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At least 19 recordsLinked to original sources
PubMed2026

Amplification-Free Nanopore Sequencing for Herpesvirus DNA Detection in Intraocular Fluids.

PURPOSE: To evaluate the feasibility of amplification-free nanopore sequencing for detecting herpesvirus DNA in intraocular fluid using multiplex polymerase chain reaction (mPCR)-characterized herpesvirus-positive and herpesvirus-negative samples. DESIGN: Retrospective, single-center, cross-sectional study. PARTICIPANTS: This study included 42 patients with uveitis whose intraocular fluid samples were examined by mPCR, including 20 mPCR-positive samples (all positive for herpesviruses) and 22 mPCR-negative samples. METHODS INTERVENTION OR TESTING: DNA extracted from intraocular fluid samples underwent ligation-based library preparation without whole-genome amplification and was sequenced on the MinION platform with Flongle flow cells for untargeted analysis. Nanopore sequencing results were compared with mPCR findings, and associations between nanopore-derived virus-specific read counts and corresponding herpesvirus DNA copy numbers measured by mPCR were assessed. MAIN OUTCOME MEASURES: Primary outcome measure was concordance between nanopore sequencing and mPCR in herpesvirus species identification. Secondary outcome measures included nanopore sequencing detection rates stratified according to mPCR-measured herpesvirus DNA copy numbers and correlations between nanopore sequencing-derived virus-specific read counts and mPCR-measured herpesvirus DNA copy numbers. RESULTS: Among 20 mPCR-positive intraocular fluid samples, nanopore sequencing identified viral DNA from the same herpesvirus species detected by mPCR in 15 (75.0%), indicating species-level concordance. None of the 22 mPCR-negative samples contained virus-specific reads. Among the 22 herpesvirus targets identified in the 20 mPCR-positive samples, herpesvirus DNA copy numbers measured by mPCR were significantly higher in nanopore-positive than in nanopore-negative targets (P = 0.015). Nanopore detection rates increased with increasing herpesvirus DNA copy numbers measured by mPCR: 3 of 6 targets (50.0%) with <105 copies/mL, 2 of 4 (50.0%) with 105-106 copies/mL, and 12 of 12 (100%) with >106 copies/mL (P = 0.021). Nanopore sequencing-derived virus-specific read counts correlated positively with herpesvirus DNA copy numbers measured by mPCR (r = 0.76, P = 0.0004). CONCLUSIONS: Amplification-free nanopore sequencing demonstrated the feasibility of detecting herpesvirus DNA in intraocular fluid samples, with detection performance dependent on herpesvirus DNA load. This simplified workflow may provide complementary information regarding viral DNA burden in minute ocular samples. FINANCIAL DISCLOSURES: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Herpesvirus↗
PubMed1975

Experimental tonography on enucleated human eyes. II. The loss of intraocular fluid caused by tonography.

In clinical work, the loss of intraocular fluid caused by tonography (dV) is usually calculated according to the formula of Grant and Friedenwald. The validity of this formula has been tested by comparing the dV calculated from known factors in the formula with the dV measured directly on enucleated eyes. Our results show a good correlation between the two methods, especially when the rigidity coefficient at the beginning of tonography is used in the calculations. It is concluded from our experiments here and in our previous paper that the theoretical foundation of tonography in principle is valid.

Body Fluids↗
PubMed1975

Glycolytic enzyme levels of intraocular fluids and lens as compared to the respective sera of various animal species.

The levels of glycolytic enzymes, aldolase, phosphohexose isomerase and lactic dehydrogenase, the latter as total and isozymes, were determined in the vitreous and aqueous humors and sera as well as in lens-saline extracts of the cat, Rhesus monkey, guinea pig, rabbit, rat and cattle. Although wide species differences were noted, the levels were generally lower in the aqueous as compared to the vitreous and serum. Aldolase and phosphohexose isomerase were invariably elevated in the lens of most species. The LDH isozyme patterns were quite unique in regard to the fluids and the species. The ratios of enzyme contents of the intraocular fluids to the respective sera were calculated and the findings compared. As tested in a few species, no remarkable enzyme differences could be discerned as a result of prior dark or light adaptation of the eyes.

Animals↗
PubMedDate not supplied

The effect of parasympathetic nervous system on hydrodynamics of intraocular fluids and distribution of electrolytes and amino acids.

Tonographic determinations Po and C), cannulation of the anterior chamber and measurements of the secreted aqueous humor volume by the method of posterior-anterior chamber perfusion with inulin solution were carried out in normal eyes, in eyes after parasympathetic denervation and during the action of a cholinergic neurotransmitter under the conditions of postdenervation hyperexcitability. Parasympathetic denervation of the eyeball was obtained by excision of the ciliary ganglion. Additonally, pharmacological blockade of the adrenergic neurons was applied. In the aqueous humor from the posterior and anterior chamber osmolality, as well as concentrations of sodium potassium, calcium, magnesium and total alpha-amino nitrogen were determined. The cholinergic effect on the volume of secreted aqueous humor and on the channels of its outflow was described. This effect was enhanced by the postdenervation hyperexcitability state, indicating a stimulating parasympathetic influence on the passage of electrolytes and amino acids into the intraocular fluids.

Amino Acids↗
PubMed1975

Coenzyme specificity in the glycolysis of intraocular fluids.

Toward elucidation of the glycolysis in the vitreous and aqueous of several animal species, coenzymes of this scheme, NAD, NADH and ATP were assayed but found to be virtually absent. To further assess this pathway, ADP and NADPH in addition to the above were introduced singly and in combination with 0.20 ml-aliquots of the guinea pig aqueous and vitreous under anaerobic conditions and the absorbance followed spectrophotometrically at 340 nm. Only NADH produced an immediate observable response and the rate of change was greater for the virteous. The action of oxamate and iodacetate was also screened. The experiments point to the LDH-catalyzed step as responsible for the observed effect.

Adenosine Diphosphate↗
PubMedDate not supplied

Application of a minicomputer-based system in measuring intraocular fluid dynamics.

A complete, computerized system has been developed to automate and display radionuclide clearance studies in an ophthalmology clinical laboratory. The system is based on a PDP-8E computer with a 16-k core memory and includes a dual-drive Decassette system and an interactive display terminal. The software controls the acquisition of data from an NIM scaler, times the procedures, and analyzes and simultaneously displays logarithmically converted data on a fully annotated graph. Animal studies and clinical experiments are presented to illustrate the nature of these displays and the results obtained using this automated eye physiometer.

Animals↗
PubMed1975

Intraocular injection of balanced salt solution and/or air as aids in the release of subretinal fluid.

Intraocular BSS and air used in combination with buckling procedures and exoplants have been helpful as aids in the release of subretinal fluid. BSS can be injected into the anterior chamber or through the pars plana and the buckling area. Air should only be injected through the pars plana. The advantages are discussed. Careful technique is generally exempt of complications.

Adolescent↗
PubMed1977

In vitro evaluation of intraocular infusion fluids: effects on the lens and cornea.

Glutatione-bicarbonate-Ringer solution (GBR), GBR deficient in adenosine and glutathione, and a newly proposed glucose-phosphate-Ringer solution (GPR) have been found to maintain lens function and corneal endothelial viability with approximately equal efficacy during prolonged periods of incubation. Currently used intraocular irrigating solutions do not perform as well in maintaining the function of borderline decompensated lenses and in sustaining endothelial viability.

Animals↗
PubMed1977

The state of eye hydrocircular system in view of age pathology and open-angle glaucoma.

With age the eye drainage system undergoes a number of changes because less favorable conditions arise for intraocular fluid reflux. The manifestation and extent of these changes were closely connected with the manifestation of arteriosclerotic affection of the cardiovascular system. The changes in eye drainage passages in persons with pronounced complicated arteriosclerosis and advanced open-angle glaucoma were identical in character and comparable in the manifestation. The changes in eye drainage passages in persons with pronounced arteriosclerosis and open-angle glaucoma did not have the character of isolated trabecular lesion or lesions of Schlemm's canal or intrascleral tracts, but they were detected in all these sectors. The obtained data indicate that the changes in the eye drainage system connected with age pathology an open-angle glaucoma took place and were more pronounced in the superior sectors of the eye, gradually spreading downward. The conditions for intraocular fluid reflux along the primary tracts being deteriorated, its reflux appears to increase through the uveal tract.

Adult↗
PubMed1979

An experimental approach to the study of intraocular Toxocara canis.

An experimental study of nematode endophthalmitis due to T canis and review of the literature has been presented. Six owl monkeys were infected either by nasogastric tube using embryonated T canis eggs or by carotid or intravitreal injection of second stage larvae. The clinical manifestations, especially ocular, were observed and various diagnostic tests performed. Only minimal or no intraocular changes were seen after systemic infection but significant abnormalities such as retinal hemorrhages and venous dilation were noted after intravitreal infection. Motile larvae were observed in the lenses of three eyes and in the vitreous of five eyes and, probably a sixth, after intravitreal injection. The intensity and timing of the intraocular reaction seemed to correlate with the infecting dose and apparent disappearance of larvae from the eye. Pathologic confirmation of larvae in the lens was obtained in one eye. A marked inflammatory reaction occurred in eyes receiving intraocular infection but none was seen in eyes with only systemic infectin. Various laboratory and serologic studies were performed, including the ELISA test, which were used to evaluate systemic as well as intraocular responses to infection with T canis. The two monkeys infected by nasogastric tube gave a positive ELISA response in the serum but intraocular fluids gave a negative response in all monkeys including those infected syst:mically and/or intraocularly. Problems in the understanding of clinical aspects of the disease, laboratory diagnosis and treatment are discussed. The need for future experimental studies is emphasized.

Adult↗
PubMed1975

[An attack of glaucoma after a cataract operation associated with pigment degeneration of the retina (author's transl)].

From four cases the appearance of acute glaucoma attacks after cataract-operation in association with pigment degeneration of the retina is described. We could show in none of the cases the previous presence of glaucoma. It is concluded from this there is an increased danger of an acute pressure rise in operative procedures in association with pigment degeneration of the cornea as a result of dysregulation of the intraocular fluid mechanics. Appropriate preventive measures are recommended.

Adult↗