Morphological studies concerning the digestive system can further information on animal diets, thus aiding in the understanding of feeding behavior. Given the scarcity of information on sea turtle digestive system morphology, the aim of the present study was to describe the digestive tube (DT) morphology of Eretmochelys imbricata hatchlings to further understand the diet of these individuals in the wild. DT samples from 10 stillborn turtles (undefined sex) were analyzed at the macro and microscopic levels. The esophagus, stomach, small intestine (SI), and large intestine (LI) are described. Histologically, the DT is formed by four tunics, the mucosa, submucosa, muscular, and adventitia or serosa. The esophagus is lined by keratinized stratified squamous epithelium, while the remainder of the DT is lined by a simple columnar epithelium. The esophagus mucosa is marked by conical, pointed papillae. The stomach comprises three regions, the cardiac, fundic, and pyloric and is covered by neutral mucous granular cells. The intestinal mucosa presents absorptive cells with microvilli, neutral and acidic goblet cells, and mucosa-associated lymphoid tissue. The SI is significantly longer than the LI (p value = 0.006841). These morphological findings are strong indications of adaptations to a carnivorous diet in this hawksbill turtle age group.

Hancornia speciosa Gomes is popularly known as mangabeira and occurs throughout Brazil. It belongs to the Apocynaceae family and is very important for its food and medicinal uses. The objective of this study was to perform the anatomical and histochemical characterization of the leaves of H. speciosa. Microscope slides were made containing cross sections of petiole and leaf blade, as well as paradermic sections of the leaf blade. The analyses were performed under light and polarized microscopy. For the histochemical analysis, different reagents were used, according to the targeted metabolite. Through microscopic analysis, it was possible to identify the anatomical structures that provide the detailed diagnosis of the studied species. Through histochemistry, the presence of phenolic compounds, tannins, alkaloids, triterpenes and steroids, lipophilic compounds, lignin, starch, and calcium oxalate crystals was evidenced in the leaf blade. Thus, the results presented contribute to the quality control of H. speciosa, as well as to bring unpublished data about the species and to increase knowledge about the Apocynaceae family.

Tramadol is used worldwide and is listed in many medical guidelines to treat both acute and chronic pains. There is a growing evidence of abuse of tramadol in some African and West Asian countries. Tramadol has some side effects. The present study designed to follow up the treatment of the cellular responses which might be induced in the kidney of tramadol mice. Treated mice received daily injection of tramadol dose (125 μg/100 g b.wt) for 20 and 40 days. Other mice received tramadol for 40 days and then were divided into three groups: the first received distilled water, the second received Lagenaria siceraria, and the third received melatonin daily for 40 days. Both the daily injection of tramadol for 20 and 40 days resulted in radical, extensive, and severe alterations in the normal histological architecture of the kidney. Treatment with Lagenaria siceraria or melatonin after tramadol administration for a long-term, markedly changed the collagen content and other chemical components, that may reach nearly normal levels. Such findings propose that although tramadol has many cytological and histopathological side effects on the kidneys of male mice, the treatments via Lagenaria siceraria and melatonin have effective therapeutic impacts on the tramadol side effects.

Suicidal behavior in termite workers is an extreme defensive strategy, probably a consequence of having a low number of soldiers available in the colony and there being high predation from enemies. We investigated the suicidal mechanism in workers of the Neotropical termite Neocapritermes opacus, which involves salivary gland autothysis followed by body cuticle rupture and the release of a defensive secretion. Autothysis was triggered by a physical stimulus such as a soldier bite that causes the protrusion of the salivary acini, burst reservoirs, and foregut. Histochemical and ultrastructural analyses showed salivary acini composed of peripheral parietal cells and two types of central cells, types I and II. Type I cells are filled with large electron-lucent secretory vesicles, which reacted positively to bromophenol blue and xylidine-Ponceau tests, indicating the occurrence of proteins. Type II cells are elongated and display smaller apical secretory vesicles. Parietal cells present an intracellular canaliculus with dense microvilli and cytoplasm rich in mitochondria and large electron-dense vesicles, which may participate in the self-destructive mechanism. Worker suicidal behavior was previously reported for N. taracua and N. braziliensis. N. opacus is a new species in which a salivary weapon has been developed and factors contributing to this altruistic response are discussed.

We describe the morphological adaptations of the tongue and gastrointestinal tract of the striped sand snake Psammophis sibilans and discuss their functional importance. Using standard histological, histochemical, and scanning electron microscopy techniques, we analyzed 11 adult snakes of both sexes. Our findings showed that the bifurcated non-papillate tongue exhibited chemoreceptive adaptions to squamate foraging behavior. The lingual apex tapered terminally with sensory spines, and the body of the tongue possesses a characteristic central odor–receptor chamber that might serve to trap and retain scent molecules. Furthermore, the intrinsic musculature showed interwoven and well-developed transverse, vertical and longitudinal muscle fibers that control contraction and retraction during probing and flicking. The esophagus displayed highly folded mucosa lined with columnar epithelium with goblet cells. In contrast, the stomach mucosa formed finger-like gastric rugae, encompassing tubular glands with dorsal gastric pits. The intestine is distinct from other vertebrates in lacking the crypts of Lieberkühn in the tunica mucosa and submucosa. The intestine mucosa is mostly arranged in interdigitating villi oriented perpendicular to the luminal surface. We extrapolated subtle variations for both acid and neutral mucopolysaccharides and glycoproteins localization as well as collagen fibers using histochemical analyses. The elaborate histo-morphological and functional adaptation of the tongue and digestive tract plays a pivotal role in foraging and feeding behavior.

Needles of Juniperus rigida are used in Chinese traditional medicine for the treatment of brucellosis, dropsy, skin disease, and rheumatoid arthritis. This is the first study that reports anatomical structures of the J. rigida needles collected at different altitudes. The most common anatomical, phytochemical, and histochemical techniques and methods are used. The results show that anatomical structures and chemical composition change significantly at different altitudes. The main anatomical characters are significant xeromorphic structures (thick epidermis, hypodermis, and cuticle), a stomatal band, a developed vascular bundle, and a marginal resin duct. The xeromorphic structures become more pronounced with increasing altitude. The phytochemical and histochemical results demonstrate that the content of the main chemical compounds (phenols and terpenoids) basically increases at a higher elevation. Histochemical analysis localizes the phenols in epidermal cells, sponge tissue, endothelial layer cells, and stomatal bands, and the terpenoids in palisade tissue, sponge tissue, and the edge of the resin duct. This work reveals the relation between anatomy and chemistry in J. rigida needles, contributes to the quality control of its ethno-medicine, and provides the evidence to develop the commercial cultivation.

The process of autophagy has been detected in the midgut epithelium of four millipede species: Julus scandinavius, Polyxenus lagurus, Archispirostreptus gigas, and Telodeinopus aoutii. It has been examined using transmission electron microscopy (TEM), which enabled differentiation of cells in the midgut epithelium, and some histochemical methods (light microscope and fluorescence microscope). While autophagy appeared in the cytoplasm of digestive, secretory, and regenerative cells in J. scandinavius and A. gigas, in the two other species, T. aoutii and P. lagurus, it was only detected in the digestive cells. Both types of macroautophagy, the selective and nonselective processes, are described using TEM. Phagophore formation appeared as the first step of autophagy. After its blind ends fusion, the autophagosomes were formed. The autophagosomes fused with lysosomes and were transformed into autolysosomes. As the final step of autophagy, the residual bodies were detected. Autophagic structures can be removed from the midgut epithelium via, e.g., atypical exocytosis. Additionally, in P. lagurus and J. scandinavius, it was observed as the neutralization of pathogens such as Rickettsia-like microorganisms. Autophagy and apoptosis ca be analyzed using TEM, while specific histochemical methods may confirm it.

Activity of brown and beige adipocytes could contribute to breed differences in fat deposition. Therefore, we compared the abundance of markers for adipocyte types in steers from three cattle breeds differing in fat deposition (Japanese Black, Holstein, Charolais). Markers for white (leptin (LEP)), beige (transmembrane protein 26 (TMEM26), uncoupling protein 1 (UCP1)), and brown adipocytes (Zic family member 1 (ZIC1), UCP1) were analysed by quantitative reverse transcription PCR in subcutaneous fat (SCF), intramuscular fat (IMF), intermuscular fat (IRMF), perirenal fat (PF) and visceral fat (VF). LEP messenger RNA (mRNA) was less abundant in VF compared with other depots (P<0.05). TMEM26 was weakly but evenly expressed in all depots in all animals, whereas UCP1 mRNA showed higher individual variation in some depots. ZIC1 was not detectable in VF and PF but abundant in SCF, IMF and even more abundant in IRMF (P<0.05). No significant breed differences were detected. Using antibodies against UCP1, TMEM26 and ZIC1, we demonstrated that fat depots of 26-month-old cattle still comprise different adipocyte types. However, our results did not support the hypothesis that higher energy expenditure associated with higher abundance or activity of beige or brown adipocytes contributed to differences in fat deposition.

This study examined bone tissue responses to Ti–6Al–4V alloy implants with a hard TiN coating applied by an original powder immersion reaction-assisted coating (PIRAC) nitriding method. Progression of implant fixation in the distal epiphysis and within the medullary cavity of the rat femur was evaluated between 3 days and 6 months postimplantation by scanning electron microscopy, oxytetracycline incorporation, and histochemistry. After 6 months, successful osseointegration was achieved in both epiphyseal and diaphyseal sites. Throughout, implant portions located within the epiphysis remained in close contact with bone trabeculae that gradually engulfed the implant forming a bone collar continuous with the trabecular network of the epiphysis. In the diaphysis, woven bone was first formed within the marrow cavity around the implant and later was replaced by a shell of compact bone around the implant. In general, higher osseointegration rates were measured for TiN-coated versus the uncoated implants, both in the epiphysis and in the diaphysis. In conclusion, our findings indicate an excellent long-term biocompatibility of TiN coatings applied by the PIRAC nitriding technique and superior osteoinductive ability in comparison with uncoated Ti–6Al–4V alloy. Such coatings can, therefore, be considered for improving the corrosion and wear resistance of titanium-based orthopedic implants.

As for many invertebrates, the gut of marine polychaete species has key physiological functions. However, studies integrating microanatomical descriptions with physiological processes are scarce. The present investigates histological, histochemical and cytological changes in the alimentary canal during the digestive cycle of the marine annelid Eulalia viridis, a species that combines opportunist scavenging, predation and cannibalistic behavior. The gut is comprised of an eversible pharynx, esophagus, intestine and rectum. Three main phases of digestion were identified, namely, resting/secretory, absorptive and excretory. The intestinal epithelium is complex and exhibited the most significant changes regarding intracellular digestion, excretion and storage. Conversely, the pharynx and esophagus were chiefly important for enzyme secretion. The results also indicate the existence of two distinct types of secretory cells in the intestine, with likely distinct physiological roles. Some similarities have been found between the intestinal epithelia and the molluscan (especially cephalopod) digestive gland, as, for instance, the shedding of apical corpuscles by digestive cells at posterior stages of digestion. The findings indicate that the digestive process in this worm is complex and related to the many physiological roles that cells need to play in the presence of reduced organ differentiation.

Degranulation of intestinal mast cells in rainbow trout was studied ex vivo by means of texture analysis and related to the maximal intestinal contraction elicited by degranulation itself. Two strips from the same intestinal segment from ten trout were sampled, processed for light microscopy and stained with Giemsa solution. One of the two strips was exposed to an incremental dose of compound 48/80 in an isolated organ bath before processing. Gray-level RGB channel equivalent and 8-bit gray-level images of five granular cytoplasm areas of mast cells for each section were analyzed for texture features and to evaluate discrimination possibility between treatment groups by means of linear discriminant analysis according to feature selection methods and RGB stacks. Differential mean values (after–before compound 48/80) of the green (r2 = 0.84, p < 0.01) and blue (r2 = 0.83, p < 0.01) RGB channels and 8-bit grayscale (r2 = 0.76, p < 0.05) image correlated significantly with the respective value of maximal intestinal contraction. A possible acidic (anionic) nature for the putative pro-contractile basophil agonist can be inferred.

This study presents the morphological description and histochemical characterization of gill filaments of the Brazilian endemic bivalve Diplodon expansus, aiming to broaden the morphological knowledge of this species and establish the structure of the gills that will serve as control in histopathological studies applied to biomonitoring. The gill filaments are divided into three zones: frontal, intermediate, and abfrontal. In the center of the filament, haemocytes circulate through the haemolymph vessel, which is internally lined by endothelium. The frontal surface of the filament is covered with cilia, the lateral surface exhibits aquifer ducts, and the abfrontal surface presents ciliated and nonciliated cells. The epithelium of the filaments is composed of ciliated cells, nonciliated absorptive cells, and mucocytes. The support of the filaments is made by two specialized structures called skeletal rod and skeletal loop. Based on the obtained information, the gill filaments of the studied species present some peculiar characteristics that are not yet reported in detail in the literature such as the simultaneous presence of skeletal rod and skeletal loop. On the other hand, the general constitution of the filament is similar to that described for both marine and limnic bivalves and seems to be suitable for ecotoxicological studies.

The final disposal of residues generated at sewage treatment plants (STPs) has become a major problem for cities, due to the increase in the amount of treated sewage. One of the alternatives for the residue, labeled “sewage sludge,” is its reuse in agriculture and in degraded soil. However, not all pathogens and metals present in it are eliminated during treatment. Diplopods have been used as bioindicators in ecotoxicological tests as they are constantly in close contact with the soil. Owing to this fact, the purpose of this study was to expose specimens of the diplopod Rhinocricus padbergi to substrate containing sewage sludge collected at STPs to analyze morphological alterations in their parietal and perivisceral fat body, where substances are stored. The exposures were held for 7, 15, or 90 days at different concentrations of sewage sludge (control, 1%, 10%, and 50%). The parietal fat body showed no alterations in any of the three exposure periods or concentrations. Alterations in the perivisceral fat body were observed for all exposure periods. According to the results, we suggest that the sludge used has toxic agents responsible for changing the animal's perivisceral fat body.

In this study the structure of collagen-chondroitin sulphate-hydroxyapatite porous composites is investigated by histochemical (Von Kossa staining), immunohistochemical, and transmission electron microscopy. Examination of composites on picrosirius red stained sections showed that polarization colors of collagen were generally in the range of orange-red. Immunofluorescence data indicate that chondroitin sulphate was either chemically incorporated into the bulk structure of collagen scaffolds or attached on surfaces of collagen bundles. Depending on the ratio between collagen:chondroitin sulphate:hydroxyapatite, von Kossa histochemical staining showed a progressive loading of collagen-chondroitin sulphate bundles with hydroxyapatite. Transmission electron microscopy studies have shown that composites contain mostly collagen fibrils aggregated with random orientation with very few collagen fibers showing the 67-nm banding pattern. Hydroxyapatite deposits of various sizes occurred among the collagen fibrils.

Comparative histochemical studies of glycosidase activity were carried out in Clonorchis sinensis, Eurytrema pancreaticum, Fasciola hepatica, Dipylidium caninum, Hymenolepis nana, Ascaris suum, Toxocara canis, Ancylostoma caninum, Trichuris vulpis and Dirofilaria immitis. The enzymes examined were: N-Acetyl-α-Glucosaminidase (Ec 3.2.1.30), α-Glucuronidase (Ec 3.2.1.31) and α-Galactosidase (Ec 3.2.1.23). There were variations in enzyme distribution and intensity among the species and also between trematodes and nematodes; no marked positive reaction for these enzymes occurred in cestodes. In some trematodes, the caeca, especially in the brush border, and the tegument, subtegumental cells and testes, were reactive to the enzymes. In nematodes, although there was variation in reactions among species, N-acetyl-α-glucosaminidase and α-galactosidase were localized in the hypodermis and lateral cords excluding the excretory canal, and coelomocytes, intestinal epithelium and the walls of the reproductive systems.

In 6 week-old Paramphistomum cervi, vitelline cells appear in the form of a few scattered cells, present below the body wall which divide mitotically to form vitelline follicles in 8 week-old worms. Small shell globules appear first in 10 week-old worms, the number and size of which continue to increase till the worm becomes adult. In the latter the vitelline follicles contain stem cells, immature, maturing and mature vitelline cells, which differ due to the distribution of shell globules as well as their histochemical nature. The shell globules are keratin in nature. The vitelline cells showed activities of various phosphatases but did not show the presence of any of the dehydrogenases studied.

The Chemical nature and mode of stabilization of the eggshell/capsule of Moniezia expansa, Avitellinalahorea and Stilesia globipunctata have been investigated using histochemical techniques. In M. expansa Where vitelline glands are present, the eggshell is stabilized by -S-S and -S-H linkages Whereas in A. lahorea and S. globipunctata, the viteline glands are absent and the double membranes, fibrous capsule and paruterine organ contain mainly elastokeratin-type structural protein. The possible role of the vitellaria in the presence or absence of eggshell and its thickness is discussed.

The formation of the egg mass in the ootype, containing the oocyte, vitelline cells, numerous spermatozoa and Mehlis’ gland secretion marks the beginning of eggshell formation. Mehlis’ gland cells pour their lipoprotein secretion into the ootype; this secretion forms a thin template around the egg mass and upon this template the shell globules are deposited. Eggshell formation begins in the proximal uterus and is completed in the middle uterus. The eggshells are devoid of phenols and phenolase indicating that hardening is not by quinone tanning. The eggshells contain keratin and are stabilized by disulphide linkages.

Mouse (C3H) mucosal glycoconjugates were examined in normal small intestines and intestines infected with Echinostoma caproni, or E. trivolvis using six different fluorescein-conjugated lectins: Triticum, vulgaris agglutinin (WGA), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin I (RCA-I). Glycine max soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), and Arachis hypogaeu peanut agglutinin (PNA). The expression of lectin-binding sites and the intensity of the binding of lectins in the mouse small intestines were changed by infection with the echinostomes. Specific differences in the reaction to glycoproteins were clearly observed between the mouse intestines infected with E. caproni and those infected with E. trivolvis. In E. caproni infection, binding of most of the lectins to the villi was remarkably reduced in accord with the villous atrophy and loss of goblet cells. In contrast, in E. trivolvis infection, the binding of WGA, RCA-I and DBA was reduced in the microvillar surfaces, but binding of UEA-I and SBA were unchanged compared to the control intestines. The lectin binding to goblet cells in E. trivolvis-infected mice mostly increased. These observations may reflect the marked increase in goblet cells and the less severe damage in the villi of E. trivolvis infection compared to E. caproni infection. Most of the glycoconjugates were slightly reduced in the hyperplastic crypts except for N-acetyl glucosamine. It is possible that glucose metabolism in the host intestines infected with E. trivolvis was activated. resulting in an increase in the rate of mucin synthesis as well as qualitative changes in mucus, thereby mediating the expulsion of the worms.