scholarly journals Relationships between Intraocular Pressure, Effective Filtration Area and Morphological Changes in the Trabecular Meshwork of Steroid-Induced Ocular Hypertensive Mouse Eyes

2022 ◽  
Vol 23 (2) ◽  
pp. 854
Author(s):  
Ruiyi Ren ◽  
Anne A. Humphrey ◽  
David L. Swain ◽  
Haiyan Gong
Keyword(s):  
Electron Microscopy ◽  
Intraocular Pressure ◽  
Trabecular Meshwork ◽  
Inverse Relationship ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Eye Drops ◽  
Fluorescent Tracers ◽  
Filtration Area ◽  
The Mean

We investigated whether an inverse relationship exists between intraocular pressure (IOP) and effective filtration area (EFA) in the trabecular meshwork (TM) in a steroid-induced ocular hypertensive (SIOH) mouse model and the morphological changes associated with the reduction of EFA. C57BL/6 mice (n = 15 per group) received either 0.1% dexamethasone (DEX) or saline eye drops twice daily for five weeks. IOP was measured weekly. Fluorescent tracers were injected into the anterior chamber to label EFA at the endpoint. Injected eyes were fixed and processed for confocal microscopy. EFA in the TM was analyzed. Light and electron microscopy were performed in high- and low-tracer regions of six eyes per group. The mean IOP was ~4 mm Hg higher in DEX-treated than saline-treated control eyes (p < 0.001) at the endpoint. EFA was reduced in DEX-treated eyes compared to controls (p < 0.01) and negatively correlated with IOP (R2 = 0.38, p = 0.002). Reduced thickness of juxtacanalicular tissue (JCT) and increased abnormal extracellular matrix in the JCT were found to be associated with reduced EFA. Our data confirm the inverse relationship between EFA and IOP, suggesting that morphological changes in the JCT contribute to the reduction of EFA, thus elevating IOP in SIOH mouse eyes.

scholarly journals A Case of Iris Melanocytoma Demonstrating Diffuse Melanocytic Proliferation with Uncontrolled Intraocular Pressure

2017 ◽  
Vol 8 (1) ◽  
pp. 190-194 ◽  
Author(s):  
Mami Kusunose ◽  
Yuji Sakino ◽  
Yoshihiro Noda ◽  
Tsutomu Daa ◽  
Toshiaki Kubota
Keyword(s):  
Electron Microscopy ◽  
Intraocular Pressure ◽  
Tumor Cells ◽  
Trabecular Meshwork ◽  
Light And Electron Microscopy ◽  
Secondary Glaucoma ◽  
Pigment Dispersion ◽  
Large Tumor ◽  
History Of ◽  
Ring Melanoma

We report a rare case with histologically proven melanocytoma of the iris that demonstrated diffuse melanocytic proliferation with uncontrolled secondary glaucoma and investigate the etiology of the intraocular pressure elevation. The patient was a 78-year-old man with a history of darkened iris of his left eye. The intraocular pressure was 39 mm Hg. A slit-lamp examination showed a diffuse darkened iris, and a gonioscopic examination revealed open angle with circumferential heavy pigmentation. There was no pigment dispersion of the anterior chamber and no pigment deposition of the cornea. We suspected malignant ring melanoma in the left eye and enucleated it. The globe was examined with light and electron microscopy. Light microscopy revealed the presence of heavily pigmented tumor cells in the iris, ciliary body, trabecular meshwork, and Schlemm’s canal. A bleached preparation showed large tumor cells with central and paracentral nuclei without mitosis. Electron microscopy of the trabecular meshwork revealed melanin-bearing tumor cells invading the intertrabecular spaces, and the melanin granules were not phagocytosed in the trabecular cells. The mechanical obstruction of the aqueous flow by the tumor cells may be a major cause of secondary glaucoma in eyes with iris melanocytoma presenting diffuse proliferation.

scholarly journals Morphological changes in the trabecular meshwork and Schlemm’s canal after treatment with topical intraocular pressure-lowering agents

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji-Hye Park ◽  
Hyun Woo Chung ◽  
Eun Gyu Yoon ◽  
Min Jung Ji ◽  
Chungkwon Yoo ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Trabecular Meshwork ◽  
Morphological Changes ◽  
Open Angle Glaucoma ◽  
Anterior Segment ◽  
Schlemm’S Canal ◽  
Schlemm's Canal ◽  
Before And After ◽  
Treatment Naïve ◽  
Aqueous Outflow

AbstractGlaucoma treatment is usually initiated with topical medication that lowers the intraocular pressure (IOP) by reducing the aqueous production, enhancing the aqueous outflow, or both. However, the effect of topical IOP-lowering medications on the microstructures of the aqueous outflow pathway are relatively unknown. In this retrospective, observational study, 56 treatment-naïve patients with primary open-angle glaucoma were enrolled. Images of the nasal and temporal corneoscleral limbus were obtained using anterior segment optical coherence tomography (AS-OCT). The conjunctival vessels and iris anatomy were used as landmarks to select the same limbal area scan, and the trabecular meshwork (TM) width, TM thickness, and Schlemm’s canal (SC) area were measured before and after using the IOP-lowering agents for 3 months. Among the 56 patients enrolled, 33 patients used prostaglandin (PG) analogues, and 23 patients used dorzolamide/timolol fixed combination (DTFC). After 3 months of DTFC usage, the TM width, TM thickness, and SC area did not show significant changes in either the nasal or temporal sectors. Conversely, after prostaglandin analog usage, the TM thickness significantly increased, and the SC area significantly decreased (all P < 0.01). These findings warrant a deeper investigation into their relationship to aqueous outflow through the conventional and unconventional outflow pathways after treatment with PG analogues.

scholarly journals Ultrastructural analysis of the spermatogenesis in the guinea pig (Cavia porcellus)

2016 ◽  
Vol 36 (suppl 1) ◽  
pp. 89-94 ◽  
Author(s):  
Luciana S. Simões ◽  
Rose E.G. Rici ◽  
Phelipe O. Favaron ◽  
Taís Harumi de Castro Sasahara ◽  
Rodrigo S.N. Barreto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Guinea Pig ◽  
Sexual Development ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Management Systems ◽  
Cavia Porcellus ◽  
Reproductive Parameters ◽  
Development Stages ◽  
Transmission Electron

Abstract: al for both, the establishment of appropriate management systems, and for the use of new species as animal models. In this study, we used light and electron microscopy to characterize the sexual development stages of the guinea pig (Cavia porcellus) in specimens of 30, 45 and 90 days of age. We observed the differentiation of spermatocytes only through transmission electron microscopy in the leptotene, zygotene and pachytene phases of meiosis, in 30-day-old animals. During puberty, there was differentiation of the germinative epithelium and formation of the acrosome. Spermatozoa, however, were not detected. Thus, we could infer that puberty happens after 45 days of age. Sexual maturity was evident in 90-day-old specimens. Our results showed that changes in the testicular germinative epithelium during the postnatal sexual development in guinea pig led to morphological changes, including the ones related to the development of Leydig and Sertoli cells, which are directly related to puberty. In this work, we provide new morphological subsidies for a better understanding of reproductive parameters of this species, enabling its use as an animal model in the field of the reproductive biology.

scholarly journals Light and electron microscopy characteristics of the muscle of patients with SURF1 gene mutations associated with Leigh disease

2007 ◽  
Vol 61 (4) ◽  
pp. 460-466 ◽  
Author(s):  
M Pronicki ◽  
E Matyja ◽  
D Piekutowska-Abramczuk ◽  
T Szymańska-Dębińska ◽  
A Karkucińska-Więckowska ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lipid Accumulation ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Gene Mutations ◽  
Leigh Syndrome ◽  
Typical Feature ◽  
Ultrastructural Changes ◽  
Consistent Feature ◽  
Muscle Changes

Aims:Leigh syndrome (LS) is characterised by almost identical brain changes despite considerable causal heterogeneity. SURF1 gene mutations are among the most frequent causes of LS. Although deficiency of cytochrome c oxidase (COX) is a typical feature of the muscle in SURF1-deficient LS, other abnormalities have been rarely described. The aim of the present work is to assess the skeletal muscle morphology coexisting with SURF1 mutations from our own research and in the literature.Methods:Muscle samples from 21 patients who fulfilled the criteria of LS and SURF1 mutations (14 homozygotes and 7 heterozygotes of c.841delCT) were examined by light and electron microscopy.Results:Diffuse decreased activity or total deficit of COX was revealed histochemically in all examined muscles. No ragged red fibres (RRFs) were seen. Lipid accumulation and fibre size variability were found in 14 and 9 specimens, respectively. Ultrastructural assessment showed several mitochondrial abnormalities, lipid deposits, myofibrillar disorganisation and other minor changes. In five cases no ultrastructural changes were found. Apart from slight correlation between lipid accumulation shown by histochemical and ultrastructural techniques, no other correlations were revealed between parameters investigated, especially between severity of morphological changes and the patient’s age at the biopsy.Conclusion:Histological and histochemical features of muscle of genetically homogenous SURF1-deficient LS were reproducible in detection of COX deficit. Minor muscle changes were not commonly present. Also, ultrastructural abnormalities were not a consistent feature. It should be emphasised that SURF1-deficient muscle assessed in the light and electron microscopy panel may be interpreted as normal if COX staining is not employed.

Coarsening Kinetics of B2 Precipitate Particles in an Elastically Constrained Fe-Al-Co Alloy

2004 ◽  
Vol 449-452 ◽  
pp. 521-524
Author(s):  
T. Maebashi ◽  
Minoru Doi ◽  
Takao Kozakai
Keyword(s):  
Electron Microscopy ◽  
Early Stage ◽  
Morphological Changes ◽  
Ageing Time ◽  
Cube Root ◽  
Transmission Electron ◽  
The Mean ◽  
Coarsening Kinetics ◽  
Means Of Transmission ◽  
Kinetics Of

The morphological changes and the coarsening kinetics of B2 particles in A2 matrix in the elastically constrained Fe-16at%Al-18at%Co alloy were investigated by means of transmission electron microscopy (TEM). The mean particle radius increases in proportion to the cube root of ageing time at early stage, then the coarsening of B2 particle decelerate at late stage of aging. And it clarified the decelerated coarsening in Fe based alloy also is related to the change in PSD and is caused by the elastically strained effect.

Endodermal formation in blastocytes of the marsupials Isoodon macrousus and Perameles nasuta

1977 ◽  
Vol 25 (2) ◽  
pp. 207 ◽  
Author(s):  
DE Hollis ◽  
AG Lyne
Keyword(s):  
Electron Microscopy ◽  
Outer Surface ◽  
Zona Pellucida ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Didelphis Virginiana ◽  
Continuous Layer ◽  
Shell Membrane ◽  
American Opossum ◽  
Embryonic Region

Eleven embryos, ranging from partly to fully bilaminar blastocysts, were obtained from the bandicoots I. macrourus and P. nasuta and were examined by light and electron microscopy. The morphological changes which occurred during the differentiation of the endoderm and ectoderm are described. The shell membrane was thinner than it was in unilaminar blastocysts and had a deposit of material of irregular thickness on its outer surface. The mucoid coat and zona pellucida were absent or discontinuous. Endoderm formation was first observed in blastocysts about 1.0 mm in diameter. Cells migrated inwards from regions of thickened protoderm to form a continuous layer of similar flattened cells - the endoderm - beneath the protoderm, which then became the ectoderm. The blastocysts were fully bilaminar when they were 1.5-1.9 mm in diameter. At this stage the ectoderm was composed of two distinct regions, an embryonic region of cuboidal cells and a non-embryonic region of flattened cells resembling the cells of the endoderm. The formation of the endoderm in bandicoots closely resembles that described in other marsupials, except the American opossum Didelphis virginiana in which endoderm cells are released into the blastocoele before they form a continuous layer.

Prospective study comparing Xalatan® eye drops and two similar generics as to the efficacy and safety profile

2018 ◽  
Vol 28 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Andreas Diagourtas ◽  
Kostantinos Kagelaris ◽  
Kostantinos Oikonomakis ◽  
Andreas Droulias ◽  
Nikolaos Kokolakis ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Safety Profile ◽  
Ocular Surface ◽  
Disease Index ◽  
Ocular Surface Disease ◽  
Eye Drops ◽  
Efficacy And Safety ◽  
Ocular Surface Disease Index ◽  
Significant Difference ◽  
The Mean

Purpose: To evaluate the efficacy and safety between two generic prostaglandins Lataz–Xalaprost (Greece) and the corresponding original drops (Xalatan®). Material and methods: In this prospective randomized study, 60 patients diagnosed with open-angle glaucoma or ocular hypertension were enrolled, who had never received antiglaucoma treatment. Subjects were divided randomly into three groups (Xalatan, Lataz, and Xalaprost groups) and they were studied over 16 weeks. At each visit, the mean applanation tonometry values and tear break-up time were measured. The Ocular Surface Disease Index questionnaire was used to evaluate patient’s symptoms. Results: There was a statistically significant difference (p < 0.001) in the mean values of the intraocular pressure between the baseline and the last visit (Xalatan group: from 23.11 ± 1.61 mmHg to 15.81 ± 1.22 mmHg, Lataz group: from 23.26 ± 1.33 mmHg to 15.80 ± 1.47 mmHg, and Xalaprost group: from 23.08 ± 1.45 mmHg to 16.08 ± 1.38 mmHg). Both generic eye drops showed mean percentage intraocular pressure reduction comparable to the standards of prostaglandin analogues (Xalatan: 31.57%, Lataz: 32.06%, and Xalaprost: 30.34%). Xalatan reduced the tear break-up time less, followed by Lataz and then by Xalaprost (Xalatan: from 8.5 to 8 s, Lataz: from 8.2 to 7.4 s, and Xalaprost: from 8.7 to 7.7 s). Xalatan presented the best safety profile, followed by Lataz and least was Xalaprost, according to Ocular Surface Disease Index questionnaire’s results. Conclusion: No significant difference was recorded in the effectiveness of each generic prostaglandin compared to the original. Furthermore, no patient had to change medication. The differences that arose in the safety profile of the three eye drops suggest a prompt closer initial monitoring of patients who are administered generic eye drops.

Glomerulonephropathies in Plasmodium inui-infected rhesus monkey: a primate model and possible applications for human quartan malaria

Parasitology ◽  
2014 ◽  
Vol 141 (12) ◽  
pp. 1638-1645 ◽  
Author(s):  
L. F. NIMRI ◽  
H. N. LANNERS
Keyword(s):  
Electron Microscopy ◽  
Rhesus Monkey ◽  
Mesangial Cells ◽  
Morphological Changes ◽  
Clinical Chemistry ◽  
Light And Electron Microscopy ◽  
Histopathological Changes ◽  
Primate Model ◽  
Nephritic Syndrome ◽  
Plasmodium Inui

SUMMARYNone of the few animal models proposed for the study of human quartan malaria nephritic syndrome have shown complete pathological findings that are similar to those seen in humans. This study investigated the histopathological changes in kidneys in 10 Plasmodium inui infected Macaca mulatta monkeys by light and electron microscopy in order to develop a suitable animal model for human quartan malaria. Ten healthy adult rhesus monkeys were infected with P. inui and clinical chemistry and haematologic tests were done before and after infection. A renal biopsy sample was collected before infection as a baseline control and another biopsy was collected after infection. Histopathological changes examined by light and transmission electron microscopy (TEM) revealed abnormalities in all infected monkeys to variable degrees. Several electron-dense discrete or diffused mesangial deposits, and increase in mesangial cells and matrix were associated with the morphological changes observed by light microscope. This pattern is consistent with membranoproliferative glomerulonephritis type reported in humans infected with Plasmodium malariae. Results strongly support that the P. inui-infected rhesus monkey develop an immune-complex-mediated glomerulonephritis in the course of the infection. Therefore, this experimental model represents a useful tool to better understand the different parameters and the consequences of quartan malaria infections comparable to situations in humans.

scholarly journals Canaloplasty in Pigmentary Glaucoma: Long-Term Outcomes and Proposal of a New Hypothesis on Its Intraocular Pressure Lowering Mechanism

2020 ◽  
Vol 9 (12) ◽  
pp. 4024
Author(s):  
Paolo Brusini ◽  
Veronica Papa
Keyword(s):  
Intraocular Pressure ◽  
Trabecular Meshwork ◽  
Long Term Results ◽  
Pigmentary Glaucoma ◽  
Long Term Outcomes ◽  
Pressure Lowering ◽  
Visual Field Damage ◽  
The Mean ◽  
New Hypothesis

This study presents the long-term results on canaloplasty in a group of patients affected by pigmentary glaucoma, and studies the progression of the disease after surgery. Material and methods: Twenty-nine eyes of 25 patients with pigmentary glaucoma in maximum tolerated medical therapy with significant visual field damage progression underwent canaloplasty and were followed up to 11 years (mean 59.8 ± 30.1 months). All patients underwent a complete ophthalmic examination every 6 months. Results: The pre-operative mean intraocular pressure (IOP) was 31.8 mmHg ± 10.9 (range 21–70) with an average of 3.3 medications. After 1, 2, 3, and 4 years, the mean IOP was 15.9 ± 4.0, 14.4 ± 7.3, 14.1 ± 2.1, and 15.7 mmHg, respectively, with 0.4, 0.5, and 0.7 medications, respectively. Four patients underwent trabeculectomy after 3 to 30 months due to uncontrolled IOP. Gonioscopy showed a significant reduction of pigment in trabecular meshwork in all cases, starting from the sixth month. In some cases, the pigment was almost completely reabsorbed after two years, suggesting an accelerated transit and escape of the granules through the trabecular spaces. Conclusions: Canaloplasty seems to be a reasonable option in treating patients affected by progressive pigmentary glaucoma. The reabsorption of pigment granules from the trabecular meshwork could, at least in part, explain the relatively high success rate observed after this surgical procedure.

scholarly journals AUTOIMMUNE HEPATITIS: MORPHOLOGICAL ASPECTS

2021 ◽  
Vol 5 (1) ◽  
pp. 5-16
Author(s):  
V. M. Tsyrkunov ◽  
◽  
N. I. Prokopchik ◽  
V. P. Andreev ◽  
◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Autoimmune Hepatitis ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Morphological Aspects

The review presents literature data on the main pathomorphological features of autoimmune hepatitis (AIH) and the findings of light and electron microscopy in the form of photographs and descriptions of different variants of hepatic morphological changes in patients with AIH. Updates to the sections of the AIH classification concerning the etiology and origin of AIH are suggested, clinical examples are given with a description of the morphology features according to the classification specified by the authors.

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