Characterization of Crude and Processed Pulp Cell Walls of Three Selected Mamey Accessions (Mammea americana L.).

Mamey (Mammea americana L.) is a tropical fleshy fruit native from the West Indies and northern South America. It is very appreciated for its flavor and color but has been little described. The present study investigates the composition and histochemistry of the pulp cell walls of three mamey accessions readily available in Martinique. The impact of pulp processing into puree on cell wall composition is evaluated. The histology and rheology of mamey puree are assessed considering these characterizations. Mamey pulp cell wall composition is dominated by highly methyl-esterified pectins (DM: 66.2-76.7%) of high molecular weight, and show few hemicelluloses, mainly xyloglucans. Processing reduced methyl-esterified uronic acid contents and gave purees with significantly different viscosities. Mamey puree was composed of polydisperse particles (20-2343 µm), which size distributions were different depending on the accession: Ti Jacques was dominated by smaller particles (50% had approximated diameters lower than 160 µm), Sonson's by larger particles (50% had approximated diameters higher than 900 µm), and Galion's had an intermediate profile. This new knowledge on mamey pulp is valuable for future works on mamey processing into new food products, even more so for those including cell wall polysaccharide-degrading enzymes.

Lectins As Effective Tools in the Study of the Biliary Network and the Parenchymal Architecture of the Zebrafish (Danio rerio) Liver.

Lectins are carbohydrate-binding proteins with specific affinity to glycoconjugates expressed in various tissues. Lectins are of substantial utility as research, histochemical, and diagnostic tools in mammalian systems. Reactivity of 12 commonly used plant-based lectins was studied in zebrafish liver. Four lectins, tomato lectin (TL), wheat germ agglutinin, concanavalin A, and Jacalin showed strong reactivity to hepatic parenchymal structures. Importantly, TL reacted to glycoconjugates within segments of the larval and adult intrahepatic biliary network, from canaliculi to bile ducts. We provide evidence that lectins can serve as important histochemical tools to investigate the structural and functional characteristics of the zebrafish liver.

First confirmed case of equine pythiosis in Northern Veracruz, Mexico.

A clinical case of an adult horse with invasive, ulcerative, proliferative, pyogranulomatous disease of the skin (tumor) in the shoulder region is presented. The mass had a granulomatous and crater-shaped appearance, with serosanguinous discharge and the presence of fistulas with caseous material. The tumor was removed by surgery and sent to the laboratory for diagnosis. Histopathology was performed using Grocott-Gomori methenamine silver stain. The presence of necrotic material, fibrosis, infiltrated cells, and brown-colored hyphae, characteristic of members of the genus Pythium, were observed. To identify the infecting species, conventional PCRs for the amplification of the ITS-1 was carried out. Histopathological and PCR tests confirmed infection by a Pythium insidiosum strain closely associated with previous records from the US and Central America. Our report represents the first molecularly confirmed case of equine pythiosis in Mexico.

A Comprehensive Study of Meningioma Biomineralization: Morphological, Crystallographic, and Immunohistochemical Aspects.

Biomineralization of brain tissues occurs both in normal and pathological conditions. Dura mater biomineralization is widespread and occurs in 1-72% of cases, depending on the patient's age and research method. The amount of biomineral deposits under the conditions of tumor growth in the meninges only increases, reaching 100% in the case of psammomatous meningiomas. Since calcifications are often found in the meninges, the problem of differential diagnosis with calcified meningiomas arises. A total of 30 samples of meningiomas with signs of biomineralization-dense structure, characteristic crunch, psammoma bodies (group I) and 30 samples of meningiomas without any signs of biomineralization were examined as controls (group II). To detect pathological biomineralization, the meningioma tissue was studied using the methods of macroscopic description, histology, histochemistry, and immunohistochemistry, scanning electron microscopy with microanalysis, and transmission electron microscopy. A significantly higher level of caspase3 and features of the expression of osteoblastic markers (a lower level of OPG expression and a higher level of the presence of RANKL in group I, the absence of fluctuations in the expression of SPARC) may indicate a dystrophic type of development of biomineral deposits in meningiomas.

The Feulgen reaction: from pink-magenta to rainbow fluorescent at the Maffo Vialli's School of Histochemistry.

For over a century, Palazzo Botta (Palace Botta) has housed the University of Pavia's Biomedical Institutes. Illustrious scientists have conducted research and taught at this Palace, making significant contributions to the advancement of natural, biological, and medical science. Among them, Camillo Golgi received the Nobel Prize for discovering the so-called "black reaction." Following Golgi, the Palace continued to be a hub for the development of methodologies and reactions aimed at detecting and quantifying biological components. Maffo Vialli (in the Golgi stream) was the first to establish a Histochemistry Research Group, which began in the naturalistic field and later expanded to the biomedical area. Among the many histochemical studies initiated in the Palace, the Feulgen reaction undoubtedly played a significant role. This reaction, developed R. Feulgen and H. Rossenbeck in 1924, had significant international implications: numerous researchers then contributed to define its fine chemical details, which remained the subject of study for years, resulting in a massive international scientific literature. The Pavia School of Histochemistry also contributed to the evolution and application of this method, which has become a true benchmark in quantitative histochemistry. Giovanni Prenna and the CNR Centre for Histochemistry made significant contributions, as they were already focused on fluorescence cytochemistry. The Pavia researchers made significant contributions to the development of methodology and, in particular, instrumentation; the evolution of the latter resulted in the emergence of flow cytometry and an ever-increasing family of fluorescent probes, which somewhat overshadowed the Feulgen reaction for DNA quantification. The advent of monoclonal antibodies then contributed to the final explosion of flow cytometry in clinical application, almost making young neophytes forget that its roots date back to Feulgen.

Histochemical and morphological evaluation of a glyoxal acid-free fixative.

The application of most chemical fixatives, such as formalin, in the anatomic pathology laboratory requires safety training and hazardous chemical monitoring due to the toxicity and health risks associated with their use. Consequently, the use of formalin has been banned in most applications in Europe; the primary exception is its use in the histology laboratory in lieu of a suitable and safer alternative. Glyoxal based solutions, several of which are available commercially, are the most promising alternative fixatives, because they are based on a mechanism of fixation similar to that of formalin. Unlike formalin, however, glyoxal based solutions do not dissociate from water and therefore do not require ventilation measures such as a fume hood. A primary barrier to the adoption of commercially available glyoxal based solutions is their low pH, which can produce undesirable morphological and antigenic tissue alterations; however, a recently available neutral pH glyoxal product (glyoxal acid free) (GAF) has been developed to mitigate the challenges of low pH. We compared the morphology and histochemistry among tissues fixed in 10% neutral buffered formalin, a commercially available acidic glyoxal product (Prefer), and GAF. Tissues fixed in formalin and Prefer exhibited similar morphology and staining properties; tissues fixed with 2% GAF exhibited deleterious effects.

Lectins as versatile tools to explore cellular glycosylation.

Lectins are naturally occurring carbohydrate-binding proteins that are ubiquitous in nature and highly selective for their, often incompletely characterised, binding partners. From their discovery in the late 1880s to the present day, they have provided a broad palette of versatile tools for exploring the glycosylation of cells and tissues and for uncovering the myriad functions of glycosylation in biological systems. The technique of lectin histochemistry, used to map the glycosylation of tissues, has been instrumental in revealing the changing profile of cellular glycosylation in development, health and disease. It has been especially enlightening in revealing fundamental alterations in cellular glycosylation that accompany cancer development and metastasis, and has facilitated the identification of glycosylated biomarkers that can predict prognosis and may have utility in development of early detection and screening, Moreover, it has led to insights into the functional role of glycosylation in healthy tissues and in the processes underlying disease. Recent advances in biotechnology mean that our understanding of the precise binding partners of lectins is improving and an ever-wider range of lectins are available, including recombinant human lectins and lectins with enhanced, engineered properties. Moreover, use of traditional histochemistry to support a broad range of cutting-edge technologies and the development of high throughout microarray platforms opens the way for ever more sophisticated mapping - and understanding - of the glycome.

Giving bodies to ghosts: locating molecules in the very place where they exert their biological roles.

This paper reviews some of the goals of our investigations published over the years on Rivista di Istochimica Normale e Patologica, Basic and Applied Histochemistry, and the European Journal of Histochemistry - EJH. In a series of papers, we published some of the basic cytochemical features of the sperm cytodifferentiation process for the first time. This was a conceptual and practical prerequisite to the in situ quantitative evaluation of sperm DNA content. We showed that the discrepancy between the expected 1:2 ratio when comparing sperm versus somatic cell DNA content (sperm DNA content is always far low from the theoretical value) is due to DNA losses caused by the hydrochloric treatment entailed by the Feulgen reaction. The knowledge of the specific losses that occur during the various steps of the Feulgen reaction has allowed us to use it critically in Genome Size studies to highlight: - sperm aneuploidy in chromosomally derived subfertility; - the broad variability range of Mammalian genome sizes; - that termites are roaches (after decades of discussion on this topic). In addition, in a seminal paper on human oocytes, we showed (by transmission electron microscopy) a specific chromatin and cytoplasmic organization (both essential for further embryo development) linked to oocyte maturation arrest, a datum quite relevant to treating unmet therapeutic needs in human and veterinary reproduction.

1954-2024: 70 years of histochemical research with the European Journal of Histochemistry.

This Editorial celebrates the 70th anniversary of the European Journal of Histochemistry since its foundation as Rivista di Istochimica Normale e Patologica, and introduces a Special Collection of selected articles on the application of the histochemical approach for investigating cell biological features and processes in animals and plants, and under diseased conditions. The year 2024 is a special one for histochemists, as 100 years ago J.W. Robert Feulgen and H. Rossenbeck introduced the histochemical procedure for the specific stoichiometric staining of DNA in histological samples: to commemorate this influential publication, three papers in the present issue are devoted to the application of the Feulgen reaction at light and electron microscopy, and in cytometry.

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.

Microstructural characterization of the skin in the African straw-coloured fruit bat, Eidolon helvum (Pteropodidae).

The African straw-coloured fruit Bat, Eidolon helvum, is a Yinpterochiroptera bat that is of public health and ecological importance. This study investigated the light microscopic morphology, morphometry and histochemistry of the skin and its glands across the cheek, withers, croup, ventral abdomen, perianal region, wing membrane, intercrural membrane and foot pad of the species. Sweat glands were absent and hypodermis was observed only in the withers, croup and ventral abdomen. The croup had the highest density of hair follicles while the perianal region had the highest density of sebaceous gland acini. The thicknesses of the dermis and epidermis were significantly high in the withers and foot pad respectively. Hair follicles and sebaceous glands were absent in the wing membrane. The sebaceous glands had melanin pigmentation at the periphery and stained positive to Alcian Blue-periodic acid Schiff at the withers and ventral abdomen. Epidermal and dermal thicknesses reported in this study were generally higher than those of Yangochiroptera bats and the presence of sebaceous glands and hair follicles in the wing membrane were variable in different bat species. This study has provided baseline information on the light microscopic morphology and morphometry of the skin and its glands across the various body regions in the African straw-coloured fruit bat. This information would be helpful in the understanding, handling, skin disease treatment and management of the bat in captivity for biomedical research purposes.

The Evolving Role of Artificial Intelligence in Gastrointestinal Histopathology: An Update.

Significant advances in artificial intelligence (AI) over the past decade potentially may lead to dramatic effects on clinical practice. Digitized histology represents an area ripe for AI implementation. We describe several current needs within the world of gastrointestinal histopathology, and outline, using currently studied models, how AI potentially can address them. We also highlight pitfalls as AI makes inroads into clinical practice.

Proceedings of the 39th Congress Italian Society of Histochemistry - 14-16 June 2023, Vulcano Island, Italy.

Proceedings of the 39th Congress of the Italian Society of Histochemistry (SII) - 14-16 June 2023, Hotel Therasia Resort, Vulcano Island, Italy.

Delayed diagnosis of pediatric intra-articular epithelioid sarcoma: a case report and literature review.

BACKGROUND: Epithelioid sarcoma (ES) is a rare form of mesenchymal malignancy that rarely occurs in children. Only seven cases of intra-articular epithelioid sarcoma have been reported in the medical literature. CASE PRESENTATION: In this report, we presented the case of a 13-year-old girl with a delayed diagnosis of ES in the left knee. Her initial diagnosis was mistaken for Pigmented Villonodular Synovitis (PVNS) but ruled out later by the first biopsy. However, the lesion rapidly regrew again after arthroscopy, raising suspicions of malignancy. A comprehensive histochemistry examination was conducted again, leading to the diagnosis of INI-1 negative epithelioid sarcoma. Unfortunately, the girl passed away seven months later due to early metastasis of the tumor. CONCLUSION: Careful consideration should be given to the differential diagnosis of pediatric patients presenting with monoarthritis. This report highlights the importance of early and accurate diagnosis and underscores the necessity for effective treatments for epithelioid sarcoma. Surgical resection or radical surgery is recommended, while novel treatment strategies targeting EZH2 show promise.