Strategies for selecting and managing equipment in a light microscopy facility

Light microscopy facilities vary in the number of imaging systems and the scope of technologies they support. Each facility must craft an identity through the selection of equipment and development of staff in order to serve the needs of its local research environment. The process of crafting a light microscopy facility can be compared to curation of an art exhibition: great care should be given to the selection and placement of each object in order to make a coherent statement. Lay Description: Light microscopy facilities vary in the number of imaging systems and the scope of technologies they support. Each facility must develop an identity through the selection of equipment and development of staff in order to serve the needs of its local research environment. The process of crafting a light microscopy facility can be compared to curation of an art exhibition: great care should be given to the selection and placement of each object in order to make a coherent statement.

'Branded' microscopy core facilities - Mutually beneficial partnerships between academia and industry

Core facilities are research laboratories staffed by professional scientists who can provide access, training, support, and maintenance for the utilisation of highly specialised instrumentation. Microscopy core facilities support researchers working in many areas with wide ranging imaging needs. The companies that manufacture, sell, and service advanced microscopy instrumentation often develop strong and mutually beneficial relationships with their customers, which sometimes lead to contractual agreements with academic research institutions, resulting in so-called 'branded' core facilities. These academic-industrial partnerships can have significant benefits for both parties and ultimately can serve to improve the scientific resources available to the core facility user base. The article will describe these types of arrangements and specifically highlight aspects of these agreements that can benefit each partner in addition to some specific challenges that can arise with 'branded' core facilities.

Improving light microscopy training routines with evidence-based education

The low reproducibility of scientific data published in articles has recently become a cause of concern in many scientific fields. Data involving light microscopy is no exception. The low awareness of researchers of the technologies they use in their research has been identified as one of the main causes of the problem. Potential solutions have hinted at the need to improve technological and methodological education within research. Despite the pivotal role of microscopy core facilities in the education of researchers being well documented, facility staff (FS) often learn their trade on the job, without receiving themselves any structured education about the technology they teach others to use. Additionally, despite endorsing an important role at the highest level of education, most FS never receive any training in pedagogy, the field of research on teaching and learning methods. In this article, we argue that the low level of awareness that researchers have of microscopy stems from a knowledge gap formed between them and microscopy FS during training routines. On the one hand, FS consider that their teaching task is to explain what is needed to produce reliable data. On the other, despite understanding what is being taught, researchers fail to learn the most challenging aspects of microscopy, those involving their judgement and reasoning. We suggest that the misunderstanding between FS and researchers is due to FS not being educated in pedagogy and thus often confusing understanding and learning. To bridge this knowledge gap and improve the quality of the microscopy education available to researchers, we propose a paradigm shift where training staff at technological core facilities be acknowledged as full-fledged teachers and offered structured education not only in the technology they teach but also in pedagogy. We then suggest that training routines at facilities be upgraded to follow the principles of the Constructive Alignment pedagogical method. We give an example of how this can be applied to existing microscopy training routines. We also describe a model to define where the responsibility of FS in training researchers begins and ends. This involves a major structural change where university staff involved in teaching research technologies themselves receive appropriate education. For this to be achieved, we advocate that funding agencies, universities, microscopy and core facility organisations mobilise resources of time and funding. Such changes may involve funding the creation and development of 'Train-the-trainer' type of courses and giving incentives for FS to upgrade their technological and pedagogical knowledge, for example by including them in career paths. We believe that this paradigm shift is necessary to improve the level of microscopy education and ultimately the reproducibility of published data.

Fluorescence microscopic investigation of PCE superplasticiser adsorption in calcined clay blended cement

Global efforts to minimise carbon dioxide emissions are also leading to attempts to use calcined clays (CC) as a partial substitute for cement in concrete. While the hydration mechanism of such CC blended cements is now well understood, the range of effective admixtures like polycarboxylate ethers (PCE) is limited. There are PCE types that promise relatively high effectiveness, but the mechanisms of action are not yet sufficiently understood. For a detailed understanding of the adsorption of such PCEs, spatially resolved studies of the binder were performed using a combination of fluorescence and scanning electron microscopy. In a comparison of two superplasticisers, the investigations have shown different sites of preferred adsorption in a CC blended system and the results can be correlated with flow tests and setting behaviour. The investigations have shown that a certain PCE type has a higher adsorption on CC and other components of a blended system in comparison to other types.

Prostatic morphological changes throughout life: Cytochemistry as a tool to reveal tissue aging markers

The prostate undergoes normal or pathological morphological changes throughout life. An understanding of these changes is fundamental for the comprehension of aging-related pathological processes such as benign prostatic hyperplasia (BPH) and cancer. In the present study, we show some of these morphological changes, as well as histochemical techniques like Weigert's resorcin-fuchsin method, Picrosirius Red, and Gömöri's reticulin for use as tools in the study of prostate tissue under light microscopy. For this purpose, prostates of the Mongolian gerbil (n = 9), an experimental model that develops BPH spontaneously, were analyzed at three life stages: young (1 month old), adult (3 months old), and old (15 months old). The results showed that fibrillar components such as collagen, and reticular and elastic fibers, change throughout life. In young animals, the prostate has cuboidal epithelium surrounded by thin layers of smooth muscle, continuous collagen fibers, winding reticular fibers, and sporadic elastic fibers. With adulthood, the epithelium becomes columnar, encircled by compacted muscle cells among slender collagen fibers, elongated reticular fibers, and linear elastic fibers. In aging individuals, the prostate's epithelium stratifies, surrounded by thick muscle layers among dense collagen fibers, disordered reticular fibers, and elastic fibers in different planes. We also identified a few accumulations of lipid droplets and lipofuscin granules in adult animals and high accumulation in old animals evidenced by Oil red O and Gömöri-Halmi techniques, respectively. The histochemical techniques presented here have been demonstrated to be useful and accessible tools in prostate studies. RESEARCH HIGHLIGHTS: Cytochemical techniques to study prostate morphology. The prostate changes with age.

New approaches for low phototoxicity imaging of living cells and tissues

Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to erroneous or inconclusive results. Recently, several reports have addressed this issue, but it is still underestimated by many researchers, even though it can lead to cell death. Phototoxicity can be reduced by appropriate microscopic techniques and carefully designed experiments. This review focuses on recent strategies to reduce phototoxicity in microscopic imaging of living cells and tissues. We describe digital image processing and new hardware solutions. We point out new modifications of microscopy methods and hope that this review will interest microscopy hardware engineers. Our aim is to underscore the challenges and potential solutions integral to the design of microscopy systems. Simultaneously, we intend to engage biologists, offering insight into the latest technological advancements in imaging that can enhance their understanding and practice.

Prostate-specific antigen: An unfamiliar protein in the human salivary glands

OBJECTIVES

The presence of prostate-specific antigen (PSA) in saliva and salivary glands has been reported. Nevertheless, its release pathway in these glands remains to be elucidated. Here, we showed PSA subcellular distribution focusing on its plausible route in human salivary parenchyma.

MATERIALS AND METHODS

Sections of parotid and submandibular glands were subjected to the immunohistochemical demonstration of PSA by the streptavidin-biotin method revealed by alkaline phosphatase. Moreover, ultrathin sections were collected on nickel grids and processed for immunocytochemical analysis, to visualize the intracellular distribution pattern of PSA through the observation by transmission electron microscopy.

RESULTS

By immunohistochemistry, in both parotid and submandibular glands PSA expression was detected in serous secretory acini and striated ducts. By immunocytochemistry, immunoreactivity was retrieved in the cytoplasmic compartment of acinar and ductal cells, often associated with small cytoplasmic vesicles. PSA labeling appeared also on rough endoplasmic reticulum and in the acini's lumen. A negligible PSA labeling appeared in most of the secretory granules of both glands.

CONCLUSIONS

Our findings clearly support that human parotid and submandibular glands are involved in PSA secretion. Moreover, based on the immunoreactivity pattern, its release in oral cavity would probably occur by minor regulated secretory or constitutive-like secretory pathways.

Macro- and micro-morphological comparison of the detailed structure of the oral cavity roof in two different feeding habits marine fishes: Pagrus pagrus and Boops boops

The feeding habits and habitats of fish influence the morphology of the oral cavity. This study used gross anatomy, light microscopy, and scanning electron microscopy, in addition to morphometric analysis, to investigate the anatomical characteristics of the oral cavity roof in Pagrus pagrus and Boops boops, which have different dietary habits. The oral cavity roof appeared U-shaped and divided into the palate and upper pharyngeal regions. The upper lip of P. pagrus was broad, while B. boops' upper lip was small and thin. Both species had a stratified squamous epithelium with an irregular shape and a folded surface. P. pagrus had a horseshoe-shaped upper velum with a high middle part, and its surface resembled sea waves with obvious mucous-secreting openings with cilia and many folds and grooves between them. B. boops's upper velum was thin and appeared as a triangle pouch with a pointed cranial apex. The palate in both species was narrow in the front and increased in width backward until it ended. The upper pharyngeal teeth in P. pagrus appeared as two patches, separated by a median longitudinal ridge and an anterior V-shape separator. Meanwhile, in B. boops, they appeared as a ball patch on both sides and a separator ridge in the middle. Because P. pagrus fed on harder structures than B. boops, their feeding habits were reflected in the structure of the oral cavity roof. P. pagrus, a carnivorous species, had several rows of sharp upper jaw and upper pharyngeal teeth, thick spinous tubercles on oblique transverse ridges, and massive mucous glands. On the other hand, B. boops, an omnivorous species, had only one row of upper jaw teeth, a few upper pharyngeal teeth scattered on two oval patches, and thin filaments on the oblique transverse ridges.

Developmental stages and episode-specific regulatory genes in andromonoecious melon flower development

BACKGROUND AND AIMS

Given the lack of specific studies on floral development in melon (Cucumis melo L.), we carried out an extensive study involving morphological and transcriptomic analyses to characterize floral development in this species.

METHODS

Using an andromonoecious line, we analysed the development of floral buds in male and hermaphrodite flowers with both light microscopy and scanning electron microscopy. Based on flower lengths, we established a correlation between the developmental stages and four main episodes of floral development and conducted an extensive RNA sequencing analysis of these episodes.

KEY RESULTS

We identified 12 stages of floral development, from the appearance of the floral meristems to anthesis. The main structural differences between male and hermaphrodite flowers appeared between stages 6 and 7; later stages of development leading to the formation of organs and structures in both types of flowers were also described. We analysed the gene expression patterns of the four episodes in flower development to find the genes that were specific to each given episode. Among others, we identified genes that defined the passage from one episode to the next according to the ABCDE model of floral development.

CONCLUSIONS

This work combines a detailed morphological analysis and a comprehensive transcriptomic study to enable characterization of the structural and molecular mechanisms that determine the floral development of an andromonoecious genotype in melon. Taken together, our results provide a first insight into gene regulation networks in melon floral development that are crucial for flowering and pollen formation, highlighting potential targets for genetic manipulation to improve crop yield of melon in the future.

Imaging plant cell walls using fluorescent stains: The beauty is in the details

Plants continuously face various environmental stressors throughout their lifetime. To be able to grow and adapt in different environments, they developed specialized tissues that allowed them to maintain a protected yet interconnected body. These tissues undergo specific primary and secondary cell wall modifications that are essential to ensure normal plant growth, adaptation and successful land colonization. The composition of cell walls can vary among different plant species, organs and tissues. The ability to remodel their cell walls is fundamental for plants to be able to cope with multiple biotic and abiotic stressors. A better understanding of the changes taking place in plant cell walls may help identify and develop new strategies as well as tools to enhance plants' survival under environmental stresses or prevent pathogen attack. Since the invention of microscopy, numerous imaging techniques have been developed to determine the composition and dynamics of plant cell walls during normal growth and in response to environmental stimuli. In this review, we discuss the main advances in imaging plant cell walls, with a particular focus on fluorescent stains for different cell wall components and their compatibility with tissue clearing techniques. Lay Description: Plants are continuously subjected to various environmental stresses during their lifespan. They evolved specialized tissues that thrive in different environments, enabling them to maintain a protected yet interconnected body. Such tissues undergo distinct primary and secondary cell wall alterations essential to normal plant growth, their adaptability and successful land colonization. Cell wall composition may differ among various plant species, organs and even tissues. To deal with various biotic and abiotic stresses, plants must have the capacity to remodel their cell walls. Gaining insight into changes that take place in plant cell walls will help identify and create novel tools and strategies to improve plants' ability to withstand environmental challenges. Multiple imaging techniques have been developed since the introduction of microscopy to analyse the composition and dynamics of plant cell walls during growth and in response to environmental changes. Advancements in plant tissue cleaning procedures and their compatibility with cell wall stains have significantly enhanced our ability to perform high-resolution cell wall imaging. At the same time, several factors influence the effectiveness of cleaning and staining plant specimens, as well as the time necessary for the process, including the specimen's size, thickness, tissue complexity and the presence of autofluorescence. In this review, we will discuss the major advances in imaging plant cell walls, with a particular emphasis on fluorescent stains for diverse cell wall components and their compatibility with tissue clearing techniques. We hope that this review will assist readers in selecting the most appropriate stain or combination of stains to highlight specific cell wall components of interest.

Comparative microscopic investigations of leaf epidermis in four Ajuga species from Korea

The genus Ajuga is widely distributed in temperate to subtropical regions, and four species are currently recognized in Korea (A. decumbens, A. multiflora, A. nipponensis, and A. spectabilis), but epidermal anatomical differences across these species have never been described. A comparative study of the leaf micromorphological characteristics of Korean Ajuga species was performed using light microscopy (LM) and scanning electron microscopy (SEM) to elucidate their taxonomic usefulness and to assess leaf micromorphological diversity. Considerable diversity in epidermal and stomatal anatomy was observed across Korean Ajuga species. Species had both hypostomatic or amphistomatic leaves, with anomocytic, anisocytic, diactyic, or actinocytic stomatal complexes. Guard cell length across species ranged from 17.66 ± 0.57 μm to 32.50 ± 2.38 μm and correlated with genome size. Abnormal stomata were frequently observed in three species (A. decumbens, A. multiflora, and A. nipponensis) but not in A. spectabilis. Three types of glandular trichomes were found: peltate in all species, short-stalked in all species, and long-stalked glandular trichomes in A. multiflora. Among the investigated leaf micromophological characters, trichome type, epidermal cell shape, and stomatal morphology were all taxonomically informative traits at a species level. RESEARCH HIGHLIGHTS: A comprehensive micromorphological description of the leaf surface is provided for Korean Ajuga species using scanning electron microscopic (SEM) and light microscopic (LM) analyses. The diverse range of stomatal development and the occurrence of polymorphic stomatal types are documented for the first time in Korean Ajuga species. The great diversity in stomatal and trichome morphology in Korean Ajuga species are taxonomically useful traits for species identification.

A comparative study on the antennae morphology and ultrastructure of three mud crab species of the genus Scylla from Setiu Wetlands, Terengganu, Malaysia

Crustaceans possess a range of sensory organs crucial in sensory perception, communication, and various ecological functions. Understanding morphological and functional differences in antennae among species could validate taxonomic differentiation and ecological adaptations. The antennae morphology and ultrastructure of mud crab species within the Scylla genus are poorly understood, and their role in ecological adaptation and species differentiation remains unexplored. This study aimed to describe and compare the morphology and ultrastructure of antennae in Scylla olivacea, Scylla tranquebarica, and Scylla paramamosain. Antennae were carefully excised from each crab and subjected to morphological, morphometric, and ultrastructural analysis. The study revealed that the antennae of Scylla species exhibit similar overall morphology, with a series of segments that tapered toward the upper end. All species possess non-branched single setae on the upper end of each segment. The number of antennae segments varied between species, with S. paramamosain having significantly more segments than S. olivacea. Additionally, the length and width of antenna segments differed among the species, with S. tranquebarica having a rougher antenna surface compared to S. olivacea and S. paramamosain. Our findings suggest that Scylla's antennae are distinct between species, especially in the number of segments and setae size. Such difference might be related to ecological adaptation. The role of antennae in sensory perception and social behavioral cues in mud crabs warrants further investigation. This study serves as a foundational reference for future research on the taxonomy, ecological adaptation, and sensory behaviors in the Scylla genus. RESEARCH HIGHLIGHTS: Variations and similarities in morphology and ultrastructure of three Scylla species can be found in the antennae. Scylla paramamosain had significantly higher number of segments than Scylla olivacea in morphology feature. The antennae surface of Scylla tranquebarica was rougher than that of S. olivacea and S. paramamosain. Antennae of three Scylla species possess non-branched single setae.

Myelin histology: a key tool in nervous system research

The myelin sheath is a lipoprotein-rich, multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers. Due to the complex structure and composition of myelin, various histological techniques have been developed over the centuries to evaluate myelin under normal, pathological or experimental conditions. Today, methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience research. In this review, we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures, from tissue fixation and processing techniques to the most used and practical myelin histological staining methods. Considering the lipoprotein nature of myelin, the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described, as well as the precise ultrastructural techniques.

Palynological investigation of some Euphorbia L. (Euphorbiaceae) taxa from Turkey using light and scanning electron microscopy

Euphorbia L., one of the largest genera of angiosperms, is represented by the subgenera Esula Pers. and Chamaesyce Raf. in Turkey. Subg. Esula is confined mainly to Eurasia, especially in the Mediterranean region, and has not yet been studied in detail palynologically. In the present study, the pollen morphology of 14 taxa belonging to the sections Helioscopia Dumort., Myrsiniteae (Boiss.) Lojac., Pithyusa (Raf.) Lázaro, Patellares (Prokh.) Frajman, Exiguae (Geltman) Riina & Molero, Paralias Dumort., and Esula (Pers) Dumort. of Euphorbia L. subg. Esula Pers. from European Turkey was examined using light and scanning electron microscopy. The pollen grains were found to be trizonocolporate, isopolar, radially symmetrical, medium in size, and oblate spheroidal and suboblate in shape. Ectoapertures were elongated colpi with distinct margins, widened at the equatorial region, and tapered at the ends; margo was present in all samples as a smooth exine surrounding the colpi. The endoapertures were lolongate pori with distinct costae. The exine was tectate-perforate. The ornamentation was perforate, microreticulate-perforate, microreticulate-perforate with rugulose, or microreticulate-perforate with a heterobrochate pattern. The sexine was generally thicker than the nexine, with some exceptions where the sexine was almost equal to the nexine. Pollen size, pollen shape, and exine ornamentation have taxonomic importance in distinguishing species; however, these features do not provide strong support for grouping or delimitating the taxa at the sectional level. RESEARCH HIGHLIGHTS: Pollen size, pollen shape, and exine ornamentation are taxonomically important for distinguishing Euphorbia species. The exine ornamentation was observed to be perforate, microreticulate-perforate, microreticulate-perforate with a rugulose pattern, and microreticulate-perforate with a heterobrochate pattern.

[Morphological features of vasoproliferative tumor of the retina]

Vasoproliferative retinal tumor (VPT) is a term proposed by ophthalmologists in relation to the totality of manifestations of an intraocular volumetric process with involvement of the inner lining of the eye, an integral part of which is the active growth of blood vessels. The available literature data on the morphology of this process are very contradictory and ambiguous. The article presents two clinical cases of vasoproliferative retinal tumor with own illustration of morphological studies.

Extracellular traps are evident in Romanowsky-stained smears of bronchoalveolar lavage from children with non-cystic fibrosis bronchiectasis

BACKGROUND AND OBJECTIVE

The importance of extracellular traps (ETs) in chronic respiratory conditions is increasingly recognized but their role in paediatric bronchiectasis is poorly understood. The specialized techniques currently required to study ETs preclude routine clinical use. A simple and cost-effective ETs detection method is needed to support diagnostic applications. We aimed to determine whether ETs could be detected using light microscopy-based assessment of Romanowsky-stained bronchoalveolar lavage (BAL) slides from children with bronchiectasis, and whether the ETs cellular origin could be determined.

METHODS

Archived Romanowsky-stained BAL slides from a cross-sectional study of children with bronchiectasis were examined for ETs using light microscopy. The cellular origin of individual ETs was determined based on morphology and physical contact with surrounding cell(s).

RESULTS

ETs were observed in 78.7% (70/89) of BAL slides with neutrophil (NETs), macrophage (METs), eosinophil (EETs) and lymphocyte (LETs) ETs observed in 32.6%, 51.7%, 4.5% and 9%, respectively. ETs of indeterminate cellular origin were present in 59.6% of slides. Identifiable and indeterminate ETs were co-detected in 43.8% of slides.

CONCLUSION

BAL from children with bronchiectasis commonly contains multiple ET types that are detectable using Romanowsky-stained slides. While specialist techniques remain necessary to determining the cellular origin of all ETs, screening of Romanowsky-stained slides presents a cost-effective method that is well-suited to diagnostic settings. Our findings support further research to determine whether ETs can be used to define respiratory endotypes and to understand whether ETs-specific therapies may be required to resolve airway inflammation among children with bronchiectasis.

A Novel Monochromatic Light to Detect Target Specimens Within Endoscopic Ultrasonography-guided Fine-needle Aspiration Biopsy Samples

BACKGROUND/AIM

Endoscopic ultrasonography (EUS)-guided fine-needle aspiration biopsy (EUS-FNB) enhances the diagnostic capabilities of EUS by providing additional pathological samples. However, detecting the target specimens within the collected samples can be challenging. The aim of this study was to determine the optimal wavelength of light for detection of target specimens within EUS-FNB samples in an animal experiment.

MATERIALS AND METHODS

EUS-FNB pancreatic tissue samples were collected from a male beagle (weight, 10 kg), and the samples were illuminated with monochromatic light ranging from 430 to 700 nm in 5-nm intervals. The intensities of the target specimen and blood samples were analyzed using the densitometry of the images obtained through irradiation.

RESULTS

We found that transmitted monochromatic light of 605 nm most vividly enhanced the contrast between the target specimens and blood in the samples in the impression of appearance.

CONCLUSION

Thus, microscopical observations under transmitted light of 605 nm are optimal for target tissue identification within EUS-FNB samples.

The Value of Micro-CT in the Diagnosis of Lung Carcinoma: A Radio-Histopathological Perspective

Micro-computed tomography (micro-CT) is a relatively new imaging modality and the three-dimensional (3D) images obtained via micro-CT allow researchers to collect both quantitative and qualitative information on various types of samples. Micro-CT could potentially be used to examine human diseases and several studies have been published on this topic in the last decade. In this study, the potential uses of micro-CT in understanding and evaluating lung carcinoma and the relevant studies conducted on lung and other tumors are summarized. Currently, the resolution of benchtop laboratory micro-CT units has not reached the levels that can be obtained with light microscopy, and it is not possible to detect the histopathological features (e.g., tumor type, adenocarcinoma pattern, spread through air spaces) required for lung cancer management. However, its ability to provide 3D images in any plane of section, without disturbing the integrity of the specimen, suggests that it can be used as an auxiliary technique, especially in surgical margin examination, the evaluation of tumor invasion in the entire specimen, and calculation of primary and metastatic tumor volume. Along with future developments in micro-CT technology, it can be expected that the image resolution will gradually improve, the examination time will decrease, and the relevant software will be more user friendly. As a result of these developments, micro-CT may enter pathology laboratories as an auxiliary method in the pathological evaluation of lung tumors. However, the safety, performance, and cost effectiveness of micro-CT in the areas of possible clinical application should be investigated. If micro-CT passes all these tests, it may lead to the convergence of radiology and pathology applications performed independently in separate units today, and the birth of a new type of diagnostician who has equal knowledge of the histological and radiological features of tumors.

Differences and similarities in selenium biopathways in Astragalus, Neptunia (Fabaceae) and Stanleya (Brassicaceae) hyperaccumulators

BACKGROUND AND AIMS

Selenium hyperaccumulator species are of primary interest for studying the evolution of hyperaccumulation and for use in biofortification because selenium is an essential element in human nutrition. In this study, we aimed to determine whether the distributions of selenium in the three most studied hyperaccumulating taxa (Astragalus bisulcatus, Stanleya pinnata and Neptunia amplexicaulis) are similar or contrasting, in order to infer the underlying physiological mechanisms.

METHODS

This study used synchrotron-based micro-X-ray fluorescence (µXRF) techniques to visualize the distribution of selenium and other elements in fresh hydrated plant tissues of A. racemosus, S. pinnata and N. amplexicaulis.

KEY RESULTS

Selenium distribution differed widely in the three species: in the leaves of A. racemosus and N. amplexicaulis selenium was mainly concentrated in the pulvini, whereas in S. pinnata it was primarilylocalized in the leaf margins. In the roots and stems of all three species, selenium was absent in xylem cells, whereas it was particularly concentrated in the pith rays of S. pinnata and in the phloem cells of A. racemosus and N. amplexicaulis.

CONCLUSIONS

This study shows that Astragalus, Stanleya and Neptunia have different selenium-handling physiologies, with different mechanisms for translocation and storage of excess selenium. Important dissimilarities among the three analysed species suggest that selenium hyperaccumulation has probably evolved multiple times over under similar environmental pressures in the US and Australia.

Lead Exposure Assessment and Its Impact on the Structural Organization and Morphological Peculiarities of Rat Ovaries

Lead is known to be highly toxic to humans, causing various disorders infetal development. An experiment was conducted to examine the effects of lead acetate on the structural organization of female rat ovaries. The study involved 40 non-linear female rats divided into four groups: a control group, a low-dose group, a moderate-dose group, and a high-dose group. The rats were given lead acetate solutions in varying doses for 30 days, and their ovarian tissue was examined using light microscopy.The results showed that increasing doses of lead acetate led to morphological changes in the cortex and medulla of the rat ovaries. The changes were characterized by a decrease in ovarian mass, alterations in the thickness of the tunica albuginea (protein envelope), and a reduction in the number of follicles. Light microscopy revealed that exposure to lead acetate resulted in a significant decrease in the number of follicles in all experimental groups, with the high-dose group experiencing the most significant decrease.These findings suggest that lead acetate has a dose-dependent negative impact on the morphology and function of female rat ovaries. Further studies are needed to investigate the potential impact of lead on human ovarian tissue.

Removal and identification of a subconjunctival parasite by light and scanning electron microscopy

Background

Ophthalmic dirofilariasis is an uncommon zoonotic parasitic infection caused by species of Dirofilaria, a dog tapeworm that is transmitted to human by mosquitoes. Man is a dead-end host for the parasite. Ophthalmic involvement is rare and includes periorbital, subconjunctival, subtenon, and intra-ocular involvement. We report the removal of a subconjunctival worm and identification by light microscopy (LM) and scanning electron microscopy (SEM).

Purpose

: A 62-year-old female presented with complaints of redness, discharge, and foreign body sensation with difficulty in opening eyes in the left eye for the last 3 days. The patient is a non-vegetarian. On examination, her best corrected visual acuity in both eyes was 20/20. On slit lamp examination, there was a long, thin, round, coiled white subconjunctival live worm in the left eye superiorly. The rest of anterior segment evaluation, intra-ocular pressure, and fundus was normal in both eyes. The parasite was removed under local anesthesia from subconjunctival space [Video]. External surface morphology under LM revealed fine transverse cuticular striations with tapered cephalic and caudal ends. Uterus was long and coiled with indistinguishable masses inside. The finding was also confirmed by SEM.

Synopsis

A subconjuctival parasite was removed and identified as Dirofilaria repens by characteristic LM and SEM findings.

Highlight

Dirofilaria species may lodge in many tissues of human bodies including eye and adnexa. Dirofilaria is a natural parasite of carnivorous animals, mostly dogs, cats, and foxes.[1] The most common mode of transmission to human is usually by bite of mosquitoes like Culex and Aedes, which are considered as vectors, and it is often thought that parasitemia is because of accidental conduction.[1] Simple surgical removal of the worm is curative. After removal, the worm should be visualized directly under LM. All the internal structures of the transparent worm could be seen and compared with those under SEM.

Macroscopic and microscopic comparison of pecten oculi in different avian species

The current study aims to present differences between the pecten oculi of different avian species through morphologic, macroscopic, light, and electron microscopic examinations. The study is a comprehensive research on seven avian species (sparrowhawk, hawk, magpie, swan, heron, pheasant, duck). The right eyes of the animals utilized in the study were removed for light microscopic examination, whereas their left eyes were removed for electron microscopic and macroscopic examinations. Morphometric analyses, as well as stereo and light microscopic measurements, were carried out on the pecten oculi of the animals. Given all these data, it was determined that the height of the pecten oculi did not differ among the species in the study; however, the pecten oculi were larger in birds with the highest value compared to the other species in the macroscopic measurements. Also, the pecten oculi vessels were larger, and the number of melanocytes was higher in keen eyesight, raptor, and migratory birds with large bulbus oculi. All these data suggest that the pecten oculi not only supplies nutrient to the retina but also contributes to sharp vision during migration and hunting, UV absorption from sunlight, as well as preservation of intraocular equilibrium.

Changes in the Ultrastructure of Staphylococcus aureus Cells Make It Possible to Identify and Analyze the Injuring Effects of Ciprofloxacin, Polycationic Amphiphile and Their Hybrid

The purposeful development of synthetic antibacterial compounds requires an understanding of the relationship between effects of compounds and their chemical structure. This knowledge can be obtained by studying changes in bacteria ultrastructure under the action of antibacterial compounds of a certain chemical structure. Our study was aimed at examination of ultrastructural changes in S. aureus cells caused by polycationic amphiphile based on 1,4‒diazabicyclo[2.2.2]octane (DL412), ciprofloxacin and their hybrid (DL5Cip6); the samples were incubated for 15 and 45 min. DL412 first directly interacted with bacterial cell wall, damaging it, then penetrated into the cell and disrupted cytoplasm. Ciprofloxacin penetrated into cell without visually damaging the cell wall, but altered the cell membrane and cytoplasm, and inhibited the division of bacteria. The ultrastructural characteristics of S. aureus cells damaged by the hybrid clearly differed from those under ciprofloxacin or DL412 action. Signs associated with ciprofloxacin predominated in cell damage patterns from the hybrid. We studied the effect of ciprofloxacin, DL412 and their hybrid on S. aureus biofilm morphology using paraffin sections. Clear differences in compound effects on S. aureus biofilm (45 min incubation) were observed. The results obtained allow us to recommend this simple and cheap approach for the initial assessment of antibiofilm properties of synthesized compounds.

Anatomical and histochemical characterization of some highly medicinal plants as a tool for quality control

Medicinal plants are richest source of chemical compounds that can be used to evolve novel drugs. According to World Health Organization (WHO), in developing countries more than 3.5 billion people relay on herbal drugs for their primary health care. In the present study, an attempt was carried out to authenticate some selected medicinal plants (Fagonia cretica L., Peganum harmala L., Tribulus terrestris L., Chrozophora tinctoria L. Raf. and Ricinus communis L.) from family Zygophyllaceae and Euphorbiaceae using light and scanning electron macroscopic techniques. Macroscopic evaluation and comparative anatomy (Light Microscopy) of the root and fruits revealed great diversity in macro and microscopic features. Scanning electron microscopy (SEM) of root powder showed non-glandular trichomes, stellate trichomes, parenchyma cells and vessels. Fruits SEM exhibited non-glandular trichomes, glandular trichomes, stellate trichomes, peltate trichomes and mesocarp cells. Both macroscopic and microscopic evaluation plays a crucial role in the correct substantiation and validation of novel sources. These findings can serve as an essential source of information to accomplish the authenticity and to appraise the quality and purity of the herbal drugs in accordance to WHO guidelines. These parameters can be used to distinguish the selected plants from their commonly used adulterants. RESEARCH HIGHLIGHTS: In the current work, five plants (Fagonia cretica L., Peganum harmala L., Tribulus terrestris L., Chrozophora tinctoria L. Raf. and Ricinus communis L.) from Zygophyllaceae and Euphorbiaceae were investigated for macroscopy and microscopy (LM & SEM) for the first time. Macroscopic and microscopic evaluation disclosed great diversity in morphology and histology. Microscopy is the backbone of standardization process. Current study helped in correct identification and quality assurance of the plant materials. Their statistical investigation may possess great potency for plant taxonomists to further appraise the vegetative growth and tissue development which is requisite especially for fruit to enhance the yield of herbal drugs and their formulation. Further molecular studies, compounds isolation and characterization are required to deepen the knowledge of these herbal drugs.

Immunoelectron microscopy findings in a patient with C3 glomerulonephritis

We performed a kidney biopsy in a 36-year-old man to evaluate microscopic hematuria and proteinuria. Light microscopy showed increased mesangial matrix and partial swelling of the glomerular basement membrane (GBM), and immunofluorescence showed positive staining only for C3. Immunoelectron microscopy showed that gold particle-labeled C3 was localized in the electron-dense and moderately electron-dense deposits shown by electron microscopy in the mesangium, the thickened GBM near the paramesangium, and the thickened distal portion of the GBM but was not localized in the non-thickened GBM. Gold-labeled immunoglobulin G, κ, and λ were not seen. C3 glomerulonephritis was more evident in gold-labeled electron microscopy, which further clarified the localization of C3 deposition.

Light and scanning electron microscopic characterization of the Egyptian buffalo hair in relation to age with analysis by SEM-EDX

The purpose of this study was to demonstrate a relationship between the microstructure and measurements of Egyptian buffalo hair and age. The buffalo studied ranged in age from young to premature to adult (3-8 months, 1.5-3, 4-6, and 8-10 years). The hair was collected from the animals' withers. Cuticle elements were examined using scanning electron microscopy (SEM), light microscopy, and energy-dispersive X-ray (EDX) analysis. Hair shaft diameter increased with age, according to SEM and light microscopy measurements. The values of shaft diameter obtained by SEM of the same animal were 64%-67% of the values obtained by light microscopy due to shrinkage of the hair during the drying process. Additional microscopy measurements revealed that the width of the cortex and medulla increased with age, while the width of the cuticle decreased slightly. The medulla index of four different age groups ranged from 0.56 to 0.61 μm. The average distance between successive scale values increased from 4.83 μm in the young group to 8.86 μm between the ages of 8 and 10 years. The scale pattern had a distinct personality at each stage of age. The hair medulla was in the center and consisted of a mesh-like structure with large pores divided into smaller pores by septa. The cortex was a bundle of fibers that wrapped around the medulla. Light microscopy revealed small oval granules and large streak-like granules in the cortex. EDX spectra revealed that carbon, oxygen, and nitrogen were shown to be more abundant in all age groups of buffalo. In buffalo hair, oxygen was the second most abundant element after carbon. The carbon mass in the examined samples decreased slightly with age (42.31%, 39.18%, 38.88%, and 38.49%), while oxygen increased with age. We concluded that hair measurements varied with age, scale microstructure, and elements, so we estimated buffalo animals' ages up to 10 years. HIGHLIGHTS: The goal was to show a link between the microstructure and measurements of Egyptian buffalo hair and age. Hair shaft diameter increased with age, according to scanning electron microscopy (SEM) and light microscopy measurements. The hair shaft diameter obtained by light microscopy was higher than that obtained by scanning electron microscopy of the same animal; we hypothesized that the difference in hair shaft diameter measured by light microscopy and scanning electron microscopy of the same animal was due to the shrinkage of the hair during the drying process. The width of the cortex and medulla increased with age, while the width of the cuticle decreased slightly. The average distance between successive scale values increased from 4.83 μm in the young group to 8.86 μm between 8 and 10 years old. At each stage of age, the scale pattern had a distinct personality. Carbon, oxygen, and nitrogen were found to be more abundant in the hair of buffalo of all ages and were detected using energy-dispersive X-ray (EDX) spectra. After carbon, oxygen was the second most abundant element in buffalo hair. The carbon mass in the samples studied decreased slightly with age, while the oxygen mass increased. Hair measurements varied according to age, scale microstructure, and elements.

Location-specific pathology analysis of the monopodial pulmonary vasculature in a rabbit model of bronchopulmonary dysplasia-A pilot study

The mammalian pulmonary vasculature consists of functionally and morphologically heterogeneous compartments. When comparing sets of lungs, for example, in disease models or therapeutic interventions, local changes may be masked by the overall heterogeneity of the organ structure. Therefore, alterations taking place only in a sub-compartment may not be detectable by global analysis. In the monopodial lung, the characterization of distinct vessel groups is difficult, due to the asymmetrical branching pattern. In this pilot study, a previously established method to classify segments of the monopodial pulmonary arterial tree into homogeneous groups was employed. To test its suitability for experimental settings, the method was applied to a hyperoxia (HYX, ≥95% oxygen) rabbit model of bronchopulmonary dysplasia and a normoxic control group (NOX, 21% oxygen). The method allowed the identification of morphological differences between the HYX and the NOX groups. Globally visible differences in lumen diameter were pinpointed to specific lung regions. Furthermore, local changes of wall dimension and cell layers in single compartments, that would not have been identifiable in an unfocused analysis of the whole dataset, were found. In conclusion, the described method achieves a higher precision in morphological studies of lung disease models, compared to a common, global analysis approach.

Calcium oxalate crystal macropattern and its usefulness in the taxonomy of Baccharis (Asteraceae)

This study provides a comprehensive account of the various types of calcium oxalate crystals found in the genus Baccharis and assesses the exceptional value of crystal macropatterns for the taxonomy of the genus. The morphotype, occurrence, and chemical composition of the crystals found in the stems and leaves are studied. The 44 species included in this study were selected based on a broad phylogeny-based sampling covering seven subgenera and 31 sections. These species were chosen to represent all the main phylogenetic lineages of Baccharis; thus, the sampling also represents a comprehensive coverage concerning evolutionary significance for such a large and environmentally and economically important plant group. The samples were analyzed by light microscopy, scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS). Several morphotypes of crystals, including druses, crystal sand, styloids and prisms, were present. Based on their chemical composition, the crystals were classified as pure calcium oxalate, mixtures of oxalates and sulfates, and mixtures of oxalates, sulfates, and silica. The crystal macropatterns observed in this study aid in species identification and provide novel data for the taxonomy of Baccharis. RESEARCH HIGHLIGHTS: Most species of Baccharis have a specific crystalline pattern. Each species produces a crystal morphotype or a set of morphotypes specific to it. The crystals observed are formed by calcium oxalate.

Challenges related to the application of analytical methods to control insect meals in the context of European legislation

Since their approval for use in aquaculture in 2017, processed insect proteins have been extensively studied for their nutritional quality in animal feed. This new type of meal is highly promising but requires, as for other products used in animal feed, strict sanitary control in accordance with European legislation. Within this legal framework, light microscopy and PCR remain the official methods but have some analytical limitations that other methods could overcome. This paper aims to provide an overview of the European legislation concerning use of processed insect proteins, but also to highlight the advantages and disadvantages of the official methods for their analysis. It also points out other analytical methods, which have already proved their worth for the analysis of processed animal proteins, which could be used as complementary methods.

Histopathologic features predictive of perivascular deposition of IgA on direct immunofluorescence in cases of leukocytoclastic vasculitis: A retrospective study of 112 specimens

IgA vasculitis is a small-vessel vasculitis subtype with increased risk of systemic involvement. We aimed to investigate if any light-microscopic features can predict the presence of perivascular granular IgA deposits on direct immunofluorescence (DIF) microscopy. We performed a retrospective search of cutaneous pathology reports from our internal and consultation practice (January 1, 2010-October 5, 2021) with a diagnosis of leukocytoclastic vasculitis and accompanying DIF. A blinded dermatopathologist reviewed standard microscopy slides for predetermined histopathological features. Fifty-six biopsies (48 patients) and 56 biopsies (42 patients) met inclusion criteria for IgA+ and IgA-, respectively. The presence of eosinophils and mid and deep dermal inflammation were statistically more associated with IgA- (41/56 [73.2%] and 31/56 [55.4%], respectively) than IgA+ cases (28/56 [50.0%] and 14/56 [25.0%]; p = 0.049 and 0.006, respectively, chi-squared test). Other microscopic criteria recorded were not significantly different between the two groups (p > 0.05, chi-squared and Fisher's exact tests). In this retrospective study of 112 cases, we found that while the absence of eosinophils and absence of mid- and deep inflammation were correlated with increased likelihood of IgA perivascular deposition on DIF, no other histopathological features on light microscopy tested could reliably predict the presence of IgA perivascular deposition on DIF. Therefore, DIF remains a necessary component for the accurate diagnosis of cutaneous IgA vasculitis.

Characterizing Intraindividual Podocyte Morphology In Vitro with Different Innovative Microscopic and Spectroscopic Techniques

Podocytes are critical components of the glomerular filtration barrier, sitting on the outside of the glomerular basement membrane. Primary and secondary foot processes are characteristic for podocytes, but cell processes that develop in culture were not studied much in the past. Moreover, protocols for diverse visualization methods mostly can only be used for one technique, due to differences in fixation, drying and handling. However, we detected by single-cell RNA sequencing (scRNAseq) analysis that cells reveal high variability in genes involved in cell type-specific morphology, even within one cell culture dish, highlighting the need for a compatible protocol that allows measuring the same cell with different methods. Here, we developed a new serial and correlative approach by using a combination of a wide variety of microscopic and spectroscopic techniques in the same cell for a better understanding of podocyte morphology. In detail, the protocol allowed for the sequential analysis of identical cells with light microscopy (LM), Raman spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Skipping the fixation and drying process, the protocol was also compatible with scanning ion-conductance microscopy (SICM), allowing the determination of podocyte surface topography of nanometer-range in living cells. With the help of nanoGPS Oxyo^®, tracking concordant regions of interest of untreated podocytes and podocytes stressed with TGF-β were analyzed with LM, SEM, Raman spectroscopy, AFM and SICM, and revealed significant morphological alterations, including retraction of podocyte process, changes in cell surface morphology and loss of cell-cell contacts, as well as variations in lipid and protein content in TGF-β treated cells. The combination of these consecutive techniques on the same cells provides a comprehensive understanding of podocyte morphology. Additionally, the results can also be used to train automated intelligence networks to predict various outcomes related to podocyte injury in the future.

Tanapox, South Africa, 2022

Tanapox is a rarely diagnosed zoonosis known to be endemic to equatorial Africa. All previously reported human cases were acquired within 10° north or south of the Equator, most recently 19 years ago. We describe a human case of tanapox in South Africa (24° south of the Equator). Expanded surveillance for this pathogen is warranted.

The structure of the eggshell and eggshell membranes of Crocodylus niloticus

The macro- and microstructure, elemental composition, and crystallographic characteristics of the eggshell and eggshell membranes of the Crocodylus niloticus egg was investigated using optical and electron microscopy, energy-dispersive X-ray spectroscopy (EDS), electron backscatter diffraction (EBSD) and computerised tomography. The translucent ellipsoid egg is composed of two basic layers, the outer calcified layer referred to as the shell and an inner organic fibre layer, referred to as the shell membrane. The outer inorganic calcite shell is further divided into an external, palisade and mammillary layers with pore channels traversing the shell. The external layer is a thin layer of amorphous calcium and phosphorus, the underlying palisade layer consist of irregular wedge-shaped crystals composed calcite with traces of magnesium, sodium, sulphur and phosphorus. The crystals are mostly elongated, orientated perpendicular to the shell surface ending in cone-shaped knobs, which forms the inner mammillary layer. The elemental composition of the mammillae is like that of the palisade layer, but the crystal structure is much smaller and orientated randomly. The highest number of mammillae and shell pores are found at the equator of the egg, becoming fewer towards the egg poles. The shell thickness follows the same pattern, with the thickest area located at the equator. The eggshell membrane located right beneath and embedded in the mammillary layer of the shell; it is made up of unorganised fibre sheets roughly orientated at right angles to one another. Individual fibres consist of numerous smaller fibrils forming open channels that run longitudinally through the fibre.

Investigations on the light and scanning electron microscopic structure of the lingual papillae in the angora goat (Capra hircus): II. Mechanical papillae

This study was conducted to examine the light microscopy (LM) and scanning electron microscopic (SEM) structures of mechanical papillae on the tongue in the Angora goat (Capra hircus). As study materials, the tongues of four adult female Angora goats were used. The samples were collected from the dorsal surfaces of the apex, body, root and torus of the tongue and the ventral surfaces of the lingual apex for light and scanning electron microscopic examinations. Three types of mechanical papillae were seen in Angora goat tongue: papilla filiformes, papilla lentiformes and papilla conicae.The filiform papillae were detected in the dorsal surface of the tongue from lingual apex to lingual torus, and in the ventro-lateral of the lingual apex and on both sides of the lingual torus. The morphological differences were observed in filiform papillae according to their location in the tongue. The lenticular papillae settled on the centre of the lingual torus. Two types of these papillae, irregular-round and pyramid-shaped were identified. The conical papillae were scattered all over the lingual torus, except for the central part and were also seen on the root of the tongue. In the light microscopic examination, it was found that mechanical papillae had a stratified squamous epithelium and a varying degree of keratin layer on epithelial surfaces. In this study, by examining the light and scanning electron microscopic structure of the mechanical papillae in the Angora goat tongue, their similarities and differences with other domestic and wild ruminant species were determined.

Larval morphology of the avian parasitic genus Passeromyia: playing hide and seek with a parastomal bar

The enigmatic larvae of the Old World genus Passeromyia Rodhain & Villeneuve, 1915 (Diptera: Muscidae) inhabit the nests of birds as saprophages or as haematophagous agents of myiasis among nestlings. Using light microscopy, confocal laser scanning microscopy and scanning electron microscopy, we provide the first morphological descriptions of the first, second and third instar of P. longicornis (Macquart, 1851) (Diptera: Muscidae), the first and third instar of P. indecora (Walker, 1858) (Diptera: Muscidae), and we revise the larval morphology of P. heterochaeta (Villenueve, 1915) (Diptera: Muscidae) and P. steini Pont, 1970 (Diptera: Muscidae). We provide a key to the third instar of examined species (excluding P. steini and P. veitchi Bezzi, 1928 (Diptera: Muscidae)). Examination of the cephaloskeleton revealed paired rod-like sclerites, named 'rami', between the lateral arms of the intermediate sclerite in the second and third instar larva. We reveal parastomal bars fused apically with the intermediate sclerite, the absence of which has so far been considered as apomorphic for second and third instar muscid larvae. Examination of additional material suggests that modified parastomal bars are not exclusive features of Passeromyia but occur widespread in the Muscidae, and rami may occur widespread in the Cyclorrhapha.

Peripheral blood cells of native pig (Zovawk) of Mizoram, India: Light and scanning electron microscopy analysis

The literature on the blood cells of Zovawk pigs is scanty; thus, this study was designed to elaborate the light microscopy (LM) and scanning electron microscopy (SEM) characterization of blood cells of Zovawk pigs by LM and SEM. Twelve different blood samples were aseptically obtained from adult healthy Zovawk pigs, irrespective of sex. To determine the cytomorphological and cytochemical structures of the many produced constituents of blood, blood smears were stained with various stains. The blood samples were treated with various substrates for cytoenzymatic research, and the alterations were noted. A 1000× magnification Olympus Trinocular Research microscope was used to examine the smears. The blood samples were prepared for electron microscopy according to the standard procedure. The prepared samples were delivered to the Sophisticated Analytical Instrumentation Facility (SAIF), All India Institute of Medical Sciences (AIIMS), New Delhi, for SEM imaging. On LM, pig erythrocytes were spherical and nonnucleated. The cytoplasm of the neutrophils was spherical and included cytoplasmic granules. The eosinophils had prominent cytoplasmic granules and were round. Basophils were infrequently present and had cytoplasmic granules that were clear blue. The sizes of small, medium and large lymphocytes were noted. The monocytes were oval or circular. The platelets ranged in form from asymmetric to round. The blood samples were stained for cytochemical analyses using acid ferrocyanide stain for iron, Sudan black blue stain for lipids, toluidine blue stain for mucopolysaccharides, and periodic acid Schiff's stain for glycogen. The cytoenzymatic characteristics were evaluated and compared with substrates treated with acid phosphatase, alkaline phosphatase, peroxidase, arylsulfatase, cytochrome oxidase, beta-glucuronidase, and succinate dehydrogenase. Erythrocytes appeared as biconcave disks under SEM. Two forms of leukocytes were observed, having a rough and pointed cell surface like a flower. It can be concluded that the LM and SEM morphology of blood cells of Zovawk pigs resembled other domestic animals, however, few differences were observed among the discussed animals.

Morphological changes in striated muscle fibres caused by components of the Thiel embalming method

BACKGROUND

Thiel-fixed body donors are highly valued for surgical training courses. The pronounced flexibility of Thiel-fixed tissue has been postulated to be caused by histologically visible fragmentation of striated muscle. The aim of this study was to analyse whether a specific ingredient, pH, decay, or autolysis could cause this fragmentation in order to modulate the Thiel solution to adapt specimen flexibility specifically to the needs of different courses.

MATERIALS AND METHODS

Striated muscle of the mouse was fixed for different time periods in formalin, Thiel solution, and its individual ingredients, and analysed by light microscopy. Further, pH-values of Thiel solution and its ingredients were measured. In addition, unfixed muscle tissue was histologically analysed including Gram staining to investigate a relationship between autolysis, decomposition, and fragmentation.

RESULTS

Muscle fixed with Thiel solution for 3 months was slightly more fragmentated than muscle fixed for 1 day. Fragmentation was more pronounced after 1 year of immersion. Three individual salt ingredients showed slight fragmentation. Decay and autolysis had no effect on fragmentation, which occurred regardless of the pH of all solutions.

CONCLUSIONS

Fragmentation of Thiel-fixed muscle is dependent on fixation time and most likely occurs due to salts present in the Thiel solution. Adjustment of the salt composition in the Thiel solution with verification of the influence on the fixation effect, fragmentation and flexibility of the cadavers could be performed in further studies.

Labellar Structure of the Maxillaria splendens Alliance (Orchidaceae: Maxillariinae) Indicates Floral Polyphenols as a Reward for Stingless Bees

Several studies have reported stingless Meliponini bees gathering hairs from the labella of Maxillaria spp., including M. ochroleuca, a member of the M. splendens alliance. Such hairs usually contain food materials and are thought to have nutritional value. The papillose labella of representatives of the Maxillaria splendens alliance, however, bear scattered, simple 1-5-celled uniseriate trichomes (hairs) that lack food materials. By contrast, here, as well as polyphenolic compounds, typical labellar papillae usually contain small quantities of starch, protein, and minute droplets of lipid, the last probably involved in the production of fragrance. Towards the labellum apex occur elevated groups of papillae that lack food materials, but contain volatile compounds, probably fragrance precursors. In the past, the terms 'trichomes' or 'hairs' and 'papillae' have been used interchangeably, causing some confusion. Since the trichomes, however, unlike the papillae, are easily detachable and can fragment, it is most likely they, not the papillae, that have previously been observed being collected by bees, but their poor food content indicates that they do not function as food-hairs. Even so, our field observations of M. ochroleuca reveal that stingless bees scrape polyphenol-rich labellar tissue and possibly use this material to produce a resinous, complex, heterogeneous substance commonly referred to as 'bee glue', used for nest construction and repair.

Morphological and Molecular Genetic Analyses of the Genus Vischeria (Eustigmatophyceae, Ochrophyta) in the Algal Collection of Soil Science Institute

Four soil eustigmatophyte algal strains isolated from gray forest soils in Moscow and Tula regions of Russia and deposited in the Algal Collection of Soil Science Institute (ACSSI) were examined by morphological and molecular genetic methods. The strains were assigned to the genus Vischeria on evidence of 18S rRNA gene and ITS2 phylogeny. The strains were morphologically similar to V. magna. However, only one of them, ACSSI 026, clustered with the authentic strain SAG 2554, while the other strains formed a separate independent group. The taxonomy of the genus is problematic because its phylogenetic tree based on the 18S rRNA gene and ITS2 is unresolved, the variable regions V4-V5 and V8-V9 of the 18S rRNA gene are noninformative, and the compensatory base change (CBC) concept fails to work (the concept states that closely related species are distinct if even a single CBC occurs in conserved secondary structure regions of ITS2). The concept of species is presumably possible to develop for Eustigmatophyceae and the genus Vischeria in particular when a greater number of eustigmatophyte algal strains are isolated from various biotopes; plastid genes are used or the total plastid genome is deeply sequenced; and ultrastructural, physiological, and biochemical characteristics are studied in more detail.

The strategic uses of collagen in adherent cell cultures

The culture of adherent mammalian cells involves adhesion to the tissue culture vessel. This requires attachment factors from serum and/or a suitable substrate on the vessel surface. Some cells require collagen or other substrates to promote neurite outgrowth, differentiation or growth. However, laboratories often lack guidance on the selection and/or optimisation of collagen. We model such selection/optimisation work in the PC12 neuronal cell line. PC12 (NS-1 variant) cells require a substrate for adherence. Comparing cell attachment against a series of substrates, we found collagen IV to be optimal. We show by comparison of morphology against a range of concentrations that 10 µg/ml is sufficient for supporting cell attachment, and also differentiation. PC12 cells from Riken Cell Bank do not require a substrate for routine culturing but only for differentiation. As all substrates supported attachment equally well, we used a novel serum-free approach and identified collagen IV as its preferred substrate. For these cells, Dulbecco's modified eagle's medium but not Roswell Park Memorial Institute (RPMI) media supports normal cell attachment. However, coating with collagen IV enabled the cells to grow equally well in RPMI. Hence the strategic use of collagen is essential in laboratories working with anchorage-dependent cell lines.

Temporal accumulation of pigments during colour transformation from white to red in Combretum indicum (L.) DeFilipps (syn. Quisqualis indica L.) flowers

This study focuses on the identification of major anthocyanin following its temporal accumulation in colour changing flowers of Combretum indicum (L.) DeFilipps (syn. Quisqualis indica L.). Separation and identification of pigments governing changes in floral colour were performed using HPLC-DAD. Comparison of chromatographic runs with retention time and UV-Vis spectra of authentic standards determined cyanidin 3-O-glucoside as the major anthocyanin accumulating in the petals. Acid hydrolysis of anthocyanin extracts further confirmed cyanidin as the major anthocyanidin in floral tissue. Light microscopic studies revealed gradual accumulation of pigments in the epidermal and hypodermal cell layers of petals. Antioxidant potentials of floral extracts in ethanol, methanol, water and ethyl acetate were determined by DPPH assay where methanolic extracts showed highest free-radical scavenging capacity, and petals of red stage showed maximum activity. Antioxidative potentials measured in terms of FRAP and ABTS also indicated similar results showing highest activity in the red stage.

Morpho-Functional Characterisation of the Rat Ventral Caudal Nerve in a Model of Axonal Peripheral Neuropathy

Peripheral Neuropathies (PN) are common conditions whose treatment is still lacking in most cases. Animal models are crucial, but experimental procedures should be refined in some cases. We performed a detailed characterization of the ventral caudal nerve to contribute to a more effective assessment of axonal damage in future PN studies. PN was induced via weekly systemic injection of a neurotoxic drug (paclitaxel); we compared the control and PN-affected rats, performing serial neurophysiological evaluations of the caudal nerve for its entire length. On the same nerve portions, we performed light microscopy and ultrastructural pathological observations to assess the severity of damage and verify the integrity of the surrounding structures. Neurophysiological and morphological analyses confirmed that a severe axonopathy had ensued in the PN group, with a length-dependent modality, matching morphological observations. The site of neurophysiological recording (e.g., distance from the base of the tail) was critical for achieving useful data. A flexible experimental paradigm should be considered in animal studies investigating axonal PN, particularly if the expected severity is relevant; the mid-portion of the tail might be the most appropriate site: there damage might be remarkable but neither as extreme as at the tip of the tail nor as mild as at the base of the tail.

Identification of Hypoderma actaeon (Diptera: Oestridae) in red deer (Cervus elaphus) from northern Spain: Microscopy study and molecular analysis

Hypoderma spp. larvae were observed subcutaneously in the dorsal and lumbar regions of red deer (Cervus elaphus) hunted in the province of León (northwestern Spain) causing a myiasis. They were removed and initially classified by their size, shape, color, and location under the skin into the three larval stages that parasitize these animals. The morphological characteristics of the first and second-instar are described and from the features of the third-instar the species was identified as Hypoderma actaeon. To accurately identify this species, five isolates of genomic DNA from the third-instar, two from the second-instar and two from first-instar of H. actaeon were analyzed by PCR analysis of the COI region of mt-DNA. The results confirmed that the examined samples exactly matched with H. actaeon. This study has shown the morphological identification of the three larval stages of H. actaeon and, for the first time, the first and second-instar larvae have been molecularly characterized. Finally, identification of only H. actaeon suggests that this species is the only affecting red deer in the Iberian Peninsula.

Ossa cordis and os aorta in the one-humped camel: Computed tomography, light microscopy and morphometric analysis

The present study describes the morphological characteristics of the camel heart Ossa cordis, and os aorta using computed tomography soft tissue window (CT) alongside 3D render volume reconstructions and light microscopy. The current study techniques demonstrated the Ossa cordis and os aorta in the cardiac window with more precision than the black and white (ghost), and angiography images. Transverse and sagittal CT images additionally demonstrated the presence of Ossa cordis and os aorta. This study is the first to record two small Ossa cordis sinistrum and one os aorta in the camel heart, in addition to the more commonly observed singular, large, os cordis dextrum. The os cordis dextrum was always located in the upper part of the interventricular septum, near to its junction with the atrium, forming an elongated rectangular shape when observed transversally. The wider cranial part was composed from bone, whereas the caudal aspect was narrow and contained both bone and cartilage. Light microscopy identified that the os cordis dextrum consisted of trabecular bone, marrow spaces, and hyaline cartilage. Two Ossa cordis sinistrum were detected on the left side of the heart, one in the right fibrous ring and another in the interventricular septum, microscopy showed that both contained only trabecular bone with osteocytes, osteoblasts, and osteoclasts. At the level of ascending aorta, there was also trabecular bone containing osteocytes, an os aorta.

Slivers of Hair - A Clue to Uncover Silver Hair Syndromes

Silver hair syndromes (SHS) consist of rare autosomal recessive disorders, Chediak-Higashi syndrome (CHS), Griscelli syndrome (GS), and Elejalde disease. CHS is a disorder of vesicle trafficking; characterized by silvery hair, diffuse pigment dilution, immunodeficiency, bleeding diathesis, neurological manifestations, and an accelerated phase due to lymphohistiocytic infiltration. GS is characterized by hypopigmentation of skin and hair, with large clumps of pigment in the hair shaft. There are three types of GS. GS1 and GS2 show neurologic and hematologic impairments; GS3 is restricted to the skin. Some authors suggest that Elejalde syndrome is synonymous with GS Type 1. Here, we report two cases who presented with silver-gray hair but with varied clinical manifestations. With a light microscopic examination of the hair and peripheral smear, a diagnosis has been made. This report highlights the importance of hair shaft microscopy, an inexpensive, noninvasive, and simple tool in the diagnosis of SHS.

Assessing the Agreement of Light Microscopic Evaluation of Oral Lichen Planus Lesions With Associated Direct Immunofluorescence Evaluation

Aim/objective

Assess agreement between light microscopy and direct immunofluorescence (DIF) for histopathologic evaluation of oral lichen planus (OLP).

Methods

Records evaluated included 60 OLP, 16 lichenoid mucositis (LM), and 56 non-OLP/non-LM cases. Cases had both light microscopic and DIF evaluations. Histopathologic parameters of OLP included: (1) hydropic degeneration of the basal cell layer, (2) band-like lymphocytic infiltrate immediately subjacent to the epithelium, and (3) presence of Civatte bodies. Two calibrated examiners independently assessed light microscopic features. Examiners reviewed cases with discordant diagnoses to determine a consensus diagnosis. Intra-rater reliability (IRR), sensitivity, specificity, positive, and negative predictive values (PPV and NPV) were determined.

Results

Of 132 patients, 72.7% were female, average age 61.9 (SD = 13.8). Most common sites were gingiva (37.9%), buccal mucosa (37.1%), and tongue (7.6%). IRR was 0.74 (95% CI: 0.40, 1.00) for the consensus diagnosis and 0.73 (95% CI: 0.39, 1.00) and 0.34 (95% CI: -0.03, 0.72) for the 2 examiners. Comparing consensus and definitive diagnoses: sensitivity of light microscopy: 0.32 (95% CI: 0.20, 0.45); specificity: 0.88 (95% CI: 0.78, 0.94); PPV: 0.68 (95% CI: 0.48, 0.84), and NPV: 0.61 (95% CI: 0.51, 0.70).

Conclusion

Light microscopy alone is not a viable alternative to adjunctive DIF for diagnosis of OLP lesions.

Recent technological advances in correlative light and electron microscopy for the comprehensive analysis of neural circuits

Light microscopy (LM) covers a relatively wide area and is suitable for observing the entire neuronal network. However, resolution of LM is insufficient to identify synapses and determine whether neighboring neurons are connected via synapses. In contrast, the resolution of electron microscopy (EM) is sufficiently high to detect synapses and is useful for identifying neuronal connectivity; however, serial images cannot easily show the entire morphology of neurons, as EM covers a relatively narrow region. Thus, covering a large area requires a large dataset. Furthermore, the three-dimensional (3D) reconstruction of neurons by EM requires considerable time and effort, and the segmentation of neurons is laborious. Correlative light and electron microscopy (CLEM) is an approach for correlating images obtained via LM and EM. Because LM and EM are complementary in terms of compensating for their shortcomings, CLEM is a powerful technique for the comprehensive analysis of neural circuits. This review provides an overview of recent advances in CLEM tools and methods, particularly the fluorescent probes available for CLEM and near-infrared branding technique to match LM and EM images. We also discuss the challenges and limitations associated with contemporary CLEM technologies.