Journal of Histotechnology最新文献

Investigating the function of delicate mammalian eyes often requires chemical fixation, histological sectioning, immunohistochemistry (IHC) and in situ hybridization (ISH). One of the long-standing challenges in the ocular histology field is the limited success of maintaining intact morphology via cryo- or paraffin procedures. Although our latest protocol significantly improved the morphology of mouse eyeball sections, the window technique is time-consuming and requires extensive practice to avoid damage while making windows. In this study, we present a novel glyoxal fixative that is suitable for a freeze-substitution approach to improve both morphology and molecular target preservation of mouse eyes. The method prevents morphology distortion in all tested eyeballs. Therefore, it suits a variety of research needs from morphological examination to investigation of single-molecule RNA expression, using hematoxylin and eosin (H&E) stain, IHC, and ISH assays on either frozen (cryo) or paraffin-infiltrated tissue sections. In addition, this method can be easily performed in many histology laboratories.

Traumatic, inherited, and age-related degenerative diseases of the retina, such as retinal detachment, retinitis pigmentosa, and age-related macular degeneration, are characterized by the irreversible loss of retinal neurons. While current treatments aim to prevent neuronal degeneration, there are no available treatments to restore neurons after loss. Cultured murine neuroretinal tissue explants model retinal injury and offer a high throughput approach to identify experimental interventions capable of regenerating neurons. Formalin-fixed paraffin-embedded (FFPE) preparations of murine neuroretinal explants can be used to identify cells throughout the retinal layers to provide information on proliferation and activity following exposure to therapeutics. However, retinal explants are friable, particularly after ex vivo culture, sample handling and FFPE processing steps can result in tissue loss and damage. Friability also prohibits bisecting samples post-culture to display more than one region of interest for analysis. We developed a sample handling and embedding technique for cultured murine neuroretinal explants using Histogel^TM in combination with a post-processing trimming step that eliminates tissue loss, increases cross-sectional retinal representation, and captures proximal and central retina on one slide to facilitate analysis of explants subjected to neurotrophic compounds.

Collection, preservation, and shipment of histological specimens in low-resource settings is challenging. We present a novel method that achieved excellent preservation of placental specimens from rural Mali by using formalin fixation, ethanol dehydration, and long-term storage in a solar-powered freezer. Sample preservation success was 92%, permitting evaluation of current and past malaria infection, anemia, placental maturity, and inflammation. Using RNAscope® hybridization we were able to visualize cell-specific gene expression patterns in the formalin-fixed paraffin-embedded (FFPE) specimens. Additionally, our method entailed mirrored sampling from the two cut faces of a cotyledon, one for the FFPE workflows and the other for storage in RNAlater™ and RNA-seq.

This article discusses current available resources with respect to regulatory agencies including the Occupational Safety and Health Administration (OSHA) for determining the requirements placed upon laboratories for handling of hazardous materials. The focus is specific to the histology laboratory and xylene use, and includes a literature review, admixed with historical reference points. Procedures and tasks in the histology laboratory are highlighted in relation to their connection to the quality of the work environment with an emphasis on air quality. Recommendations are provided for maintaining an appropriate work environment for the prevention of potential adverse health effects. The gap within the OSHA Laboratory Standard, i.e. a lack of explanatory language, leaves much open to interpretation regarding fume hood usage with volatile hazardous chemicals. As a result, both the level of safety training and the awareness of good laboratory practices (GLP) for handling volatile hazardous reagents such as xylene can become compromised.

Aim To investigate possible differences in serum glucose and sodium and potassium concentrations with respect to age, gender and severity of diabetic ketoacidosis. Methods Medical records from 1 January 2017 to 31 December 2019 were reviewed and patients with the diagnosis of diabetic ketoacidosis were selected. Results The study included 52 patients. Glucose concentration was significantly higher in the age group of 25-44 and >65 years compared to the group of 18-24 years (p=0.02). Sodium concentration was significantly higher in the age group 18-24 and >65 years compared to groups 25-44 and 45-65 years (p=0.002). Females had significantly higher sodium concentration than males (p=0.002). Potassium concentration was significantly higher in the age group 25-44 years compared to other groups (p=0.01). Males had significantly higher potassium concentration (p =0.01). Conclusion This study showed that significant differences exist in electrolyte concentration between specific age groups, male and female gender as well as DKA severity. Knowing these differences could help clinicians to promptly recognize and treat electrolyte derangements, leading to better outcome of patients with DKA.

Cryopreserving tissues for histology requires the use of coolants to buffer the sample from liquid nitrogen (LN₂) and to control the rate of temperature decline. Several coolants sharing similar physical characteristics are available on the market; however, commonly used coolants are variably flammable and/or toxic and pose risks to personnel and facilities. The purpose of this study was to compare the performance of three commercially available coolants: hexane, 2-methylbutane (2 M), and 1-methoxyheptafluoropropane (N7000). Fresh mouse tissues were frozen by each method, for their ability to preserve microscopic architecture and to protect RNA from degradation were evaluated and compared to tissue characteristics obtained by direct immersion in LN₂. Our results show that for most tissues, the N7000 freezing coolant provides equal or improved preservation of microscopic architecture. While snap-freezing tissues in LN₂ provides superior RNA protection, no significant differences in RNA quality were seen between tissues frozen in hexane, 2 M, and N7000.