CD301 and LSECtin glycan-binding receptors of innate immune cells serve as prognostic markers and potential predictors of immune response in breast cancer subtypes.

Glycosylation is a prominent posttranslational modification, and alterations in glycosylation are a hallmark of cancer. Glycan-binding receptors, primarily expressed on immune cells, play a central role in glycan recognition and immune response. Here, we used the recombinant C-type glycan-binding receptors CD301, Langerin, SRCL, LSECtin, and DC-SIGNR to recognize their ligands on tissue microarrays (TMA) of a large cohort (n = 1859) of invasive breast cancer of different histopathological types to systematically determine the relevance of altered glycosylation in breast cancer. Staining frequencies of cancer cells were quantified in an unbiased manner by a computer-based algorithm. CD301 showed the highest overall staining frequency (40%), followed by LSECtin (16%), Langerin (4%) and DC-SIGNR (0.5%). By Kaplan-Meier analyses, we identified LSECtin and CD301 as prognostic markers in different breast cancer subtypes. Positivity for LSECtin was associated with inferior disease-free survival in all cases, particularly in estrogen receptor positive (ER+) breast cancer of higher histological grade. In triple negative breast cancer, positivity for CD301 correlated with a worse prognosis. Based on public RNA single-cell sequencing data of human breast cancer infiltrating immune cells, we found CLEC10A (CD301) and CLEC4G (LSECtin) exclusively expressed in distinct subpopulations, particularly in dendritic cells and macrophages, indicating that specific changes in glycosylation may play a significant role in breast cancer immune response and progression.

Specificity of widely used lectins as probed with oligosaccharide and plant polysaccharide arrays.

Glycan-binding specificity was studied for Jacalin, RCA 120, SBA, PHA-L, PHA-E, WGA, UEA, AAL, LTL, LEL, SNA, DSA, LCA, MAH and Con A, lectins widely used in histochemistry. Oligosaccharide- and polysaccharide-based glycan arrays were applied. Expected specificity was confirmed for only 6 of the 15 lectins and the glycan binding profiles of some lectins were dramatically broader than generally accepted. WGA, LEL and DSA known as chitooligosaccharide-specific, were unexpectedly polyreactive, binding to other glycans with the same affinity as to chitobiose, ABH antigens and oligolactosamines (unsubstituted and sialylated). SBA, in addition to expected binding to glycans with terminal GalNAcα, also had high affinity for the GM1 ganglioside. MAH demonstrated much higher affinity to a variety of sulfated glycans compared to Neu5Acα2-3Galß1-3GalNAcα. Contrary to the common view, LCA demonstrated the maximum binding to (GlcNAcß1-2Manα1)2-3,6-Manß1-4GlcNAcß1-4GlcNAc N-glycan, while it had no interaction with corresponding Gal or Neu5Ac terminated versions. This observed polyreactivity of some lectins casts doubt on their use in accurately determining the presence of a specific glycan structure by histochemical studies. However, comparisons of sera from healthy and diseased individuals with help of a lectin array can easily establish differences in glycosylation patterns and presumptive glycan identities, which can later be clarified using more accurate methods of structural analysis.

Development of monoclonal antibodies against oropouche virus and its applicability to immunohistochemical diagnosis.

Orthobunyavirus oropouche ense virus (OROV), the causative agent of Oropouche fever, is widely dispersed in Brazil and South America, causing sporadic outbreaks. Due to the similarity of initial clinical symptoms caused by OROV with other arboviruses found in overlapping geographical areas, differential diagnosis is challenging. As for most neglected tropical diseases, there is a shortage of reagents for diagnosing and studying OROV pathogenesis. We therefore developed and characterized mouse monoclonal antibodies and, one of them recognizes the OROV nucleocapsid in indirect immunofluorescent (IFA) and immunohistochemistry (IHC) assays. Considering that it is the first monoclonal antibody produced for detecting OROV infections, we believe that it will be useful not only for diagnostic purposes but also for performing serological surveys and epidemiological surveillance on the dispersion and prevalence of OROV in Brazil and South America.

The comparative morphology of the oral cavity glands in captive South African painted dogs (Lycaon pictus pictus) and captive fennec foxes (Vulpes zerda) (Carnivora: Canidae).

BACKGROUND: The African painted dog is classified as a relic canid lineage, inhabiting areas south of the Sahara. The fennec fox is the smallest member of the Canidae family, found in the Arabian Peninsula and northern Sahara. METHODS: The gross anatomy and light microscopic examination of the oral cavity glands were studied in five adult captive South African painted dogs and five adult captive fennec foxes from the Wroclaw Zoological Garden, Poland. In this research, the zygomatic gland, monostomatic sublingual gland, polystomatic sublingual gland, mandibular gland, and parotid gland were examined for their topography, morphometry, histology, and histochemistry using hematoxylin and eosin, azan trichrome, mucicarmine, PAS, AB pH 1.0, AB pH 2.5, AB pH 2.5 PAS, and HID. RESULTS: We found that the parotid glands were consistently the largest, followed by the mandibular and sublingual glands (both monostomatic and polystomatic). The zygomatic gland was the smallest in both South African painted dogs and fennec foxes. Interestingly, there were noticeable differences in the size, shape, and even composition of the secretory products between the two species. The zygomatic and polystomatic sublingual glands in the South African painted dog and the fennec fox were complex branched tubular. In the South African painted dog, the monostomatic gland was a branched tubular compound gland, while in the fennec fox, it was a branched tubuloalveolar compound gland. The mandibular gland in hunting dogs was a branched tubular compound gland, while in the fennec fox a branched tubuloalveolar compound gland. The parotid gland in the fennec fox was a branched acinar compound gland, whereas in the painted dog was a branched tubuloacinar. CONCLUSIONS: The basic structure of their glands is similar to that of other terrestrial carnivores, indicating a shared evolutionary origin and function. However, differences in the composition of their secretory products can reflect adaptations to their specific diets. This research provides valuable insights for veterinary medicine and underscores the importance of further studies. By analyzing wild canid populations and including a broader range of species with diverse diets, we could gain a deeper understanding of how diet influences salivary gland morphology within the Canidae.

Characteristics of the Integument of Phyllomedusa burmeisteri (Anura, Phyllomedusidae) and Boana semilineata (Anura, Hylidae) Males Can Contribute to Understanding its Relation to Habitat.

The integument of anurans plays vital physiological roles, crucial for understanding the species' survival in their environment. Despite its significance, there are few studies describing the cutaneous morphology of anurans from the Brazilian Atlantic Forest. This study aimed to characterize the integument of Phyllomedusa burmeisteri and Boana semilineata in males using microscopic and histochemical approaches. Histological sections were stained with various dyes, and additional fragments underwent electron microscopy and energy-dispersive X-ray spectroscopy. Results showed different projections on the dorsal and ventral regions of males from these species, without the Eberth-Katschenko layer. Differences in the arrangement of chromatophore cells in regions with varying solar incidence were observed in the spongy dermis. Various gland types were identified, aiding taxonomic differentiation and validation of behavioral data. Both species had seromucous and granular glands, while only P. burmeisteri displayed lipid glands. Histochemical analysis revealed higher production of polysaccharides and proteins, contributing to the integument's moisture and protection. Lipid secretions in P. burmeisteri helped waterproof the integument more effectively against desiccation. This study concludes that analyzing anuran integument provides valuable insights into their behavior, with integument composition potentially influenced by habitat choice among different species.

Antillean manatee (Trichechus manatus manatus Linnaeus, 1758) Tongue Morphology and Adaptive Herbivorous Implications.

Morphological study of the tongue is an interesting way of understanding evolutionary processes associated with feeding habits. Therefore, the aim of the present study was to describe the tongue morphology of the Antillean manatee and to understand possible morphological relationships with its way of capturing food. Macroscopic dissections and light and scanning electron microscopy analyses of seven manatee tongues were performed. The tongue in Antillean manatees is a muscular and robust organ, divided into apex, body, and root. It is firmly adhered to the floor of the oral cavity. Lingual papillae were distributed over the entire tongue surface. They were identified as filiform papillae concentrated in the apex. Fungiform papillae were present on the apex and lateral regions. Foliate papillae were located on the dorsolateral portion of the root. Lentiform papillae were located across the dorsal tongue surface. The mucosa was lined by a keratinized stratified squamous epithelium presenting compound tubuloacinar glands and taste buds in the foliate papillae. The tongue of the Antillean manatee is similar to other Sirenia species, both of which share a completely herbivorous diet.

Utilization of Advanced Microscopy Techniques and Energy-dispersive X-ray Spectroscopy to Characterize Three Piper Species Related to Kava.

Macro- and microscopic techniques have long been used to describe plant materials and establish plant structural profiles. These techniques are commonly used in botanical authentication to identify the genuine and closely allied species used in botanical research. Advanced microscopic techniques were used in this study to differentiate three different Piper species used as kava or kava-kava. The genuine species is Piper methysticum and the other two species commonly called false-kava or kava-kava, are Piper auritum and Piper excelsum. Macroscopic characteristics, including a black-spotted stem and fibrous root, are characteristic of P. methysticum, whereas the stem of P. auritum is greenish with no spots, and the P. excelsum stem is purple-pink. Microscopic attributes include the characteristic collenchyma of stems and the pattern of arrangement of peripheral and medullary vascular bundles. The starch grains are smaller in P. excelsum than in the other two species. Energy-dispersive X-ray spectroscopy analysis of the crystals indicates the expected calcium, magnesium, and silica, along with lesser amounts of sodium, and potassium. The crystals present in the Piper species vary in shape, size, and elemental composition. Combining macro- and microscopical techniques and resulting characteristics are instrumental in differentiating the three Piper species.

Comprehensive Quality Assessment of Brassica napus L. Seeds via HPTLC, LC-QToF, and Anatomical Investigation.

The Brassicaceae family, commonly referred to as cruciferous plants, is globally cultivated and consumed, with the Brassica genus being particularly renowned for its functional components. These vegetables are rich sources of nutrients and health-promoting phytochemicals, garnering increased attention in recent years. This study presents a comprehensive microscopic, chromatographic, and spectroscopic characterization of Brassica napus L. seeds from Kazakhstan aimed at elucidating their morphological features and chemical composition. Microscopic analysis revealed distinct localization of flavonoids, total lipids, and alkaloids. High-performance thin-layer chromatography (HPTLC) analysis of seed extracts demonstrated a complex chemical profile with significant quantities of non-polar compounds in the hexane extracts. Additionally, methanolic extracts revealed the presence of diverse chemical compounds, including alkaloids, flavonoids, and glucosinolates. The chemical composition exhibited varietal differences across different Brassica species, with B. napus L. seeds showing higher concentrations of bioactive compounds. Furthermore, liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QToF-MS) analysis provided insights into the chemical composition, with sinapine isomers, feruloyl, and sinapoyl choline derivatives as major compounds in the seeds. This study contributes to a better understanding of the chemical diversity and quality control methods' approximations of B. napus L. seeds, highlighting their importance in functional food and nutraceutical applications.

Histochemical research of enzymes involved in cellular digestion in the digestive tract of tub gurnard, Chelidonichthys lucerna.

The tub gurnard Chelidonichthys lucerna (Linnaeus, 1758), Triglidae, is an opportunistic, demersal carnivorous fish. Data on the digestive enzymes of tub gurnard have not been reported in the literature. Therefore, the aim of this research was to investigate the distribution and intensity of alkaline phosphatase, acid phosphatase, non-specific esterase, and aminopeptidase in the digestive tract of tub gurnard. To investigate data about those enzymes tissue samples of the esophagus, anterior and posterior part of the stomach, pyloric caeca, anterior, middle and posterior part of the intestine proper, and rectum were taken. Azo-coupling methods were used to detect the enzymatic reactions. The intensities of the reactions were measured using ImageJ software. Alkaline phosphatase, acid phosphatase, and non-specific esterase activities were found in all parts of the digestive tract. The brush border of the pyloric caeca and intestine proper were the main sites of alkaline phosphatase reaction, with intensity decreasing toward the posterior parts of the digestive tract. The high intensities of acid phosphatase were found in the epithelium of the anterior part of the stomach, pyloric caeca, anterior part of the intestine proper, and in the rectum. The intensity of non-specific esterase was mainly increased from the anterior to the posterior parts of the digestive tract. Aminopeptidase activity was found in the esophagus, pyloric caeca, and intestine proper. Our results suggest that the entire digestive tract of the tub gurnard is involved in the digestion and absorption of dietary components.

Multiple Primary Melanoma Associated with CDKN2A Mutation-Case Report and Review of the Literature.

The CDKN2A gene remains understudied in melanoma compared to BRAF alterations. Inactivation of this tumor suppressor gene through homozygous deletions in the 9p21 chromosomal region leads to cellular proliferation and disrupts pro-apoptotic pathways. Genetic changes in CDKN2A are linked to multiple primary melanomas (MPM), with patients diagnosed with melanoma facing an elevated risk of developing additional primaries. We present the rare case of a 72-year-old Caucasian woman with nine metastasizing melanomas across diverse anatomical sites, posing a diagnostic challenge. Initial diagnosis in 2022 revealed ulcerated superficial spreading melanomas, progressing to intradermal and papillary dermal populations with neurotropism and angiotropism by early 2023. Lymph node metastases were identified, classifying the condition as pT3b N3b. Subsequent assessments in April 2023 revealed clinically suspicious melanocytic lesions diagnosed as intradermal and traumatized junctional nevi. In late 2023, cutaneous pigmented lesions and subcutaneous metastases were confirmed as nodular nevoid low-CSD multiple melanomas. Fluorescence in situ hybridization testing revealed homozygous CDKN2A deletion, necessitating close multidisciplinary collaboration for an optimized care plan for effective monitoring and intervention in this intricate clinical scenario. In summary, this case report highlights the diagnostic challenges of MPM in a single patient. Stressing the importance of immuno-histochemistry and CDKN2A genetic testing, our findings underscore the crucial role of these tools in accurately distinguishing malignant melanocytic proliferations from nevi and characterizing MPM cases.

Pathological Remodeling of the Gut Barrier as a Prodromal Event of High-Fat Diet-Induced Obesity.

Intestinal barrier alterations represent a primum movens in obesity and related intestinal dysfunctions. However, whether gut barrier remodeling represents prodromal events in obesity before weight gain, metabolic alterations, and systemic inflammation remains unclear. Herein, we examined morphologic changes in the gut barrier in a mouse model of high-fat diet (HFD) since the earliest phases of diet assumption. C57BL/6J mice were fed with standard diet (SD) or HFD for 1, 2, 4, or 8 weeks. Remodeling of intestinal epithelial barrier, inflammatory infiltrate, and collagen deposition in the colonic wall was assessed by histochemistry and immunofluorescence analysis. Obese mice displayed increased body and epididymal fat weight along with increased plasma resistin, IL-1ß, and IL-6 levels after 8 weeks of HFD. Starting from 1 week of HFD, mice displayed (1) a decreased claudin-1 expression in lining epithelial cells, (2) an altered mucus in goblet cells, (3) an increase in proliferating epithelial cells in colonic crypts, (4) eosinophil infiltration along with an increase in vascular P-selectin, and (5) deposition of collagen fibers. HFD intake is associated with morphologic changes in the large bowel at mucosal and submucosal levels. In particular, the main changes include alterations in the mucous layer and intestinal epithelial barrier integrity and activation of mucosal defense-enhanced fibrotic deposition. These changes represent early events occurring before the development of obesity condition that could contribute to compromising the intestinal mucosal barrier and functions, opening the way for systemic dissemination.

Histochemistry and Cell Biology-a glance into the past and a look ahead.

At the occasion of the 65th anniversary of Histochemistry and Cell Biology, we browse through its first ten years of publication and highlight a selection of papers from the early days of enzyme, protein, and carbohydrate histochemistry. In addition, we narrate recent progress to identify, quantify, and precisely determine the tissue localization of proteins and lipids, and small molecules by the combination of spectroscopic techniques and histology.

Chloroacetate esterase reaction combined with immunohistochemical characterization of the specific tissue microenvironment of mast cells.

This study provides a combined histochemical method for detecting enzyme activity of chloroacetate esterase simultaneously with immunolabeling of the components of a specific tissue microenvironment on formalin-fixed, paraffin-embedded specimens. Chromogenic detection of the molecular targets within and outside the mast cells provides novel options in determining the histoarchitectonics of organ-specific mast cell populations, studying the functional significance of chloroacetate esterase and specifying the immune landscape of the tissue microenvironment.

The larval midgut of Anopheles, Aedes, and Toxorhynchites mosquitoes (Diptera, Culicidae): a comparative approach in morphophysiology and evolution.

The mosquito larval midgut is responsible for acquiring and storing most of the nutrients that will sustain the events of metamorphosis and the insect's adult life. Despite its importance, the basic biology of this larval organ is poorly understood. To help fill this gap, we carried out a comparative morphophysiological investigation of three larval midgut regions (gastric caeca, anterior midgut, and posterior midgut) of phylogenetically distant mosquitoes: Anopheles gambiae (Anopheles albimanus was occasionally used as an alternate), Aedes aegypti, and Toxorhynchites theobaldi. Larvae of Toxorhynchites mosquitoes are predacious, in contrast to the other two species, that are detritivorous. In this work, we show that the larval gut of the three species shares basic histological characteristics, but differ in other aspects. The lipid and carbohydrate metabolism of the An. gambiae larval midgut is different compared with that of Ae. aegypti and Tx. theobaldi. The gastric caecum is the most variable region, with differences probably related to the chemical composition of the diet. The peritrophic matrix is morphologically similar in the three species, and processes involved in the post-embryonic development of the organ, such as cell differentiation and proliferation, were also similar. FMRF-positive enteroendocrine cells are grouped in the posterior midgut of Tx. theobaldi, but individualized in An. gambiae and Ae. aegypti. We hypothesize that Tx. theobaldi larval predation is an ancestral condition in mosquito evolution.

Osmophores and petal surface traits in Bignonieae species.

This study characterizes the osmophores and corolla traits in 18 species of Bignonieae Dumort., a Bignoniaceae tribe occurring in the Cerrado, a neotropical savanna in Brazil. To detect osmophore distribution, whole, newly opened flowers were immersed in Neutral Red Solution. Samples from the corolla tube and lobes were also fixed and analyzed micromorphologically, anatomically, and histochemically. The osmophores showed six markedly different distribution patterns that were not clearly associated with histological features. In most species, osmophores comprised papillose secretory epidermises and a few layers of subepidermal parenchyma. Starch grains, lipid droplets, and terpenes were detected in osmophores. An ornamented cuticle, cuticular folds, glandular and non-glandular trichomes, raised stomata and epicuticular wax granules are common traits in the species studied and may be useful in determining the taxonomy of the group. We found that 94% of the species visited by bees had papillose epidermises while the single hummingbird-pollinated species presented a flattened epidermis. Variations in osmophore pattern among species visited by bees, including variations within the same plant genus, are novel finding. Additionally, the Bignonieae species visited by bees presented a textured corolla surface, which has been reported as facilitating bee attachment and movement towards the floral resource. Future studies with a greater number of Bignonieae species and more detailed pollinator behavioral assays may help in the interpretation of the variations in corolla traits and functional relationships between flowers and pollinators.

Imidacloprid-induced mortality, histopathology and biochemical impairments in the larvae of oriental latrine fly (Chrysomya megacephala).

The concentration-mortality response of third instar larvae of Chrysomya megacephala (Diptera: Calliphoridae) to a synthetic insecticide, imidacloprid, and its impact on histopathological, histochemical, and biochemical parameters were determined in laboratory assays. Larvae displayed a concentration and time-dependent mortality response for the insecticide. Histopathological studies exhibited quite noticeable modifications in the epithelial cells, peritrophic membrane, basement membrane and muscular layer of the larval midgut. The ultrastructural analysis demonstrated alterations in nuclei, lipid spheres, microvilli, mitochondria, rough endoplasmic reticulum and lysosomes. In addition, histochemical tests on the midgut were performed, which revealed a strong reaction for proteins and carbohydrates in the control group and a weak reaction in the group exposed to imidacloprid in a dose and time-dependent manner. Imidacloprid also caused a significant reduction in the total midgut content of carbohydrates, proteins, lipids and cholesterol. Larvae treated with imidacloprid also showed a reduction in the activities of acid and alkaline phosphatases at all concentrations compared to untreated larvae.

Structural patterns of Lepidoptera galls and the case of Andescecidium parrai (Cecidosidae) galls on Schinus polygama (Anacardiaceae).

Gall anatomical and metabolic peculiarities are determined by the feeding habit of the gall inducer, but develop under the constraints of the host plants. The chewing habit of the Lepidoptera larvae imposes a high impact on the host plant cells, and supposedly drives peculiar structural and histochemical patterns. So, our starting point was the search of such patterns in literature, and the test of these traits on the Andescecidium parrai (Cecidosidae)-Schinus polygama (Anacardiaceae) system, as a case study in Chilean flora. The literature on the structure of lepidopteran galls in the temperate and tropical regions comprises 13 works, describing stems as the most frequent host organs, followed by leaves, buds, and flowers. As common structural traits of Lepidoptera galls, the literature converge in describing the processes of cell hypertrophy and hyperplasia, resulting in a variable number of common storage parenchyma layers, interspersed by the redifferentiated sclerenchyma, vascular, and typical nutritive cells around the larval chamber. These nutritive cells accumulate lipids and proteins, which support the lepidopteran larvae nutrition. As expected, the A. parrai galls follow the patterns herein described for the lepidoptera-induced galls, but with peculiarities associated with its host organ. Even though the Lepidoptera galls have destructive mouthparts and can induce large and complex galls, they cannot alter important conservative features of their hosts' organs.

Characterization of the Small Intestine in the Southern White-breasted Hedgehog (Erinaceus concolor) Using Histological, Histochemical, Immunohistochemical, and Scanning Electron Microscopic Techniques.

The present study was designed to investigate the microscopic features of the small intestine in the southern white-breasted hedgehog (Erinaceus concolor). The histochemical profile of the small intestine was investigated using periodic acid Schiff (PAS), alcian blue (AB, pH 2.5), and aldehyde fuchsin. The expression of SOX9 was also evaluated immunohistochemically, and the detailed morphology of intestinal mucosa was studied by using a scanning electron microscope. The intestinal wall was composed of the tunica mucosa, tunica submucosa, tunica muscularis, and tunica serosa. Plica circulares and muscularis mucosa were present only in the duodenum. The jejunal villi were the tallest and the ileal villi were the shortest. From the duodenum to the ileum, the population density of goblet cells decreased significantly. The goblet cells throughout the small intestine reacted positively with PAS and AB. The expression rate of SOX9 was not statistically different between the three parts of the small intestine (p > 0.05). In conclusion, despite the general characteristics of the small intestine in this species of hedgehog, there were some differences when compared with other mammalian and rodent species. These findings provide a baseline for future detailed research on the digestive system of the hedgehog species and other mammalian species.

Teucrium fruticans L., a Multi-Scale Study: From Trichomes to Essential Oil.

This work represents the first multi-scale study on Teucrium fruticans L. cultivated at the Ghirardi Botanic Garden (Lombardy, Northern Italy), combining a micromorphological and a phytochemical survey on the plant's aerial parts. Micromorphological investigations, performed by Light Microscopy, Fluorescence Microscopy and Scanning Electron Microscopy, highlighted the presence of five trichomes morphotypes, distinguished by a different distribution pattern: peltates, short-stalked and ball-like medium-stalked capitates, ubiquitous on the whole plant, medium-stalked and long-stalked capitates, exclusive to the floral whorls. Both peltates and medium-stalked capitates were recognized as the main terpene production sites. Phytochemical characterization focused on the essential oils (EOs), obtained by Clevenger-type hydrodistillation in February and April 2022 and characterized by Gas Chromatography-Mass Spectrometry (GC/MS), which resulted mainly formed by sesquiterpene hydrocarbons. The February EO profile was characterized by ß-caryophyllene (28.30 %) and germacrene D (19.16 %) as main compounds, while in April ß-myrcene was detected at high percentage (13.77 %), in addition to the previous two components (15.72 % and 11.55 %, respectively). Literature data, dealing with the biological activities of the main oil constituents, highlighted an anti-microbial, anti-inflammatory, and anti-tumor potential, due to the high content in sesquiterpenes and, particularly, of ß-caryophyllene and germacrene D.

Comparison of the Characteristics of Three Acellular Dermal Matrices Subjected to Distinct Processing Methods Using Five Types of Histochemical Staining.

BACKGROUND: Acellular dermal matrix (ADM) is treated using various devitalization and aseptic processing methods. The processing effects on ADM were evaluated by histochemical tests. METHODS: From January 2014 to December 2016, 18 patients [average age, 43.0 (range, 30-54) years] who underwent breast reconstruction with an ADM and tissue expander were prospectively enrolled. During the permanent implant replacement, a biopsy of the ADM was performed. We used three different human-derived products, namely, Alloderm®, Allomend®, and Megaderm®. Hematoxylin and eosin, CD68, CD3, CD31, and smooth muscle actin were used to evaluate the collagen structure, inflammation, angiogenesis, and myofibroblast infiltration. Each ADM was semi-quantitatively analyzed. RESULTS: Significant differences in collagen degradation, acute inflammation, and myofibroblast infiltration were observed among the ADMs. Collagen degeneration (p<0.001) and myofibroblast infiltration (smooth muscle actin-positive, p=0.018; CD31-negative, p=0.765) were the most severe in Megaderm®. Acute inflammation, represented by CD68, was most severe in Alloderm® (p=0.024). Both radiation and freeze-drying treatment physically damaged the collagen structure. Collagen degeneration was most severe in Megaderm®, followed by Allomend® and Alloderm®. Since Alloderm® is treated using chemicals, an assessment of the chemical irritation is warranted. CONCLUSIONS: The biopsy results were inconclusive. Therefore, to better interpret processing, more large-scale, serial, histochemical studies of each ADM are needed. LEVEL OF EVIDENCE IV: This journal requires that authors 38 assign a level of evidence to each article. For a full 39 description of these Evidence-Based Medicine ratings, 40 please refer to the Table of Contents or the online 41 Instructions to Authors www.springer.com/00266 .