Effects of a Long-Acting Diquafosol Ophthalmic Solution on the Ocular Surface, Tolerability, and Usability in Dry Eye Disease

INTRODUCTION

This study aimed to investigate the tolerability of high-viscosity diquafosol tetrasodium (DQS) ophthalmic solution (DIQUAS LX; DQSLX) and examine its usability and effect on clinical findings in patients with dry eye disease (DED).

METHODS

This interventional retrospective study included 66 eyes of 66 patients with DED who switched from conventional DQS to DQSLX ophthalmic solution. Tear function assessments (tear film breakup time [BUT], keratoconjunctival vital staining [VS] score), evaluations of DED symptom relief, and a four-item usability questionnaire ("comfort upon instillation," "irritation upon instillation," "eye mucus discharge," "convenience of instillation frequency") assessed using a visual analog scale from 0 (worst) to 10 (best) were administered 4 weeks after switching to DQSLX. Factors associated with drug tolerability were assessed using multiple regression analysis.

RESULTS

The symptoms improved by 64.2% after switching to DQSLX. The BUT value, VS score, and the questionnaire items "comfort upon instillation" and "convenience of instillation frequency" were significantly improved after switching to DQSLX. DQSLX tolerability was reported as acceptable in 56 (84.8%) and unacceptable in 10 (15.2%) patients. Overall, DQSLX tolerability was significantly associated with "comfort upon instillation" and "convenience of instillation frequency" and tended to be associated with a VS score ≥ 1. DQSLX tolerability depended on symptom and VS score improvements and absence of excessive "eye mucus discharge" in patients with a VS score ≥ 1 (39 patients), but on "comfort upon instillation" and absence of excessive "eye mucus discharge" in patients with a VS score = 0 (27 patients).

CONCLUSION

The high-viscosity DQSLX ophthalmic solution was generally considered acceptable in the study population. However, drug tolerability seemingly differed between patients with DED with and without epithelial damage. The former were affected by improvements in symptoms and clinical findings, whereas the latter were affected by comfort upon instillation.

TRIAL REGISTRATION

University Hospital Medical Information Network identifier, UMIN000051390.

A cryptic root isolate belonging to Geoglossales from potted Rhododendron: its molecular phylogeny and ability to colonize an ericoid mycorrhizal host in vitro

Although the lifestyle of Geoglossales remains largely unknown, recent advancements have established a hypothesis regarding the ericoid mycorrhizal lifestyle of geoglossoid fungi. In this study, we focused on one isolate of Geoglossales sp. obtained from surface-sterilized roots of potted Rhododendron transiens. We aimed to reveal the phylogenetic position and in vitro colonizing ability of this species in the hair roots of ericoid mycorrhizal plants. Based on our multigene phylogenetic tree, this species is a sister of the genus Sarcoleotia which has not been reported from either other studies or field environment. Its ascocarps could not be obtained, and conspecific sequences were not found in the databases and repositories examined. The Geoglossales sp. colonized the vital rhizodermal cells of blueberries in vitro with hyphal coils. There were relatively large morphological variations of coils consistent with extraradical hyphae; however, overall, the colonization morphologically resembled those by Sarcoleotia globosa and representative ericoid mycorrhizal fungi. The taxonomy and ecological significance of the species remain to be resolved; nevertheless, our results suggest that the ericoid mycorrhizal lifestyle may be widespread within Geoglossales.

Fluorescein Diacetate Vital staining for detecting viability of acid-fast bacilli in sputum of pulmonary tuberculosis patients

OBJECTIVE

To compare the performance of the Fluorescein diacetate (FDA) vital staining method with Ziehl-Neelsen staining method in detecting the viability of acid-fast bacilli using MGIT culture as "reference standard".

METHODS

This was a single centre prospective observational study conducted from October 2015 to November 2016. Microbiologically confirmed ZN-Smear positive (3+) sputum specimens were obtained from 30 pulmonary tuberculosis patients taking anti-tuberculosis treatment at DOTS centre of NITRD, New Delhi. Patients were made available to collect the first baseline sputum sample before commencing treatment, and an early morning sputum sample was collected as per RNTCP guidelines. After starting treatment, sputum specimens were collected weekly in the first month and thereafter twice-weekly until 18th week. All sputum specimens from patients receiving anti-tuberculosis treatment were examined using Ziehl-Neelsen (ZN) smear microscopy, FDA vital staining, and MGIT culture.

RESULT

Out of 360 follow up sputum specimens collected from 30 adult microbiologically confirmed ZN- Smear (3+) pulmonary tuberculosis patients, 146 were ZN-positive and 130 FDA-positive. Of 130 FDA-positive sputum samples, mycobacteria tuberculosis (MTB) growth was found in 116 sputum samples, of which 116 sputum specimens were positive for FDA. Additionally, 14 culture-negative specimens were FDA positive. No FDA-negative sputum samples were positive for MGIT culture. Among ZN positive specimens, FDA had 100% sensitivity and 85.3% specificity with an accuracy of 96.58% for the detection of viable mycobacteria. Among ZN negative sputum specimens, FDA had comparatively high specificity (95.7%). Using positive MGIT culture as a reference for viability, negative predictive value (NPV) and positive predictive value (PPV) from FDA vital staining method were found to be 100 and 89% respectively.

CONCLUSION

FDA staining is a simple and rapid tool for identifying viable MTB bacilli. Because of its excellent NPV and encouraging specificity, FDA staining is useful to identify patients with non-viable bacilli (FDA negative) among retreatment cases at diagnosis and patients on anti-tuberculosis treatment for both drug-sensitive and drug-resistant tuberculosis for follow up for the response of treatment.

Imaging the Actin Cytoskeleton in Live Budding Yeast Cells

Although budding yeast, Saccharomyces cerevisiae, is widely used as a model organism in biological research, studying cell biology in yeast was hindered due to its small size, rounded morphology, and cell wall. However, with improved techniques, researchers can acquire high-resolution images and carry out rapid multidimensional analysis of a yeast cell. As a result, imaging in yeast has emerged as an important tool to study cytoskeletal organization, function, and dynamics. This chapter describes techniques and approaches for visualizing the actin cytoskeleton in live yeast cells.

Imaging the Actin Cytoskeleton in Fixed Budding Yeast Cells

Budding yeast, Saccharomyces cerevisiae, is an appealing model organism to study the organization and function of the actin cytoskeleton. With the advent of techniques to perform high-resolution, multidimensional analysis of the yeast cell, imaging of yeast has emerged as an important tool for research on the cytoskeleton. This chapter describes techniques and approaches for visualizing the actin cytoskeleton in fixed yeast cells with wide-field and super-resolution fluorescence microscopy.

Evaluation of the vital viability and their application in fungal spores' disinfection with flow cytometry

More attention was focused on fungi contamination in drinking water. Most researches about the inactivation of fungal spores has been conducted on disinfection efficiency and the leakage of intracellular substances. However, the specific structural damage of fungal spores treated by different disinfectants is poorly studied. In this study, the viability assessment methods of esterase activities and intracellular reactive oxygen species (ROS) were optimized, and the effects of chlorine-based disinfectants on fungal spores were evaluated by flow cytometry (FCM) and plating. The optimal staining conditions for esterase activity detection were as follows: fungal spores (10⁶ cells/mL) were stained with 10 μM carboxyfluorescein diacetate and 50 mM ethylene diamine tetraacetic acid at 33 °C for 10 min (in dark). The optimal staining conditions for intracellular ROS detection were as follows: dihydroethidium (the final concentration of 2 μg/mL) was added into fungal suspensions (10⁶ cells/mL), and then samples were incubated at 35 °C for 20 min (in dark). The cell culturability, membrane integrity, esterase activities, and intracellular ROS were examined to reveal the structural damage of fungal spores and underlying inactivation mechanisms. Disinfectants would cause the loss of the cell viability via five main steps: altered the morphology of fungal spores; increased the intracellular ROS levels; decreased the culturability, esterase activities and membrane integrity, thus leading to the irreversible death. It is appropriate to assess the effects of disinfectants on fungal spores and investigate their inactivation mechanisms using FCM.

Minimally invasive procedures for the recognition and diagnosis of oral precancer and cancer

Oral cancer represents a blend of genetic and epigenetic instability. Many a times, oral cancer occurs in the background of oral potentially malignant disorders (OPMDs), which could be easily detected and diagnosed. Various diagnostic aids have been explored for early detection of oral cancer. Some of the minimally invasive (chair-side diagnostic) procedures such as vital staining and light-based systems are used widely in the clinical practice as well as in the hospital setting owing to their simple and easy operability. In addition, these chair-side diagnostic procedures offer relatively good sensitivity and specificity despite some of their limitations. These diagnostic tools could complement good clinical history and thorough examination of patients for early detection of oral precancer and cancer.

Visualization of Arbuscular Mycorrhizal Fungal Extraradical Hyphae and Spores Vitality and Activity

The hyphae and spores of arbuscular mycorrhizal (AM) fungi represent an essential component in the extraradical zone due to their role in nutrients and water uptake and as propagules that allow the perpetuation of the AM symbiosis over time, respectively. However, the attention of scientific literature is usually more focused on root colonization than on the study of the extraradical components of AM fungi, especially their vital, active, or functional fractions. This chapter presents some easy-to-use alternatives for staining vital, active, or functional structures of AM fungi for their subsequent microscopic visualization, such as the application of enzyme-based stains, NADPH formation, and also nucleus staining. Some modified methods for the extraction of mycelium from the soil are also presented.

Live-cell imaging of mitochondrial motility and interactions in Drosophila neurons and yeast

Mitochondria are highly dynamic organelles that undergo directed movement and anchorage, which in turn are critical for calcium buffering and energy mobilization at specific regions within cells or at sites of contact with other organelles. Physical and functional interactions between mitochondria and other organelles also impact processes, including phospholipid biogenesis and calcium homeostasis. Indeed, mitochondrial motility, localization, and interaction with other organelles are compromised in many neurodegenerative diseases. Here, we describe methods to visualize and carry out quantitative analysis of mitochondrial movement in two genetically-manipulatable, widely-used model systems: Drosophila neurons and the budding yeast, Saccharomyces cerevisiae. We also describe approaches for multi-color imaging in living yeast cells that may be used to visualize colocalization of proteins within mitochondria, as well as interactions of mitochondria with other organelles.

MICAN, a new fluorophore for vital and non-vital staining of human cells

Fluorescence time-lapse microscopy is in connection with the invasive properties of fluorochrome applied, and with the toxicity of the excitation energy and wavelength of the dye itself. Experiments with the newly synthesized fluorescent dye 1-N-methylamino-5-isocyanonaphthalene (MICAN) served to test its cytotoxicity on human HaCaT keratinocyte cell cultures. Experiments related to staining capability were performed with paraformaldehyde (PFA) fixed cells and observed with fluorescence microscope. It was assumed that the fluorophore 1-amino-5-isocyanonaphthalene (ICAN) and especially its N-methylamino derivative MICAN, containing condensed aromatic rings could serve as a nonselective fluorescent dye capable to stain cellular structures of fixed, living, damaged and dead cells. This notion was confirmed by the MICAN staining of cytoplasmic proteins primarily rough endoplasmic reticulum (RER), smooth endoplasmic reticulum (SEM) and less efficiently nuclear proteins suggesting the involvement of staining of subcellular structures involved in protein synthesis. MICAN was not only well tolerated by living cells but turned out to be a strong heterochromatin and RER staining agent. This led to the development of a MICAN staining protocol for native and living samples. Relative to other fluorescent dyes, MICAN is not only useful but also cost-effective. Toxicology tests were performed using 30, 10, 5, 0.5 μg/ml MICAN concentrations. Time-lapse videomicroscopy at near-infrared (NIR) illumination has been used for the examination of MICAN effect on cell division. It was found that MICAN as a vital stain had no significant harmful effect on HaCaT cells. MICAN turned out to be a non-toxic, highly quantum-efficient vital stain with minimal, or no photobleaching, and can be applied to co-stain with propidium-iodide due the strong spectral separation.

Development of macaque secondary follicles exposed to neutral red prior to 3-dimensional culture

PURPOSE

Neutral red (NR) may assist identification of preantral follicles in pieces of cortical tissue prior to cryopreservation in cancer patients requesting fertility preservation. This study is the first to analyze this effect by follicle growth rate after long-term culture in primates.

METHODS

Ovarian cortex was obtained from adult rhesus macaques, was cut into fragments, and was incubated with NR. Secondary follicles were readily visualized following NR staining and then were encapsulated into alginate beads and cultured individually for 4 weeks in αMEM media supplemented with 10 ng/ml FSH at 5% O2.

RESULTS

The survival rates of secondary follicles during culture were similar between those derived from control tissue (71 ± 13%) and those treated with NR (68 ± 9%). The proportion of surviving follicles that formed an antrum were also similar in both groups (70 ± 17% control; 48 ± 24% NR-treated). Follicle diameters were not different between control follicles (184 ± 5μm) and those stained with NR (181 ± 7 μm) on the day of isolation. The percentages of surviving follicles within three cohorts based on their diameters at week 4 of culture were similar between the control group and NR-stained tissue group, fast-grow follicles (24 ± 6% vs. 13 ± 10%), slow-grow follicles (66 ± 5% vs. 60 ± 9%), or no-grow (10 ± 9% vs. 27 ± 6%), respectively. There were no differences in follicle diameters between groups during the culture period. Pre-exposure of secondary follicles to NR diminished their capacity to produce both estradiol and androstenedione by week 4 of culture, when follicles are exhibiting an antrum. Inhibitory effects of NR on steroid production by slow-grow follicles was less pronounced.

CONCLUSIONS

NR does not affect secondary follicle survival, growth, and antrum formation during long-term culture, but steroid hormone production by fast-grow follicles is compromised. NR can be used as a non-invasive tool for in situ identification of viable secondary follicles in ovarian cortex before tissue cryopreservation without affecting follicle survival and growth in vitro. Whether maturation or developmental competence of oocytes derived from antral follicles in 3D culture that were previously isolated from NR-stained tissue is normal or compromised remains to be determined. Likewise, the functional consequences of pre-exposure to NR prior to ovarian cortical tissue cryopreservation and transplantation are unknown.

Role of Toluidine Blue Staining in Suspicious Lesions of Oral Cavity and Oropharynx

Oral cancer; the sixth most common malignancy in the world has one of the lowest 5 year survival rates. This can be attributed mainly to the delay in diagnosis. The purpose of this study was to evaluate the efficacy of vital staining with toluidine blue dye as an adjunct to standard clinical examination to facilitate early detection of malignant lesions of oral cavity and oropharynx. A hospital based diagnostic test accuracy study was carried out on 55 subjects with oral mucosal disorders that included clinically suspicious premalignant or malignant lesions, in the Department of ENT, Academy of Medical Sciences, Pariyaram, Kannur, Kerala over a period of 2 years. All lesions were subjected to detailed clinical examination and toluidine blue staining; and dye retention was recorded with photographs. The results of staining were compared with findings on histopathological examination. The Sensitivity and specificity of toluidine blue test for the detection of malignancy was 92.6 and 67.9% respectively; and the overall diagnostic accuracy was 80%. The result was highly significant with a 'p value' <0.001. The results indicate that toluidine blue staining is a simple, non-invasive technique which can be a valuable adjunct in the diagnostic process of oral and oropharyngeal cancers.

Evaluation of a vital staining protocol with 2,3,5-triphenyltetrazolium chloride for cancellous bone in a sheep model

Decision making on the optimal surgical treatment of fractures often is hampered by the lack of a method for direct assessment of bone vitality. In various contexts, for example to determine the extents of cerebral insults or of myocardial infarctions in experimental studies, tetrazolium based staining procedures of vital cells are widely used. Here, we set out to test the applicability of tetrazolium based staining on bone samples. 8 brains and 26 femoral heads from sheep were used to prepare tissue slices, which were stained with 2,3,5-triphenyltetrazolium chloride (TTC) at various times (1 to 12h) after explantation. Staining of tissue slices was quantified by densitometric image analysis. Spectrophotometry was used for quantification in cultured cells. TTC-staining of tissue slices indicated detectability of vital cells in slices from both tissues up to 4h after explantation. Staining intensity at later time-points was indistinguishable from the staining of untreated samples or sodium azide treated (necrotic cells) controls. We provide experimental evidence that the choice of the optimal surgical approach for the treatment of fractures involving cancellous bone could be aided by a simple staining procedure for vital bone. However, the described procedure depends on the availability of bone specimens (slices). Therefore, search for an improved stain directly applicable to the bone surface is needed.

Live-Cell Imaging of Mitochondria and the Actin Cytoskeleton in Budding Yeast

Maintenance and regulation of proper mitochondrial dynamics and functions are necessary for cellular homeostasis. Numerous diseases, including neurodegeneration and muscle myopathies, and overall cellular aging are marked by declining mitochondrial function and subsequent loss of multiple other cellular functions. For these reasons, optimized protocols are needed for visualization and quantification of mitochondria and their function and fitness. In budding yeast, mitochondria are intimately associated with the actin cytoskeleton and utilize actin for their movement and inheritance. This chapter describes optimal approaches for labeling mitochondria and the actin cytoskeleton in living budding yeast cells, for imaging the labeled cells, and for analyzing the resulting images.

Imaging of the Actin Cytoskeleton and Mitochondria in Fixed Budding Yeast Cells

The budding yeast Saccharomyces cerevisiae is widely used as a model system to study the organization and function of the cytoskeleton. In the past, its small size, rounded shape, and rigid cell wall created obstacles to explore the cell biology of this model eukaryote. It is now possible to acquire and analyze high-resolution and super-resolution multidimensional images of the yeast cell. As a result, imaging of yeast has emerged as an important tool in eukaryotic cell biology. This chapter describes labeling methods and optical approaches for visualizing the cytoskeleton and interactions of the actin cytoskeleton with mitochondria in fixed yeast cells using wide-field and super-resolution fluorescence microscopy.