Terminologia Histologica 10 years on: some disputable terms in need of discussion and recent developments

Terminological discrepancies and novelties in the histological description of the female genital system: proposed amendments for clinical-translational anatomy

Histological terminology of the female genital organs is currently a part of the internationally accepted nomenclature Terminologia Histologica (TH), the latest edition of which dates back to 2008. Many new discoveries have been documented within 16 years since then, and many discrepancies have been found. This paper aims to revise the terminology from clinical and educational perspectives comprehensively. The authors thoroughly searched the current edition of "Terminologia Histologica: International Terms for Human Cytology and Histology," focusing on missing and controversial terms in the chapter Female genital system. The authors identified six controversial and ambiguous terms and four missing important histological terms. The authors also discussed the addition of less used eponymic terms in the histological description of female genital organs like Hamperl cells, Popescu cells, Kroemer lacunae, Balbiani bodies, Call-Exner bodies, membrane of Slavianski, nabothian cysts, or anogenital sweat glands of van der Putte. We expect the second and revised edition of the TH to be published soon and hope that the Federative International Program on Anatomical Terminology will approve and incorporate all these propositions and suggestions. We also strongly recommend using the official internationally accepted Latin and English histological nomenclature-the TH, either in oral or written form, both in theoretical and clinical medicine.

Revisiting the Latin vocabulary of Terminologia Histologica: I. Nouns

Almost 20% of the Latin nouns (193/993) in Terminologia Histologica (TH), the international standard nomenclature for human histology and cytology, display linguistic problems, particularly in the areas of orthography, gender, and declension. Some anatomists have opposed efforts to restore the quality of the Latin nomenclature as pedantry, preferring to create or modify Latin words so that they resemble words in English and other modern languages. A Latin microanatomical nomenclature is vulnerable to the criticism of anachronism, so the requirement for the use of authentic Latin, including derivation of new words from Greek and Latin words rather than from modern languages, if possible, may be even greater than it is for the anatomical nomenclature. The most common problem identified here appears to have been caused by derivation of Latin nouns by addition of -us and -um second declension endings to English words. Many Latin nouns (128) in TH contain one of six morphemes that have been treated this way even though the original Greek words are either first declension masculine or third declension neuter nouns. Ironically, deriving Latin nouns directly from Greek morphemes often results in words that look more familiar to speakers of Romance and Germanic languages than those derived indirectly through modern languages (e.g., astrocyte, collagene, dendrita, lipochroma, osteoclasta and telomere instead of astrocytus, collagenum, dendritum, lipochromum, osteoclastus, and telomerus).

Telocytes and Other Interstitial Cells 2.0: From Structure to Function

Interstitial cells are often seen as those cells that fill the space between parenchymal cells, responsible for fulfilling the function of an organ [...].

Cardiac Telocytes 16 Years on-What Have We Learned So Far, and How Close Are We to Routine Application of the Knowledge in Cardiovascular Regenerative Medicine?

The regeneration of a diseased heart is one of the principal challenges of modern cardiovascular medicine. There has been ongoing research on stem-cell-based therapeutic approaches. A cell population called telocytes (TCs) described only 16 years ago largely contributed to the research area of cardiovascular regeneration. TCs are cells with small bodies and extremely long cytoplasmic projections called telopodes, described in all layers of the heart wall. Their functions include cell-to-cell signaling, stem-cell nursing, mechanical support, and immunoregulation, to name but a few. The functional derangement or quantitative loss of TCs has been implicated in the pathogenesis of myocardial infarction, heart failure, arrhythmias, and many other conditions. The exact pathomechanisms are still unknown, but the loss of regulative, integrative, and nursing functions of TCs may provide important clues. Therefore, a viable avenue in the future modern management of these conditions is TC-based cell therapy. TCs have been previously transplanted into a mouse model of myocardial infarction with promising results. Tandem transplantation with stem cells may provide additional benefit; however, many underresearched areas need to be addressed in future research before routine application of TC-based cell therapy in human subjects. These include the standardization of protocols for isolation, cultivation, and transplantation, quantitative optimization of TC transplants, cost-effectivity analysis, and many others.

Variant Anatomy and Its Terminology

Variant anatomy, which is an integral part of anatomical science, is related to abnormalities in the human body structure. Our understanding of variant anatomy is based on thousand years of anatomical experience. These abnormalities generally do not interfere with the function of the human body and do not typically manifest as pathological nosological units. However, under certain conditions, these abnormalities can worsen existing pathological states or even evoke new ones. Understanding variant anatomy is a basic skill not only of mere anatomists, but also of clinicians who work in fields involving both diagnostic techniques and therapeutic interventions. To gain and retain a good knowledge of the most frequent and clinically relevant anatomical variations, a simple, clear, and exactly defined nomenclature of variant structures is needed. A list of items comprising variant anatomy, which have been incorporated into the internationally accepted nomenclatures Terminologia Anatomica (1998) and Terminologia Neuroanatomica (2017), is described and analyzed. Examples of the most common anatomical variations related to terminology are mentioned, and variant anatomy as a whole and its role in understanding current anatomy are discussed.

Lymphatic lacunae of the human eye conjunctiva embedded within a stroma containing CD34+ telocytes

An accurate identification of telocytes (TCs) was limited because of the heterogeneity of cell types expressing the markers attributed to TCs. Some endothelial lineage cells also could fit within the pattern of TCs. Such endothelial cells could line conjunctival lacunae previously assessed by laser confocal microscopy. We have been suggested that an accurate distinction of TCs from endothelial cells in the human eye conjunctiva could be achieved by use of CD31, CD34 and D2‐40 (podoplanin); and that the conjunctival lacunae are in fact lymphatic. We aimed as testing the hypothesis by an immunohistochemical study on human eye conjunctiva biopsy samples. Samples of human eye conjunctiva from 30 patients were evaluated immunohistochemically by use of the primary antibodies: CD34, D2‐40 and CD31. D2‐40 was equally expressed within epithelia and laminae propria. Basal epithelial cells were D2‐40 positive. Within the stromal compartment, the lymphatic marker D2‐40 labelled several lymphatic vessels. CD31 labelled both vascular and lymphatic endothelial cells within the lamina propria. When capillary lymphatics were tangentially cut, they gave the false appearance of telocytes. Blood endothelial cells expressed CD34, whereas lymphatic endothelial cells did not. Stromal CD34‐expressing cells/telocytes were found building a consistent pan‐stromal network which was equally CD31‐negative and D2‐40‐negative. The conjunctival lymphatic lacunae seem to represent a peculiar anatomic feature of eye conjunctiva. They are embedded within a CD34‐expressing stromal network of TCs. The negative expression of CD31 and D2‐40 should be tested when discriminating CD34‐expressing TCs.