual loss. Visual evoked response testing revealed increased latency in two patients and loss of amplitude in two others; a fifth patient had both findings in the involved eye. Despite the variable presentation, the probable pathogenesis in all cases is vaso-occlusive disease in small vessels of the optic nerves.

Adult↗

Computed tomographic three-dimensional localization and compositional evaluation of intraocular and orbital foreign bodies.

A software program designed for the Siemens Somatom DR3 computed tomographic (CT) scanner provides improved diagnosis, localization, and etiologic description of intraocular and orbital foreign bodies. The program allows information to be analyzed in two different display formats. One format is that of multiplanar reconstruction of the eye and orbit, including an "oblique CT cube" image. This format produces an accurate "three-dimensional" display of both in vitro and in vivo intraocular and orbital foreign bodies. The second display format is that of a histogram. Using this analytic mode, nonmetallic intraocular and intraorbital foreign bodies can be differentiated from each other and from metallic foreign bodies, although individual metallic foreign bodies cannot be identified with respect to specific composition. The information provided by these two display formats substantially aids the clinician in the diagnosis and management of foreign bodies located within the orbit, particularly those located within the eye.

Animals↗

Temporal arteritis. A clinicopathologic study.

Clinical and laboratory findings of 237 consecutive patients who had 250 temporal artery biopsies performed at the Wilmer Institute during a 15-year period were reviewed. Biopsies were reviewed independently on three separate occasions by four observers who, unaware of the clinical history, made one of the following histopathologic diagnoses: active arteritis, healed arteritis, arteriosclerosis, atherosclerosis, normal, or other. Biopsies were reviewed a fourth time by the observers together to establish a consensus diagnosis. The frequency of intraobserver disagreement in biopsy interpretation ranged from 4.4 to 25.6% of cases. The frequency with which observers disagreed with the consensus diagnosis (interobserver variation) ranged from 4.3 to 13.5% of cases. Pre-biopsy steroid therapy for seven to eight weeks or longer was associated with loss of the histopathologic features of active arteritis. We recommend biopsies for all patients with known contraindications to steroid therapy. In addition, multivariant regression analysis suggests that certain patients can be selected who are likely to have positive biopsies. For some patients, the clinical diagnosis of temporal arteritis can be based on the clinical signs and symptoms and their response to a therapeutic trial of steroids.

Aged↗

Ectopic brain in the orbit.

We report a case of ectopic brain tissue in the orbit associated with a bony defect of the orbit and the presence of skeletal muscle. Previous reports of orbital ectopic brain and related lesions in the orbit and at other sites are reviewed.

Brain↗

Ocular features of carotid occlusive disease.

This article presents the clinicopathologic features of five patients with ocular involvement secondary to carotid artery disease. Three patients had the features of hypotensive retinopathy and two had panocular ischemia. In demonstrating the possible ocular and nonocular sequelae of carotid artery disease, this study stressed the importance of the recognition of the variable ocular features associated with carotid artery occlusive disease.

Aged↗

The pattern of optic nerve fiber loss in anterior ischemic optic neuropathy.

Postmortem quantification of the remaining optic nerve fibers in three eyes with nonarteritic anterior ischemic optic neuropathy showed that the loss of fibers was complete in the superior half of each nerve and included loss of peripheral fibers in the other half. The fibers with the greatest resistance to atrophy were found in the middle of the nerve cross section. The pattern was similar to that found in a previous example of anterior ischemic optic neuropathy and unlike that found in glaucoma or other optic neuropathies studied in similar fashion.

Aged↗