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Because of corneal transplantation limitations, there is a need for cornea-specific regenerative medicine. The development of such regenerative medicine has been delayed because of the complex and unique structure of the corneal stroma. Few studies have explored the corneal stroma cell distribution and cell types in vivo. This study investigated regional differences in morphological characteristics and distributions of corneal keratocytes and immunocompetent cells in the corneal stroma to clarify their functions and structural characteristics. The porcine eyeballs were subjected to light microscopy, transmission electron microscopy, scanning electron microscopy, and immunofluorescence staining analyses. Corneal cells were primarily located in the limbus, rather than the center of the cornea; the long keratocyte diameter was largest on the epithelial side of the corneal limbus, while the short diameter was largest on the endothelial side of the central cornea. Moreover, there were significantly more corneal cells on the epithelial side than on the endothelial side in both the central and limbus areas. Gap junctions between cells in the corneal stroma were present on the surfaces of cytoplasmic processes. Many cytoplasmic processes were scattered throughout the corneal stroma; they were connected both vertically and horizontally, forming an intercellular network. Additionally, immunocompetent cells on the epithelial side suggested to participate in this network via gap junctions. The morphology of keratocytes and immunocompetent cells on the epithelial side suggests that they play important roles in corneal homeostasis.

Adult T‐cell leukemia (ATL) is a mature T‐cell malignancy caused by human T‐cell leukemia virus type I infection, and 10%‐25% of patients show central nervous system (CNS) involvement. CNS involvement significantly reduces survival and there are no effective treatments for CNS involvement. Therefore, an appropriate animal model is required to evaluate the inhibitory effects of novel drugs on the progression of ATL with CNS involvement. Here, we established a mouse model of ATL with CNS involvement using NOD.Cg‐PrkdcscidIl2rgtm1Wjl/SzJ mice inoculated with ATL cells intramuscularly in the postauricular region, and these mice showed paraparesis. Of the 10 mice inoculated with ATL cells intramuscularly (I.M.) at 5 weeks of age, 8 (80%) showed paraparesis, whereas none of the 10 mice inoculated with ATL cells subcutaneously (S.C.) showed paraparesis. In the I.M. group, PCR detected HTLV‐1‐specific genes in the thoracic and lumbar vertebrae; however, in the S.C. group, the vertebrae were negative for HTLV‐1 genes. Histological analysis revealed a particularly high incidence of tumors, characterized by accumulation of the injected cells, in the thoracic vertebrae of mice in the I.M. group. Tumor cell infiltration was relatively high in the bone marrow. Spinal cord compression caused by invasion of the tumor mass outside the pia mater was observed in the thoracic vertebrae of the spinal cord. In conclusion, we have reported a mouse model of tumor growth with paraparesis that may be used to assess novel therapeutic agents for ATL with CNS involvement.

This study demonstrated the potential of using urea and urea fertilizer to neutralize formaldehyde (Fd) in chicken cadavers. Initially, in vitro Fd neutralization with various concentrations of urea solution (US) and urea fertilizer solution (UFS) was conducted; subsequently, 18% US and 27% UFS were selected for infusing into the formalinized chickens. The measurement at 48 hr after infusion showed that both solutions could effectively lower Fd in chicken cadavers to below a permissible exposure limit without affecting cadaveric and histological quality. In addition, neutralizing power of 18% US was approximately 1.3 times that of 27% UFS. This is the first demonstration of neutralizing potential of US and UFS against Fd both in vitro and in vivo.

Ehlers-Danlos syndrome (EDS) is a group of hereditary diseases caused by mutation of extracellular matrix-related genes. Recently, spondylodysplastic EDS-Zip13 (spEDS-Zip13: OMIM 612350) was recognized as a new EDS type. This current study could reveal various morphometric differences of collagenous population in the proper substance of cornea between the wild type and spEDS-Zip13-knockout (Zip13-KO) mice. Blockade of Smad-signaling pathway might initiate these alterations. Predilected dissimilarity in level of transcriptional activity probably dictated morphology of keratocyte and shape and electron density of its nucleus. In addition, the imbalance of proteoglycans and glycosaminoglycans would also affect the diameter and arrangement of collagen fibrils. These findings would be considered as vulnerable characteristics of corneal stroma of the Zip13-KO mice.

Superficial digital flexor tendon (SDFT) of the bovine hindlimb originates from the caudolateral aspect of the distal femur and finally inserts onto the plantar aspect of the middle phalanges. In the present study, morphology and morphometry of the bovine SDFT at the muscle-tendon junction (MTJ), middle metatarsus (mM) and tendon-bone interface (TBI) were investigated. Cross-sectional morphology at the three regions of SDFT were oval, semioval and ring-formed, respectively. Significant difference in cross-sectional area was found only between MTJ-mM and mM-TBI (P

Ingestion of collagen peptide (CP) elicits beneficial effects on the body, including improvement in blood lipid profiles, but the underlying mechanisms remain unclear. The purpose of this study was to investigate the effects of CP ingestion on the liver, which controls lipid metabolism in the body. Male BALB/cCrSlc mice were bred with the AIN-93M diet containing 14 % casein or the AIN-93M-based low-protein diet containing 10 % casein or a diet containing 6 % casein+4 % CP for 10 weeks (n 12/group). Total, free and esterified cholesterol levels in the blood decreased in the CP group. DNA microarray analysis of the liver revealed that expressions of genes related to lipid metabolic processes such as the PPAR signalling pathway and fatty acid metabolism increased in the CP group compared with the 10 % casein group. The expressions of several genes involved in steroid metabolic process, including Cyp7a1 and Cyp8b1, were decreased, despite being targets of transcriptional regulation by PPAR. These data suggest that lipid metabolism in the liver is altered by CP ingestion, and the decrease in blood cholesterol levels in the CP group is not due to enhancement of the steroid metabolic process. On the other hand, expressions of genes related to the unfolded protein response (UPR) significantly decreased at the mRNA level, suggesting that CP ingestion lowers endoplasmic reticulum stress. Indeed, protein levels of phosphorylated inositol-requiring enzyme 1 decreased after CP ingestion. Taken together, CP affects the broader pathways in the liver – not only lipid metabolism but also UPR.

The aim of this study was to determine the effects of prolyl-hydroxyproline (Pro-Hyp) on the proliferation and differentiation of rat stromal-vascular cells (SVCs) being cultured in a medium with (Pro-Hyp group) or without Pro-Hyp (control group). The results showed that there was no significant difference in proliferation rate of SVCs, lipid droplet (LD) diameter or intracellular concentration of triglycerides between two groups. However, the diameter range of LDs in the Pro-Hyp group tended to be smaller than that in the control group. Transmission electron microscopy showed a tendency for increase in the area of mitochondria and decrease in the number of mitochondria in the Pro-Hyp-treated SVCs. The mRNA expression levels of white adipose tissue differentiation markers (Cbp, Fabp and Serpina3k) were significantly lower, but those of the brown adipose tissue differentiation markers (Dio2, Ucp1 and Ucp3) were significantly higher in the Pro-Hyp group than in the control group. Our results suggested that Pro-Hyp can facilitate SVCs to differentiate into "brite/beige" adipocytes.

Zhen Qi Hypoglycemic Capsules (ZQHC) is a traditional Chinese herbal medicine containing medical activities by ougi (Astragalus membranaceus) and ousei (Polygonatum rhizome). Although ZQHC has been traditionally utilized as an anti-diabetic medicine in China, there is no evidence. Therefore, this study investigated the beneficial effects of ZQHC against diabetes using streptozotocin (STZ)-induced diabetic rats by biochemical and morphological methods. Eight-week old male Fisher strain rats were intraperitoneally injected with STZ (50 mg/kg of B.W.) to induce diabetes and were fed ad lib feeding with normal diet containing 4% ZQHC for 30 days. Blood and urine samples were collected for biochemical analysis, and liver and pancreas samples were prepared for morphological analysis. Values of blood glucose, AST and ALT of ZQHC oral administrated diabetic rats were lower than those of diabetic rats without administration. Morphological analysis revealed that ZQHC induced sustainment of insulin secreted β cells survival and suppression of hepatocellular fat droplet accumulation. These results suggested that oral administration of ZQHC has anti-diabetic activities those were mainly associated with improvement of liver metabolism.

Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities in the extracellular matrix (ECM). Transforming growth factor-β (TGF-β) plays a crucial role in formation of the ECM by the SMAD (Sma-and Mad-related protein, mothers against decapentaplegic homolog) pathway. It has been reported that loss of function of zinc transporter ZRT/IRT-like protein 13 (ZIP13) is the cause of the spondylocheiro dysplastic form of EDS (SCD-EDS: OMIM 612350). Our previous study suggested that TGF-β1 has a relationship with the skin pathological condition in the Zip13-Knockout (KO) mouse, which is a model of SCD-EDS. Thus far, effective treatment based on modern medicine for this syndrome has not yet been established. According to an approach of traditional Chinese medicine, the present study investigates the medicinal effects of Makomo (Zizania latifolia) on certain aspects of SCD-EDS, such as skin morphology and plasma TGF-β1, in Zip13-KO mice. Increases in densities of collagen fibers and fibrils without a significant change in thickness of the dermal layer were observed in the group of mice fed a Makomo-containing diet. No change in the amount of collagen suggests that Makomo feed does not elevate collagen synthesis, but changes the length of glycosaminoglycan chains and decreases the distance between collagen fibrils. In conclusion, the changes of the skin structure suggest that Makomo can increase the mechanical strength of skin.

The fine structures of different tendons in various animals at different ages have been studied extensively to reveal their arrangement and growth patterns. However, knowledge of the microstructures of the growing tenocytes in the tendons of piglets is still lacking. Thus, we performed the first morphometric analysis to describe the characteristics of tenocytes in the metacarpal superficial digital flexor tendon of 0-, 10- and 20-day-old piglets. In the present study, hydrochloric acid/collagenase digestion was applied to remove the interstitial connective tissue to obtain clear visualization of intact tenocytes and their cytoplasmic processes (Cp). Then, the morphometry of the tenocytes was investigated by optical and electron microscopy. The mean ± SE values of the fascicle area, number of tenocytes/fascicle, cell density, number of Cp/tenocyte, length of Cp, and thickness of Cp were compared among the three age groups. Significant differences (judged at P

In horse, the characterizations of hyalocytes under the steady state are still unclear. Therefore, we investigated characterizations of hyalocytes in normal equine eyes by their immunohistochemical phenotype, histomorphology and distribution. Thirty-one eyes from 18 horses, divided into 4 groups (G) by age, were used: early (G1) and late gestation (G2) fetuses, 1- to 3-year-old (G3) and 8- to 24-year-old (G4) horses. Equine hyalocytes were histologically classified into 4 types, and they immunohistochemically expressed MHC II and CD163. Hyalocytes were detected on and/or around ciliary processes and pars plana in G2, G3 and G4, but were not located on retina and optic papilla. A significant increase in distribution was found between G2 and both G3 and G4, and the largest distribution was found at ciliary processes in these groups. Equine hyalocytes were characterized as residential ocular macrophage and MHC II antigen-bearing cell, accompanied by a pleomorphic appearance and located in the contiguous ciliary body. Our data provided characterizations of hyalocytes in normal equine eyes and may well contribute to improving the understanding of pathogenesis of equine ocular disease.

Antigen-presenting cells (APCs) in the uveal tract participate in ocular immunity including immune homeostasis and the pathogenesis of uveitis. In horses, although uveitis is the most common ocular disorder, little is known about ocular immunity, such as the distribution of APCs. In this study, we investigated the distribution of CD163-positive and MHC II-positive cells in the normal equine uveal tract using an immunofluorescence technique. Eleven eyes from 10 Thoroughbred horses aged 1 to 24 years old were used. Indirect immunofluorescence was performed using the primary antibodies CD163, MHC class II (MHC II) and CD20. To demonstrate the site of their greatest distribution, positive cells were manually counted in 3 different parts of the uveal tract (ciliary body, iris and choroid), and their average number was assessed by statistical analysis. The distribution of pleomorphic CD163- and MHC II-expressed cells was detected throughout the equine uveal tract, but no CD20-expressed cells were detected. The statistical analysis demonstrated the distribution of CD163- and MHC II-positive cells focusing on the ciliary body. These results demonstrated that the ciliary body is the largest site of their distribution in the normal equine uveal tract, and the ciliary body is considered to play important roles in uveal and/or ocular immune homeostasis. The data provided in this study will help further understanding of equine ocular immunity in the normal state and might be beneficial for understanding of mechanisms of ocular disorders, such as equine uveitis.

Skeletal muscle is mainly composed of myofibers and intramuscular connective tissue. Bundles composed of many myofibers, with each myofiber sheathed in connective tissue called the endomysium, are packed in the perimysium, which occupies the vast bulk of the intramuscular connective tissue. The perimysium is a major determination factor for muscle texture. Some studies have reported that collagen peptide (Col-Pep) ingestion improves the connective tissue architecture, such as the tendon and dermis. The present study evaluated the effects of Col-Pep ingestion on the chicken iliotibialis lateralis (ITL) muscle. Chicks were allocated to three groups: the 0.15% or 0.3% Col-Pep groups and a control group. Col-Pep was administered by mixing in with commercial food. On day 49, the ITL muscles were analyzed by morphological observation and the textural property test. The width of the perimysium in the 0.3% Col-Pep group was significantly larger than other two groups. Although scanning electron microscopic observations did not reveal any differences in the architecture of the endomysium, elastic improvement of the ITL muscle was observed as suggested by an increase of the width of perimysium and improved rheological properties. Our results indicate that ingestion of Col-Pep improves the textural property of ITL muscle of chickens by changing structure of the perimysium.

Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities that are identified in the extracellular matrix. Transforming growth factor-β1 (TGF-β1) plays a crucial role in formation of the extracellular matrix. It has been reported that the loss of function of zinc transporter ZRT/IRT-like protein 13 (ZIP13) causes the spondylocheiro dysplastic form of EDS (SCD-EDS: OMIM 612350), in which dysregulation of the TGF-β1 signaling pathway is observed, although the relationship between the dermis abnormalities and peripheral TGF-β1 level has been unclear. We investigated the characteristics of the dermis of the Zip13-knockout (KO) mouse, an animal model for SCD-EDS. Both the ratio of dermatan sulfate (DS) in glycosaminoglycan (GAG) components and the amount of collagen were decreased, and there were very few collagen fibrils with diameters of more than 150 nm in Zip13-KO mice dermis. We also found that the TGF-β1 level was significantly higher in Zip13-KO mice serum. These results suggest that collagen synthesis and collagen fibril fusion might be impaired in Zip13-KO mice and that the possible decrease of decorin level by reduction of the DS ratio probably caused an increase of free TGF-β1 in Zip13-KO mice. In conclusion, skin fragility due to defective ZIP13 protein may be attributable to impaired extracellular matrix synthesis accompanied by abnormal peripheral TGF-β homeostasis.

Ultrastructural artifacts regarding collapse and aggregation of cultured cells have been problematic, especially when investigated apoptotic cells. The infiltration process during sample preparation is considered to be the most crucial factor for this problem. This study was conducted using two culture systems: a suspension culture system of human T-lymphocyte Jurkat cells and rabbit mature dendritic cells and a monolayer culture system of human lung macrophages, human breast cancer cells (A-546 cells) and cat bone-invasive gingival cancer cells (sccf3 cells). Fixation was conducted prior to removing or detaching the cells from the culture dishes. Initial infiltration with a 1 : 3 volume ratio of epon resin : propylene oxide was found to be the most crucial step among these cultured cells. The improved epon-resin infiltration method could eliminate the artifacts. Thus, differentiation between artifactual images and true images is highly possible.

In this study, we evaluated the effectiveness of isoprothiolane in preventing fatty liver in dairy cows. Eight pregnant Holstein cows with high body condition scores were studied. Four cows were administered isoprothiolane via feed at 10 g/day/head from 21 days before delivery (treated group), while the remaining four cows received no treatment (non-treated group). Liver samples from both groups were obtained 21 days before delivery and 2 days following delivery. No accumulation of lipid droplets in hepatocytes was observed in any cows prior to delivery. Following delivery, the accumulation of lipid droplets in hepatocytes was significantly reduced in the treated group compared to the non-treated group. The number of mitochondria per unit area was also significantly smaller in the treated group than in the non-treated group. Blood and biochemical test results from cows in the treated group showed an increase in mGOT levels and stable intrahepatic ATP production. These results suggest that isoprothiolane treatment intensified beta-oxidation in liver mitochondria, thereby activating the TCA cycle and maintaining intrahepatic ATP production.

Tendons are composed of collagen fibrils and proteoglycan predominantly consisting of decorin. Decorin is located on the d-band of collagen fibrils, and its glycosaminoglycan (GAG) chains have been observed between collagen fibrils with transmission electron microscopy. GAG chains have been proposed to interact with each other or with collagen fibrils, but its three-dimensional organization remains unclear. In this report, we used focused ion beam scanning electron microscopy to examine the three-dimensional organization of the GAG chain in the Achilles tendon of mature rats embedded in epoxy resin after staining with Cupromeronic blue, which specifically stains GAG chains. We used 250 serial back-scattered electron images of longitudinal sections with a 10-nm interval for reconstruction. Three-dimensional images revealed that GAG chains form a ring mesh-like structure with each ring surrounding a collagen fibril at the d-band and fusing with adjacent rings to form the planar network. This ring mesh model of GAG chains suggests that more than two GAG chains may interact with each other around collagen fibrils, which could provide new insights into the roles of GAG chains.

Beneficial effects of collagen peptide ingestion to reduce serum triacylglycerides have been reported, suggesting that the physiological conditions of adipocytes are modulated following collagen peptide inges- tion. In this study, the effects of prolylhydroxyproline, a major digestive product of ingested collagen pep- tide in the blood, on the differentiation of mouse 3T3-L1 preadipocytes in vitro were investigated. 3T3-L1 preadipocytes were induced to differentiate to adipocytes and treated with prolylhydroxyproline, or with an amino acid mixture of proline and hydroxyproline as a control. The amount of lipid was not affected by these treatments. However, the size of the lipid droplet was significantly smaller when treated with prolylhydroxyproline compared to the amino acid mixture or the non-treated control. Proton-coupled oligopeptide transporters were expressed in non-differentiated and/or differentiated 3T3-L1 cells. These results suggest that prolylhydroxyproline might modulate the morphology of lipid droplets by incorpora- tion into adipocytes through the transporters.

The equine superficial digital flexor tendon (SDFT) has a graded distribution of collagen fibril diameters, with predominantly small-diameter fibrils in the region of the myotendinous junction (MTJ), a gradual increase in large-diameter fibrils toward the osteotendinous junction (OTJ), and a mixture of small- and large-diameter fibrils in the middle metacarpal (MM) region. In this study, we investigated the ultrastructure of the SDFT, to correlate the spatial relationship of the collagen fibrils with the graded distribution. The surface-to-surface distances of pairs of fibrils were found to be almost constant over the entire tendon. However, the center-to-center distances varied according to fibril diameter. Decorin is the predominant proteoglycan in normal mature tendons, and has one dermatan sulfate (DS) or chondroitin sulfate (CS) filament as a side chain which is associated with the surfaces of the collagen fibrils via its core protein. We identified a coordinated arrangement of decorin DS filaments in the equine SDFT. The sizes of the decorin DS filaments detected by Cupromeronic blue staining showed a unique regional variation; they were shortest in the MM region and longer in the MTJ and OTJ regions, and a considerable number of filaments were arranged obliquely to adjacent collagen fibrils in the MTJ region. This regional variation of the filaments may be an adaptation to lubricate the interfibrillar space in response to local mechanical requirements. The results of this study suggest that the MTJ region, which receives the muscular contractile force first, acts as a buffer for mechanical forces in the equine SDFT.

The arrangement of collagen fibrils and glycosaminoglycans (GAGs) in substantia propria are important for maintaining transparency of the cornea. Interferences in collagen fibrils and GAG production could be adversative to corneal integrity. In this study, six dogs consisting of four Beagles with normal cornea (normal), one Beagles with opaque cornea (sample No. 1) and one Shih Tzu with neovascularization opaque cornea (sample No.2) were used. All samples were observed morphologically by light and electron microscopes to obtain diameter and distribution of collagen fibrils in substantia propria and were performed biochemically to investigate into GAGs and collagen types. The average diameter of collagen fibrils in the intact cornea of normal, sample No.1 and No.2 was 33.2, 35.0 and 25.0 nm, respectively. The percentage of matrix per unit area was 67% in normal, 87% in sample No.1 and 28.3% in sample No.2. The type III collagen ratio was 25.3% in normal, 21.3% in sample No.1 and 35.8% in sample No.2. The relative amount of heparan sulfate, chondroitin sulfate, dermatan sulfate and keratin sulfate was 1.5, 9.7, 51.1 and 37.7% in normal, 3.3, 26.0, 45.7 and 23.7% in sample No.1 and 1.2, 18.0, 16.6 and 54.1% in sample No.2. Hyaluronic acid was found only in sample No.1 with a relative amount of 1.3%. Since there was some relationship between collagen formation and GAGs composition, it might be speculated that disturbance in arrangement of collagen fibrils and GAG metabolism especially in substantia propria would bring up opacity of the cornea.

Epithelioid cells are found in lymph nodes in cases of metastatic carcinoma; however, epithelioid cells with benign features have also been discovered incidentally in lymph nodes. Epithelioid cells were observed in mediastinal lymph nodes of cattle without cancer during routine diagnostic necropsy. To explain this finding, the authors evaluated the prevalence and histopathologic, immunohistochemical, and ultrastructural features retrospectively using mediastinal lymph nodes from 110 cattle and found that 66 of the lymph nodes contained epithelioid cells. In all 66 nodes, most of the epithelioid cells were individual or aggregated in nodal sinuses; in 21 nodes, some epithelioid cells formed tubular structures. The individual and aggregated epithelioid cells were mostly considered to be mesothelial in origin by immunohistochemical and ultrastructural examination; presumably, they entered the lymph nodes via lymphatic vessels, because they were found in afferent lymphatic vessels and nodal sinuses. Although the presence of epithelioid cells in lymph nodes prompts suspicion of metastatic carcinoma, the epithelioid cells in these bovine lymph nodes did not disrupt nodal architecture, lacked atypia or mitotic figures, and did not invade nodal parenchyma.

Effects of the collagen oligopeptide (COP) were examined by its repeat injection into the inflammatory rabbit Achilles tendon (Tendo calcaneus communis), in which tenositis was induced by injection of bacterial collagenase. COP was evaluated 5 times over a period of 3 weeks to 1 month after injection of collagenase. At 1 month after treatment, the therapeutic effect of COP was evaluated by examining the structure of collagen fibrils, amount and components of glycosaminoglycans (GAGs) and matrix metalloproteinases (MMPs), and compared with the saline injection, control, and normal groups. The Achilles tendon of rabbit in the control group (no COP injection) and saline injection group showed a notable increase in the number of fine collagen fibrils, a change in GAG composition and increase in the amount of pro-MMP-2, indicating the weakening of the tendon. In contrast, the size distribution of collagen fibrils, GAG composition and the amount of pro-MMP-2 was similar to those in the normal group. These results suggest that COP injection promotes healing processes of the tendon injury.

The present study was carried out to determine the effect of decorin in the process of collagen assembly. Collagen fibrils were obtained in vitro by aggregation from commercialized acid-soluble type I collagen with the addition of different concentrations of decorin (0-25 microg/ml). All specimens were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The distribution of collagen fibril diameters was also analyzed by TEM. In samples without or with low concentrations of decorin, highly porous collagen fiber networks were formed. On the other hand, dense networks were observed in samples treated with high concentrations of decorin. The influence of decorin secreted by cells on collagen fibrils was observed by SEM, and the fiber network elasticity was measured using a rheometer. SEM images showed that collagen fiber networks without fibroblasts were much looser than those cultured with normal fibroblasts. The networks cultured with the fibroblasts were composed of straight fibers with large diameters. On the other hand, collagen fiber networks cultured with siRNA-decorin-transfected (siDT) fibroblasts had loose, meandering fibers with small diameters. The elasticity of collagen fiber networks cultured with untransfected fibroblasts showed no significant difference over the 7-day incubation period. However, significantly lower elastic values were obtained for collagen fiber networks treated with siDT cells on days 3 and 7. In addition, after treatment with 5.0 or 25 microg/ml decorin, the l collagen fiber networks cultured with siDT cells exhibited an altered structure that showed a dense structure similar to that of the fiber networks cultured with untransfected fibroblasts. In conclusion, this in vitro study showed that decorin is a regulatory and architecturally small leucine-rich repeat proteoglycan in the process of collagen fibril assembly.

Summary: The superficial digital flexor tendon (SDFT) is one of the longest tendons in the horse. In racehorses, disturbance of the locomotor functions of the SDFT occurs most frequently in the central area of the mid-metacarpal region. While many studies have investigated the equine SDFT, there are no reports to date of the morphological characteristics of collagen fibrils in the central and peripheral areas of each of the three regions that comprise the entire tendon: the myotendinous junction (MTJ), the mid-metacarpal region (mM) and the osteotendinous junction (OTJ). Mass average diameter (MAD), which provides functional information on the mean collagen fibril diameter and tensile strength of the tendon, was found to be smaller in the central area than in the peripheral area of all three regions. The MAD value was lowest in both the central and peripheral areas in the MTJ region, and tended to increase generally in a distal direction in the OTJ. The OTJ is important parts that unite with the bone. We conclude that morphological structure suggested that it corresponds to biomechanical function in some region of the equine SDFT.

Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities that are identified in the extracellular matrix. Transforming growth factor-β1 (TGF-β1) plays a crucial role in formation of the extracellular matrix. It has been reported that the loss of function of zinc transporter ZRT/IRT-like protein 13 (ZIP13) causes the spondylocheiro dysplastic form of EDS (SCD-EDS: OMIM 612350), in which dysregulation of the TGF-β1 signaling pathway is observed, although the relationship between the dermis abnormalities and peripheral TGF-β1 level has been unclear. We investigated the characteristics of the dermis of the Zip13-knockout (KO) mouse, an animal model for SCD-EDS. Both the ratio of dermatan sulfate (DS) in glycosaminoglycan (GAG) components and the amount of collagen were decreased, and there were very few collagen fibrils with diameters of more than 150 nm in Zip13-KO mice dermis. We also found that the TGF-β1 level was significantly higher in Zip13-KO mice serum. These results suggest that collagen synthesis and collagen fibril fusion might be impaired in Zip13-KO mice and that the possible decrease of decorin level by reduction of the DS ratio probably caused an increase of free TGF-β1 in Zip13-KO mice. In conclusion, skin fragility due to defective ZIP13 protein may be attributable to impaired extracellular matrix synthesis accompanied by abnormal peripheral TGF-β homeostasis.

In order to investigate the effects of collagen peptide ingestion on fibroblasts and the extracellular matrix in the dermis, collagen peptide was administered orally to pigs at 0.2 g/kg body weight/d for 62 d, and its effects were compared with those of lactalbumin and water controls. Fibroblast density, and diameter and density of collagen fibrils were significantly larger in the collagen peptide group than in the lactalbumin and water control groups. The two major components of dermal glycosaminoglycans, hyaluronic acid and dermatan sulfate, which are present in the inter-fibrillar space, did not differ significantly among the three groups. However, the ratio of dermatan sulfate, which is derived from fibril-bound decorin, was largest in the collagen peptide group. These results suggest that ingestion of collagen peptide induces increased fibroblast density and enhances formation of collagen fibrils in the dermis in a protein-specific manner.

The cruciate ligament and the collateral ligament play key roles in stabilization of the knee joint. Cases of serious knee joint problems presented at the, the Veterinary Teaching Hospital of Rakuno Gakuen University, Japan mostly involved rupture of the cranial cruciate ligament (CCL). Disorders in structural and biochemical components of the CCL were thought to be the causes of the knee problems. Morphological, biochemical and biomechanical features of the CCL and the lateral collateral ligament (LCL) were therefore analyzed. In the CCL, fibroblasts with ovoid and enlarged nuclei were observed mainly at the periphery of collagen bundles. The array of collagen fibrils in the LCL was slightly disoriented, but that of the CCL was tight and regular. In the LCL, the major groups of collagen fibrils were those with diameters of 70-80 and 120-130 nm. Most collagen fibrils in the CCL had diameters of 70-80 nm. The mean collagen diameters were 90 nm in the CCL and 105 nm in the LCL. The ratios of the noncollagen area to the area occupied by collagen fibrils were 43% in the CCL and 55% in the LCL. There was no difference between the amounts of HA or between the amounts of DS in two ligaments. However, the amount of CS in the CCL was about 17-times greater than that in the LCL. The expansion of and the resistance to tension exerted onto the CCL were less than those of the LCL. A high concentration of CS and low tensile strength due to small-sized collagen fibrils cause the CCL to rupture easily, especially when overextension of the knee joint occurs.

The aim of this study was to investigate alterations of cultured tendon tissues to determine whether tissue culture is a useful method for biological analyses of the tendon. Tendon tissues for tissue culture were isolated from Achilles tendons of rabbits. The tendon segments were placed one segment per well and incubated in growth medium consisting of Dullbecco's modified Eagle's medium supplemented with 5% fetal bovine serum at 37 degrees C in a humidified atmosphere with 5% CO(2) for various periods. The alignment of collagen fibrils was preserved for 48 h, but tendon structure has disintegrated at 96 h. Alcian blue staining and gelatine zymography revealed that proteoglycan markedly diminished and that matrix metalloproteinase (MMPs) activity was upregulated sharply at 72 and 96 h. The ratio of collagen fibrils with large diameter had increased and the mean diameter and mass average diameter value had reached maximum at 48 h. The values then decreased and mean diameters at 72 and 96 h were significantly different from that at 48 h. At 96 h, the ratio of collagen fibrils with small diameters had increased and collagen fibrils with large diameters had disappeared. These findings indicate that structural alteration is possible to be induced by disintegration of collagen fibrils and disappearance of glycosaminoglycans from extracellular matrix (ECM), subsequent of upregulation of MMPs activity. Although the study period is limited, the tissue culture method is available for investigating cell-ECM interaction in tendons.

The Golgi tendon organ (GTO) is an encapsulated fusiform mechanoreceptor siding in the musculo-tendinous junction of many animal species. Inhibitory function of afferent nerve fibers distributed from nearby motor units, the organ responds to active tension exerted onto the muscle. The morphological features of the equine GTO have not yet been elucidated. Additionally, there is some controversy regarding to the existence of the GTO in the equine superficial digital flexor tendon (SDFT). Therefore, immunohistochemistry and immunoelectron microscopy using alcian blue (pH 2.5) staining and the silver-enhanced colloidal gold method were carried out to determine both the location and characteristics of the GTO at the musculo-tendinous junction of the SDFT. A GTO with a fusiform structure of approximately 3 mm in length was found in the tendinous part. The lumen of the GTO was divided into compartments by septal cells. Each compartment contained collagen fibrils, nerve fibers and Schwann cells. This is the first report of the equine GTO.

A 30-month-old Holstein heifer presented with a history of decreased appetite and respiratory signs. Sonographic examination of the liver incidentally revealed an area of increased echogenicity between the portal vein and the gallbladder. The lesion was nonspherical and had no mass effect or displacement of the adjacent vessels. Its boundaries, to the liver, were geographic. The liver specimen was histologically compatible with a diagnosis of focal fatty liver change (FFLC). The sonographic features of focal fatty infiltration of the liver are characteristic. Recognition of the ultrasonographic data is important to differentiate FFLC from other lesions.

The ultrastructure of Sertoli cell in the testes of Korean native goats was investigated by scanning and transmission electron microscopy to elucidate the relationship between germ cell and Sertoli cell processes in the spermiogenetic cycle. Type-A Sertoli cells at stage V of the spermiogenetic cycle and type-B Sertoli cells at stage VII of the spermiogenetic cycle were used for analysis. Morphologically, the Sertoli cell processes were classified into sheet-like and slender cord-like processes. The sheet-like process originated solely from the Sertoli cell column while the slender cord-like process projected either from the Sertoli cell column or the sheet-like process. Periodic acid (PA)-thiocarbohydrazide (TCH)-silver protein (SP)-physical development (PD)-positive granules were found diffusively both in the sheet-like and slender cord-like processes near the round spermatid, whereas they had accumulated near the head of the elongated spermatid. The morphological variation and glucoconjugate histochemical reaction of the Sertoli cell processes reflect nourishment, movement and transformation of the spermatogenic cells in accordance with spermiogenesis.

The duodenal glands have been thought to play an important role in defense against proximal duodenal ulcer; however, the secretory mechanisms of these glands remain to be determined. In isolated duodenal acinar cells of the pig, we investigated the effects of ACh on intracellular Ca2+concentration ([Ca2+]i) and on membrane currents with fura 2 fluorometry and the patch clamp technique. ACh caused a transient increase in [Ca2+]i, and the increase was markedly inhibited by atropine or 4-diphenylacetoxy- N-methylpiperidine methiodide but not by hexamethonium, pirenzepine, or methoctramine. The expression of mRNA for the M3subtype far exceeded that for either M1or M2as revealed by real-time quantitative PCR and in situ hybridization. The rise in [Ca2+]ievoked by ACh was largely inhibited by thapsigargin but slightly affected by extracellular Ca2+deprivation. Caffeine had no effect on [Ca2+]i. ACh elicited Ca2+-dependent K+currents, a finding similar to the response to inositol 1,4,5,-trisphosphate applied intracellularly. These results suggest the presence of M3receptors linked to Ca2+release in porcine duodenal glands.

The distribution patterns of the intensity of negative charge on the free surfaces (glycocalyx of the plasma membrane) of endothelial cells (ECs) in blood vessels and reticular cells (RCs) in the splenic cord of the rat spleen were studied by an electron microscopic cytochemical method using polyethyleneimine (PEI) as a cationic probe. Spleens from adult male rats were perfusion-fixed with 0.5% glutaraldehyde -4% paraformaldehyde containing 0.05% cetylpyridinium chloride and then perfused with 0.5% PEI at pH 7.4. On the free surfaces (glycocalyx of the plasma membrane) of the ECs examined, distinct PEI-positive reactions were observed in blood vessels, such as trabecular arteries, central arteries, arterial capillaries, pulp veins and trabecular veins. These PEI-positive electron-dense substances in the trabecular arteries, central arteries, and trabecular veins took the shape of a band of 170-250 nm in thickness. On the other hand, the corresponding ultrastructure of the ECs lining the splenic sinuses and the RCs in the splenic cord showed exceedingly weak PEI reactions. The PEI-reactive deposits were significantly thinner than those in the above blood vessels. As the thickness of the electron-dense substances can be related to the density of the negative charge, these results suggest that there is a high intensity of negative charge on the free surfaces (glycocalyx of the plasma membrane) of ECs in blood vessels where blood cells and plasma pass into the red pulp or are discharged from the red pulp. In contrast, the splenic sinuses and RCs, which are the main components of the red pulp, contain weakly negative-charged sites. This may contribute to the microcirculation of the splenic blood vessels and elucidate the possible physiological functions of the spleen, such as blood storage.

The complex carbohydrates in the camel duodenal glands were examined histochemically at light and electron microscopic levels. The duodenal glands of the camel were distributed in the submucosa 2 m caudal from the pylorus. These were branched tubuloalveolar glands. The terminal portion of each lobule was formed by only one type of mucous cell. The duodenal gland cells contained acidic and neutral carbohydrates. The mucous cells mainly contained sulfate and carboxyl carbohydrate with sialic acid, and they also contained a few neutral carbohydrates with different saccharide residues such as mannose, glucose, galactose, N-acetyl glucosamine and N-acetyl galactosamine. The results showed that the secretary granules of the duodenal glands in the camel contain mainly acidic carbohydrates. These findings seem to be the morphological characteristics of the duodenal glands in the camel.

The fine structure in the center and periphery of the cornea of 16 beagle dogs were characterized and compared. The central cornea (about 540 microm) was apparently thinner than the peripheral cornea (about 720 microm). Thickness ratios of the corneal substantia propria to the entire cornea were approximately 86% in both portions. In addition, number of collagen lamellae, collagen fibril diameter, and collagen fibril index of the central substantia propria are different from those of the periphery (253 vs 236 lamellae, 29.1 vs 32.0 nm, and 39.0 vs 41.6%, respectively). These differences are thought to be due to site-dependent accumulation of proteoglycans (decorin and lumican) which are responsible for production of thin fibrils. The central portion with higher proteoglycans would have abundant thin fibrils with less slippage but better elasticity to buffer against the direct impact of intraocular pressure on the cornea. In contrast, thick fibrils in the peripheral substantia propria would contribute to the maintenance of tensile strength acting on the transition zone between the cornea and sclera.

A defect of the core protein of dermatan sulfate proteoglycan was suspected in a Holstein calf affected with a variant form of Ehlers-Danlos syndrome. The mutation was a guanine-to-adenine transition at nucleotide position 254, which resulted in a serine-to-asparagine substitution of the bovine proteoglycan core protein. This substitution occurred in the serine-glycine dipeptide repeat that was suspected to be the binding portion of dermatan sulfate. This point mutation in the genome was also detected by the use of restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) methods. The results of the RFLP and PCR indicated that the calf was a heterozygote of an abnormal gene and a normal gene of the core protein. The interpretation of these data revealed that the functional abnormality in cutaneous tissues of the calf was caused by an abnormal gene of the proteoglycan core protein, which induced a substitution of amino acid.

The distribution of endocrine cells and the areas of islets in the bovine pancreas were investigated by immunohistochemical methods. The islets in the A-region, which consisted of the left lobe, the ventral portion of the body, and the ventral and distal portions of the right lobe, contained a central core of insulin-containing (B-) cells surrounded by glucagon containing (A-) cells, a few somatostatin-containing (D-) cells and sporadic pancreatic polypeptide-containing (PP-) cells. The islets in the B-region, which consisted of the uncinate process, and the dorsal and proximal portions of the body and the right lobe, contained a central mass of B-cells, and peripheral cells which were predominantly PP-cells with a few D-cells but no A-cells. The areas of islets in the B-region were small as compared with those in the A-region. From these findings it is suggested that A- and PP-cells have a complementary relationship to one another. In view of this hypothesis, two types of islet, A-cell-rich and PP-cell-rich islets, were identified. The A-region contained A-cell-rich islets derived from the dorsal pancreatic primordium, while the B-region contained PP-cell-rich islets that originated from the ventral primordium. In the bovine pancreas, the areas containing PP-cell-rich islets are greater than those in previously examined species.

Immature B lymphocytes in the chicken bursa of Fabricius have previously been reported to undergo apoptosis by low doses of ionizing radiation. In the present study, newly hatched chickens were subjected to whole-body X-irradiation, and the bursa of Fabricius was examined at various postirradiation times by light and electron microscopy to obtain information on the change of ultrastructure of irradiated bursal cells as well as on the time course and dose-response for the induction of apoptosis. Histological examination by light microscopy showed that pyknotic cells started to increase in the bursa within a few hours after irradiation and the frequency of occurrence reached a maximum at 6 hr. An evident increase of the pyknotic cells in number was observed at a dose of as little as 1 Gy, and the frequency increased with increases in the dose, reaching over 90% at 15 Gy. Electron microscopy of the irradiated bursa revealed typical apoptotic morphology such as chromatin condensation, nuclear fragmentation, formation of apoptotic bodies and phagocytosis of pyknotic cells. Induction of apoptosis was also confirmed by the appearance of a typical DNA ladder pattern on agarose gel. Thus, the present results demonstrate that the chicken bursal cells are hypersensitive to X-irradiation with regard to induction of apoptosis, and that the apoptotic bursal cells exhibit most of the ultrastructural features known to be typical of apoptosis.

The microvasculature of bovine corpora lutea during pregnancy was studied by scanning electron microscopy using corrosion casts. Only one spiral arteriole branched directly from the ovarian artery entered the blood vascular bed of the pregnant corpora lutea. The bed consisted of numerous lobular sinusoidal capillary plexuses during pregnancy, and were characteristic to the microvasculature of a large corpus luteum. At the late stage of pregnancy, arteriovenous anastomoses were situated within the lobular sinusoidal capillary plexus composed of thin sinusoidal capillaries. These anastomoses may induce a decrease in blood flow to the lobular sinusoidal capillary plexus, suggesting that they may have an important role to induce the initial degeneration of the bovine pregnant corpora lutea.

Microvascular changes during the development of follicles in bovine ovaries were studied by scanning electron microscopy of corrosion casts. A clear vascular plexus of ovarian follicles appeared at the stage when secondary follicles were 200-400 microns in diameter. The plexus consisted initially of a thin, roughly structured and single-layered capillary network. During follicular development, the microvascular architecture of antral follicles was arranged as two independent vascular plexuses. The inner plexus, which received a spiral arteriole, consisted of a dense sinusoidal capillary network with an arterial and a venous layer; it functioned as an independent microcirculatory unit. The inner plexus developed from the capillary plexus of the theca interna of the secondary follicles. The outer plexus, which anastomosed with several stromal capillaries, consisted of a thin, coarse and basket-like capillary plexus. The outer plexus was formed from the stromal capillary plexus as a consequence of the rapid enlargement of developing antral follicles.