Morphometric and histopathological evaluation of modified Elnady's plastinated tissue compared to non-plastinated tissue: Highlighting its relevance for teaching and research

The present study aims to evaluate the morphometric and histopathological properties of Modified Elnady's plastinated tissue after a period compared to non-plastinated tissue. The plastination technique is utilized in research and teaching due to the potential health risks associated with prolonged exposure to formalin. The tissues and organs are permanently dried during plastination and can be used for further anatomical, histopathological and surgical educational purposes. This method involves drying tissue and allowing synthetic materials like glycerin to permeate it. The study compared non-plastinated and plastinated tissue post-plastination to determine if structural alterations differed from those linked to plastination. The study examined the histopathological examination of dogs' skin, muscles, liver, lung, and intestine using formalin-fixed organs for paraffin embedding and previously plastinated organs for a plastinated group. The study examined non-plastinated and plastinated tissues, their histological composition and biometric parameters revealing typical structures in the non-plastinated group. Plasmodiumted tissues exhibited a compacted appearance, volume changes, nuclear clarity, and cytoplasmic hypereosinophilia, with statistical differences between the two groups. The study reveals that plastinated tissues, after 5 years of plastination, maintain their histological architecture well, with some exceptions. Plastinated tissues can be utilized in future microscopic and immunological studies and will be beneficial for teaching and research.

The lateral ulnar collateral ligament: Anatomical and structural study for clinical application in the diagnosis and treatment of elbow lateral ligament injuries

The lateral ulnar collateral ligament (LUCL) is considered one of the main stabilizers of the elbow. However, its anatomical description is not well established. Imaging techniques do not always have agreed upon parameters for the study of this ligament. Therefore, herein, we studied the macro and microanatomy of the LUCL to establish its morphological and morphometric characteristics more precisely. Fifty-five fresh-frozen human elbows underwent dissection of the lateral collateral ligament. Morphological characteristics were studied in detail. Ultrasound (US) and magnetic resonance (MR) were done before dissection. Two specimens were selected for PGP 9.5 S immunohistochemistry. Ten additional elbows were analyzed by E12 sheet plastination. LUCL was identified in all specimens and clearly defined by E12 semi-thin sections. It fused with the common extensor tendon and the radial ligament. The total length of the LUCL was 48.50 mm at 90°, 46.76 mm at maximum flexion and 44.10 mm at complete extension. Three morphological insertion variants were identified. Both US and MR identified the LUCL in all cases. It was hypoechoic in the middle and distal third in 85%. The LUCL was hypointense on MR in 95%. Free nerve endings were present on histology. The LUCL is closely related to the anular ligament. It is stretched during flexion and supination. US and MR can reliably identify its fibers. Anatomical data are relevant to the surgeon who repairs the ligaments of the elbow. Also, to the radiologist and pain physician who interpret imaging and treat patients with pain syndromes of the elbow.

Towards defining muscular regions of interest from axial magnetic resonance imaging with anatomical cross-reference: a scoping review of lateral hip musculature

Background

Measures of hip muscle morphology and composition (e.g., muscle size and fatty infiltration) are possible with magnetic resonance imaging (MRI). Standardised protocols or guidelines do not exist for evaluation of hip muscle characteristics, hindering reliable and valid inter-study analysis. This scoping review aimed to collate and synthesise MRI methods for measuring lateral hip muscle size and fatty infiltration to inform the future development of standardised protocols.

Methods

Five electronic databases (Medline, CINAHL, Embase, SportsDISCUS and AMED) were searched. Healthy or musculoskeletal pain populations that used MRI to assess lateral hip muscle size and fatty infiltration were included. Lateral hip muscles of interest included tensor fascia late (TFL), gluteus maximus, gluteus medius, and gluteus minimus. Data on MRI parameters, axial slice location, muscle size and fatty infiltrate measures were collected and analysed. Cross referencing for anatomical locations were made between MRI axial slice and E-12 anatomical plastinate sections.

Results

From 2684 identified publications, 78 studies contributed data on volume (n = 31), cross sectional area (CSA) (n = 24), and fatty infiltration (n = 40). Heterogeneity was observed for MRI parameters and anatomical boundaries scrutinizing hip muscle size and fatty infiltration. Seven single level axial slices were identified that provided consistent CSA measurement, including three for both gluteus maximus and TFL, and four for both gluteus medius and minimus. For assessment of fatty infiltration, six axial slice locations were identified including two for TFL, and four for each of the gluteal muscles.

Conclusions

Several consistent anatomical levels were identified for single axial MR slice to facilitate muscle size and fatty infiltration muscle measures at the hip, providing the basis for reliable and accurate data synthesis and improvements in the validity of future between studies analyses. This work establishes the platform for standardised methods for the MRI assessment of lateral hip musculature and will aid in the examination of musculoskeletal conditions around the hip joint. Further studies into whole muscle measures are required to further optimise methodological parameters for hip muscle assessment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05439-x.

Plastination of a sperm whale

In 2016, two adult male sperm whales beached off of Yangkou Port in Nantong City, Jiangsu Province, China. The local government planned to preserve them as specimens, one was entrusted to Dalian Hoffen Biological Co., Ltd., and thus became the first sperm whale to be preserved by plastination. The other sperm whale was preserved in Nantong by the traditional stripping method (The skin was preserved, and then the prosthesis was filled into the skin to preserve the specimens. The material of the prosthesis was polyurethane. The outline of the animal was sculpted by suturing the skin like a bag and filling it with polyurethane). Plastination of such a large marine mammal allowed us to view the mutual adaptations of its internal structure to its specific living environment and daily habits. This sperm whale is the largest specimen in the world and this is the first time a sperm whale has been preserved using the plastination method. The plastination process also provides a method for studying the anatomy of large marine mammals for humans to understand deep-sea organisms at close contact and visual level. The plastination of this sperm whale promises to be a world class resource holding tremendous scientific, educational, and artistic value.

The Juxtaoral Organ: From Anatomy to Clinical Relevance

The juxtaoral organ was first described 1885 as a rudimentary structure that developed and disappeared in the embryonic period. Since then, it has been studied further and is now known to be a permanent anatomical structure of considerable importance in clinical, surgical and pathological fields. However, there are no precise and uniform descriptions about its anatomical localization and functional significance. Precise and in-depth anatomical knowledge is crucial to reducing the risk of incorrect identification of the juxtaoral organ, due to fact that this anatomical structure can be misinterpreted as a carcinoma, leading to unnecessary treatments. Therefore, the purpose of this review is to summarize the actual knowledge on the gross and microscopic anatomy of the juxtaoral organ and outline its clinical relevance in order to prevent unnecessary investigations/treatments of this anatomical pitfall. We believe that further studies are still needed to add new perspectives in relation to the juxtaoral organ.

Three-dimensional reconstruction of the orbital retrobulbar vasculature

PURPOSE

The retrobulbar orbital vasculature is known to be complex and variable between individuals. This study aimed to produce a method to map the retrobulbar vessels, to generate 3D reconstructions, to visualise and to improve our understanding of their complexity.

METHODS

Five human orbits donated under the Human Tissue Act (2004) were fixed in formalin, decalcified in 10% formic acid, and dehydrated in acetone at -20°C. Specimens were impregnated with epoxy resin, cured, and cut into 0.3 mm sections. Sections were stained with Gomori's trichrome stain, imaged, and reconstructed using 3D reconstruction software (BioVis3D, version 3.1).

RESULTS

The arterial system was reconstructed in all five specimens. The superior ophthalmic vein (SOV) and the central retinal vein (CRV) were reconstructed in four specimens. E12 sheet plastination showed excellent results for histological analysis at a macroscopic level; however, anatomical topology was not entirely preserved on a microscopic level. Gomori's trichrome stain gave excellent results in highlighting axial sections of the arterial walls and their tunics, including finer calibre vessels, thus allowing detailed reconstruction of the arterial vasculature. Miller's stain for elastin showed poor results in differentiating vessels from soft tissue; venous vasculature was poorly identified with both stains.

CONCLUSIONS

This study provided a detailed anatomical model of the retrobulbar orbital vascular system, a method that can be used for further studies to form a database relating to the topography of the arterial system. These models may be employed for teaching, and possible surgery planning, for both trainees and ophthalmic surgeons.

Extraction of DNA from plastinated tissues

INTRODUCTION

Plastination allows anatomical samples to be preserved in excellent condition for an indefinite period, free of formalin, and in a format that allows biosafe manipulation by students, academics, and researchers. As with other tissue preservation techniques, it is important to establish the level of conservation of deoxyribonucleic acid (DNA) for use in future applications. The object of the present work was to extract and evaluate DNA from plastinated tissues.

METHODS

We used samples of liver from Canis lupus familiaris and skeletal muscle from Rattus norvegicus, Sprague-Dawley strain, extracted from specimens plastinated with silicone at room temperature. The tissue samples were deplastinated by incubation in 5% sodium methoxide dissolved in methanol for 24 or 48 h. The samples were divided into two equal parts and DNA was extracted using two different protocols. After extraction, the DNA was quantified by fluorometry and its integrity was assessed by electrophoresis in a 1% agarose gel.

RESULTS AND DISCUSSION

A high yield of DNA was obtained from the deplastinated samples and the DNA was intact. Plastinated tissues have proven to be stable and easily managed. They can also be used for examination under light and electron microscopes. The DNA extraction technique used here allowed us to obtain intact DNA from samples plastinated with silicone at room temperature, without previous fixing. This technique may allow tissue specimens to be preserved for retrospective studies of archived samples of normal and pathological anatomy in the fields of basic, clinical, forensic, and epidemiological sciences.

CONCLUSIONS

The extracted DNA was intact and suitable for use in subsequent applications. Obtaining whole DNA from plastinated samples using tissue preservation protocols that preserve the tissue for use in subsequent applications, like real-time PCR, opens up many possibilities, with applications in the basic and clinical sciences, epidemiology, and forensic science.

Fibrous configuration of the fascia iliaca compartment: An epoxy sheet plastination and confocal microscopy study

Background and Objectives: The underlying anatomical mechanism of the ultrasound-guided fascia iliaca compartment (FIC) block for anaesthesia and analgesia in the lower limb has not been illuminated and numerous variations were attempted to achieve an optimal needle placement. This study aimed to define the fibrous configuration of the FIC. Methods: A total of 46 adult cadavers were studied using dissection, latex injection, epoxy sheet plastination and confocal microscopy. Results: (1) The fascia iliaca originated from the peripheral fascicular aponeurotic sheet of the iliopsoas. (2) The FIC was a funnel-shaped adipose space between the fascia iliaca and the epimysium of the iliopsoas, had a superior and an inferior opening and contained the femoral and lateral femoral cutaneous nerves but not obturator nerve. (3) The estimated volume of the FIC in the cadavers was about 23 mls, of which about one third was below the level of the anterior superior iliac spine. Conclusions: This study revealed that the fascia iliaca was aponeurotic and may be less permeable for the local anesthetics. Conclusions: The FIC contained only the femoral and lateral femoral cutaneous nerves and communicated with the extraperitoneal space and femoral triangle adipose space via its superior and inferior opening, respectively.

Quantification of fat in the posterior sacroiliac joint region: fat volume is sex and age dependant

Fat is appreciated as a structural component of synovial joints. It may serve a shock-absorbing function for the incongruent surfaces, vessels and ligaments, but has not been investigated in the posterior sacroiliac joint (PSIJ). Sixty-six cadaveric hemipelves were serially-sectioned and photographed. The amount of visible fat in the PSIJ was quantified using a modified version of Cavalieri’s method. Total volume, fat volume and fat percentage of the PSIJ were calculated in predefined sub-regions. Fat is consistently present in the PSIJ (1.9 ± 1.3 cm³). Fat volume correlates with the PSIJ total volume (p < 0.0001; r = 0.73) and age (p = 0.024; r = 0.24), and is smaller in males (1.4 ± 0.8 cm³) than females (2.4 ± 1.5 cm³). Fat volumes in the middle and inferior sub-regions of the PSIJ show side- (p < 0.0001) and sex-differences (p = 0.013 females, middle sub-region). Age and PSIJ total volume correlate between sexes in various sub-regions (p = 0.05 females superior sub-region; males inferior sub-region). Fat percentage differs between sexes and sub-regions (p = 0.018 females, superior sub-region) but is independent of age and sides. The presence of fat within the PSIJ is a normal finding and shows sex-dependant and age-related differences. It is unclear whether fat is linked to age-related degeneration or has a shock-absorbing role in stress- and load-dissipation in the PSIJ.

Development of an ultrathin sheet plastination technique in rat humeral joints with osteoarthritis induced by monosodium iodoacetate for neovascularization study

Injection with monosodium iodoacetate (MIA) is widely used to produce osteoarthritis (OA). Ultrathin sheet plastination has been used to study the morphology of structures, with strong application in anatomical education and research. Our aim was to carry out, for the first time, ultrathin sheet plastination of rat humeral joints to observe the neovascularization provoked by OA. We injected 0.1 mL of MIA into the left humeral joints of ten Sprague-Dawley rats. The right shoulders of the same rats were used as control. Sixteen weeks after the injection, the animals were euthanized and were given an immediate red epoxy resin injection through the thoracic aorta. The samples were fixed in 10% formalin, prior to the plastination process, without decalcification. Samples were dehydrated with acetone (100%) at - 25 °C, for 10 days. Later, for degreasing, samples were immersed in methylene chloride at room temperature during 1 week. Forced impregnation was performed inside a stove within a vacuum chamber. The plastinated blocks obtained were cut with a slow velocity diamond blade saw. Slices were placed in curing chambers to achieve curing and final tissue transparentation. 230 μm thickness slices were obtained. The slices were analyzed under magnifying glass and microscope, achieving visualization of OA neovascularization. The cartilage affected by OA loses its ability to remain avascular, and blood vessels invade it from the subchondral bone to the calcified and uncalcified cartilage. Ultra-thin sheet plastination is useful to observe articular cartilage neovascularization, caused by OA induced with MIA in humeral rat joint.