Feline leptospirosis prevalence worldwide: A systematic review and meta-analysis of diagnostic approaches.

Background and Aim: Leptospirosis in felids (domestic and wild cats) presents an ongoing challenge in our understanding. Numerous studies have reported the detection of Leptospira spp. in these feline populations, highlighting their potential as zoonotic carriers. This systematic review and meta-analysis aimed to provide insight into the global prevalence of leptospirosis in domestic and wild cats. Materials and Methods: We conducted extensive searches across five databases (PubMed, Scopus, Web of Science, Science Direct, and Google Scholar) following the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols guidelines. Random-effect meta-analyses were performed using R software version 4.3.0 to estimate pooled prevalence rates. Subgroup meta-analyses were conducted based on continents, diagnostic methods, sample types, and wildcat genera. Results: A total of 71 articles on leptospirosis in domestic cats and 23 articles on leptospirosis in wild cats met the eligibility criteria. Our findings indicated a significantly higher pooled seroprevalence of leptospirosis in domestic cats compared with infection prevalence (9.95% [95% confidence interval (CI), 7.60%-12.54%] vs. 4.62% [95% CI, 2.10%-7.83%], p = 0.01). In contrast, no significant difference was observed in pooled seroprevalence and infection prevalence among wild cats (13.38% [95% CI, 6.25%-21.93%] vs. 2.9% [95% CI, 0.00%-18.91%], p = 0.21). A subgroup meta-analysis of domestic cats revealed significant differences in seroprevalence across continents, sample types, and diagnostic methods. On the contrary, wild cats had no significant differences in any of the subgroups. Conclusion: Leptospira spp. have evidently been exposed to both domestic and wild cats, highlighting their potential roles as reservoir hosts for leptospirosis. These findings highlight the importance of considering felids as a possible public health threat.

Inflammatory responses to Opisthorchis viverrini infection in animal models: A comparison between susceptible and nonsusceptible hosts in different anatomical locations.

Background: Inflammation caused by Opisthorchis viverrini infection increases the risk of cholangitis, cholecystitis, and leads to bile duct cancer (cholangiocarcinoma or CCA). However, only certain infected individuals are susceptible to CCA, suggesting the involvement of host factors in cancer development. In addition, there are reports indicating differences in the locations of CCA. Aim: This study aims to investigate cellular inflammatory responses in the common bile duct (CB), intrahepatic bile duct (IHB), and gallbladder (GB) in susceptible and non-susceptible hosts following O. viverrini infection. Methods: Thirty Syrian golden hamsters (a susceptible host) and 30 BALB/c mice (a non-susceptible host) infected with O. viverrini were studied at six time points (five animals per group). Histopathological evaluations were conducted on samples from the IHB, CB, and GB. Inflammatory cell infiltration was quantitatively assessed and compared between groups and time points. Statistical analysis was performed using one-way ANOVA, with a significance level of p < 0.05. Results: Inflammation was significantly more pronounced in the IHB compared to the other two biliary locations. In comparison between susceptible and non-susceptible hosts, the intensity of inflammation was higher in the OV+H group than in the OV+M group (p < 0.05). Conclusion: This study highlights the association between host response to inflammation, tissue location, and host susceptibility, with the IHB showing particular susceptibility to inflammation and pathological changes. These findings contribute to our understanding of the increased risk of CCA in susceptible hosts.

Unraveling the relationship among inflammatory responses, oxidative damage, and host susceptibility to Opisthorchis viverrini infection: A comparative analysis in animal models.

Background and Aim: Opisthorchis viverrini infection-induced inflammation contributes to cholangiocarcinoma (CCA) development in humans and animals. Inflammation generates free radicals, such as reactive oxygen species and reactive nitrogen species (RNS), which damage the host's DNA. However, only 5% of O. viverrini-infected individuals develop malignancy, suggesting that variations in the inflammatory response of individuals to the parasite may influence susceptibility. Due to limitations in studying human susceptibility, we used an animal model to investigate the profiles of inflammatory reactions, oxidative burst, and irreversible DNA damage. This study aimed to explore the potential role of inflammation and RNS in causing DNA damage that may predispose susceptible hosts and non-susceptible animal models to cancer development in O. viverrini infection. Materials and Methods: This experimental study was conducted on 30 Syrian golden hamsters (OV-H) and 30 BALB/c mice (OV-M) infected with O. viverrini, representing susceptible and non-susceptible models, respectively. Five animals per group were examined at six predetermined time points during the experiment. Biliary tract samples were systematically investigated using histopathological evaluation for inflammatory cell infiltration and immunohistochemical staining for RNS production and markers of DNA damage, including nitrotyrosine and 8-hydroxy-2'-deoxyguanosine. These features were quantified and compared among the experimental groups. Mann-Whitney U-test was used for statistical analysis, with p < 0.05 considered statistically significant. Results: The comparison revealed that the OV-M group exhibited significantly earlier and higher rates of inflammatory cell infiltration during the acute phase, whereas the OV-H group exhibited chronic and more severe inflammation (p < 0.020). Intracellular RNS production and DNA damage were closely associated with the inflammatory response. Conclusion: This study demonstrates differential responses in susceptible and non-susceptible models of O. viverrini infection regarding disease onset and duration, as well as intracellular RNS production and DNA damage caused by inflammation. Persistent inflammation generated oxidatively damaged DNA, which is a distinct pathological characteristic of susceptible hosts and may be critical for CCA development.

Inflammatory cell responses in biliary mucosa during Opisthorchis viverrini infection: Insights into susceptibility differences among hosts.

Background: Individual host susceptibility is believed to be a risk factor in the interaction between the host and the parasite. Since studying time series in humans is limited, animal models are replaced. Aim: This study aims to explore and compare the pattern of inflammatory cell types along the biliary tract and their association with proliferative lesions in the early development of cholangiocarcinoma from susceptible and nonsusceptible animal models. Methods: Thirty male Syrian golden hamsters and 30 BALB/c mice, serving as the susceptible and nonsusceptible animal models, were used in this comparative study. The animals were infected with 50 Opisthorchis viverrini metacercariae via gastric intubation. At days 1, 2, 7, 14, 28, and 56 postinfection (p.i.), five animals were randomly selected from each group and humanely sacrificed. The hepatobiliary tissues were collected and processed for histopathological study. Histochemical and immunohistochemical staining were applied to differentiate the inflammatory cell types. Kruskal-Wallis and Mann-Whitney tests were applied to assess all semi-quantitative and quantitative variables. The correlation between each variable was also analyzed using Spearman rank at a p-value < 0.05. Results: The results demonstrated that mice had different patterns of infiltrating cell types when compared to hamsters. This suggested that the cellular response to the infection in mice occurred earlier than that in hamsters. The response in mice reached its peak at D7 to D14 and then rapidly declined at D28. In contrast, although the inflammatory response in hamsters started slowly, the response reached the peak at D28 and maintained a high level until D56. Significant differences in the number of inflammatory cells between mice and hamsters were seen at D1 (p = 0.047), D7 (p = 0.049), D28 (p = 0.040), and D56 (p < 0.040). Conclusion: The inflammatory responses to O. viverrini infection in the nonsusceptible animal model occurred and declined earlier while the response in the susceptible animal model occurred later in a gradual manner. Both rodents are suitable animal models for the studies of opisthorchiasis susceptibility.

Roaming behavior of the owned domestic cats (Felis catus) with possible roles in the transmission of Opisthorchis viverrini in the endemic area in Khon Kaen, Thailand.

In the endemic area of the liver fluke (Opisthorchis viverrini) infection, effective control of opisthorchiasis using One Health approaches requires transmission interruption in all hosts in the parasite life cycle. Owned domestic cats (Felis catus) are considered an important species among mammalian reservoirs. Similar to humans, household cats become infected by eating raw, contaminated fish and spread the O. viverrini eggs to the environment by defecation. In rural areas, cat owners usually feed their cats with human food or food waste, especially fish dishes. There is a high risk for cats to become infected and deposit eggs in the peri-household environment. The lack of research on domestic cats led us to study their roaming behavior, roaming range, habitat preference and risk of disease transmission. GPS loggers were harnessed to 28 domestic cats in 7 villages around Lawa Lake, the endemic area of human opisthorchiasis. All cats were examined for the O. viverrini infection status using modified formalin-ether concentration technique (MFECT) before application of the GPS device used to observe and record their roaming distance and range area. Then, composition analysis for habitat selection was performed using the location data. Additionally, cat owners were interviewed using participatory epidemiologic methods for their perceptions and knowledge about the reservoir hosts of this trematode. Our study suggested that the prevalence of O. viverrini in cats in this area has not declined appreciably in comparison with our previous study four years ago, although the treatment and control has been applied intensively in humans. The longest distance that individual cats roamed ranged from 51 to 363 meters (mean±SD = 154.48±90.71). The cats traveled tracks around their home. There was no significant difference in the average distance that cats ranged between O. viverrini infected group (154.13±72.80 meters) and the non-infected group (154.67±101.39 meters) was found. Compositional analysis suggested that the domestic cats preferred urban habitats where food and safety were probably more available. It appears that the main transmission route for infection of cats was contaminated fish fed to cats or fish that remained in their houses. Therefore, owners should refrain from feeding their cats potentially contaminated foods, food scraps and raw fish remains and prevent their cats from accessing them. Moreover, the participatory epidemiology results suggest that awareness of villagers is not enough for the effective and sustainable control of the disease.

Immunolocalization and functional analysis of Opisthorchis viverrini-M60-like-1 metallopeptidase in animal models.

Host mucins have crucial physical roles in preventing the parasitic establishment and maturation, and also in expelling the invading parasites. However, some parasites utilize mucinase enzymes to facilitate the infection. Recently, we have identified a mucinase enzyme of the liver fluke Opisthorchis viverrini, Ov-M60-like-1, which exhibits metallopeptidase activity against bovine submaxillary mucin substrate. Here, we aimed to study the localization of this enzyme in O. viverrini and the bile duct of hamsters using immunohistochemistry and functional analysis by mucin digestion in hamsters and mice tissues. The results showed that Ov-M60-like-1 was detected strongly in the tegument, tegumental cells, vitelline glands and mature eggs with miracidium. Expression in the gut, ovary and testis of the parasite was moderate while parenchyma showed slight colour intensity. In addition, the mucinase was also detected in the host biliary epithelial cells and goblet cells surrounding the worm. The mucinase assay revealed that the Ov-M60-like-1 could digest neutral mucin in the parenchyma, testis and seminal receptacle, but not the mucin in the tegument, tegumental cells and vitelline glands of the worm. The enzyme can also digest mucin in the cholangiocytes and modified the mixture type in the bile duct goblet cells of the infected hamsters, a susceptible host. In contrast, the enzyme was unable to digest neutral, acid and mixture mucin in the bile duct of the mice, a non-susceptible host. These findings indicate that Ov-M60-like-1 may have functions in both housekeeping tasks and host­parasite interactions, especially in modification of host susceptibility.

Investigation of possible alternate animal reservoir hosts of Opisthorchis viverrini.

Chronic opisthorchiasis caused by Opisthorchis viverrini (O. viverrini) adversely affects human health and is associated with a fatal bile duct cancer (cholangiocarcinoma). Although cats and dogs are known animal reservoir hosts of opisthorchiasis, there is limited information about whether other fish-eating animals are fluke reservoirs. Wetlands along Chi River of Thailand have abundant intermediate host snails and fish for O. viverrini and diverse other animal species. This led to our investigation into whether other fish-eating animals can also become infected and be alternate reservoir hosts for human opisthorchiasis. Our preliminary study focused on the O. viverrini infection status of crab-eating or long-tailed macaques roaming in Kosumpi National Forest Park in Chi River Basin, Kosumpisai District of Mahasarakam Province, and rodents, small residential mammals and fish-eating birds living in Lawa wetland complex of Khon Kaen Province. Fecal samples of each animal were collected and modified formalin ether concentration technique was applied to identify infections. Additionally, participatory epidemiology was used to retrieve information from local communities on opisthorchiasis transmission in these animals. No O. viverrini infection was found in any fecal samples suggesting that monkeys, rodents, small residential mammals and birds in these two wetlands probably do not serve as alternate reservoir hosts of O. viverrini.

Synergistic effects of cagA+ Helicobacter pylori co-infected with Opisthorchis viverrini on hepatobiliary pathology in hamsters.

Human liver fluke infection caused by Opisthorchis viverrini is associated with several biliary diseases including cholangiocarcinoma (CCA). Recently, it was discovered that the liver fluke is a reservoir of Helicobacter pylori, particularly the cagA-positive strain (cytotoxin-associated gene A) in its gut. Given that two carcinogenic pathogens are associated with CCA development, however, the role of cagA-positive H. pylori in opisthorchiasis has not been clarified. The present study was therefore aimed to investigate histopathological changes of the biliary system in hamsters co-infected with O. viverrini and cagA-positive H. pylori or O. viverrini and cagA-negative H. pylori, with controls of O. viverrini, cagA-positive H. pylori, or cagA-negative H. pylori alone, over time. Major histopathological changes were systematically investigated. All pathological features were quantified/semi-quantified and compared among the experimental groups. The results showed that O. viverrini infection groups (O. viverrini, cagA-positive H. pylori and cagA-negative H. pylori) showed a high degree of eosinophil and mononuclear cell infiltration, lymphoid aggregation and granuloma. Specifically, O. viverrini co-infected with cagA-positive H. pylori presented significantly higher inflammatory scores than O. viverrini and O. viverrini with cagA-positive H. pylori. Proliferation and adaptive lesions such as hyperplasia, goblet cell metaplasia and dysplasia were detected only in O. viverrini infection groups. Dysplasia, the precancerous lesion of CCA, was observed in the first-order bile ducts, especially where the inflammation existed and was found earlier and more severely in O. viverrini with cagA-positive H. pylori than other groups. Similarly, the BrdU (bromodeoxyuridine) proliferation index was significantly higher in O. viverrini co-infected with cagA-positive H. pylori than O. viverrini and O. viverrini with cagA-negative H. pylori groups. Periductal fibrosis was a prominent histopathologic feature in chronic infection in O. viverrini infection groups. Multiple logistic regression showed that O. viverrini co-infected with cagA-positive H. pylori and the duration of infection were the most important factors associated with periductal fibrosis (OR 3.02, 95% CI 1.02-9.29, p = 0.04 and OR 3.82, 95% CI 2.61-5.97, p<0.001). This study demonstrates that the liver fluke co-infected with cagA-positive H. pylori induces severe biliary pathology that may predispose to cholangiocarcinogenesis.

Three-dimensional ultrastructure reconstruction of tendinous components at the bifurcation of the bovine superficial digital flexor tendon using array and STEM tomographies.

Tendons transmit force from muscle to bone for joint movement. Tenocytes are a specialized type of fibroblast that produces collagen fibrils in tendons. Their cytoplasmic processes form a network surrounding collagen fibrils to define a collagen fibre. Glycosaminoglycan (GAG) chains link collagen fibrils and adhere at the D-band of the collagen fibril. In this study, we used array and scanning transmission electron microscope (STEM) tomographies to reconstruct the three-dimensional ultrastructure of tenocytes, collagen fibres, collagen fibrils and GAG chains at the bifurcation of the bovine hindlimb superficial digital flexor tendon (SDFT). Collagen fibrils comprising a collagen fibre were not aligned uniformly and had at least two running directions. Spindle-shaped tenocytes were arranged along the long axis of a plurality of collagen fibres, where two groups of collagen fibrils with oblique directions to each other exhibited an oblique overlap of the two collagen fibril layers. Collagen fibrils with different running directions were observed in separating layers of about 300 nm in thickness and had diameters of 0-200 nm. About 40% of all collagen fibrils had a peak in the range of 20-40 nm. STEM analysis of the same site where the crossing of collagen fibres was observed by transmission electron microscopy demonstrated the outline of collagen fibrils with a clear D-banding pattern at a regular interval. Collagen fibrils were reconstructed three-dimensionally using continuous images acquired by STEM tomography, which confirmed that the collagen fibrils at the crossing sites did not orientate in layers, but were woven one by one. Higher magnification observation of GAG chains attached between the crossing collagen fibrils revealed numerous GAG chains arranged either vertically or obliquely on collagen fibrils. Furthermore, GAG chains at the cross of collagen fibrils connected the closest D-bands. GAG chains are thought to be universally present between collagen fibrils of the tendon. These observations by array and STEM tomographies increase our knowledge of the anatomy in the bifurcation of the bovine hindlimb SDFT and demonstrate the utility of these new imaging technologies.

Ultrastructural study of the three-dimensional tenocyte network in newly hatched chick Achilles tendons using serial block face-scanning electron microscopy.

The lateral cytoplasmic processes of tenocytes extend to form three-dimensional network surrounding collagen fibers. It is unknown whether connections between two cytoplasmic processes involve overlapping of the processes or merely surface contact. In this study, the two-dimensional and three-dimensional structure of tenocytes in the Achilles tendons of the newly hatched chicks were studied using transmission electron microscopy and serial block face-scanning electron microscopy. Observation of the two-dimensional structures revealed various forms of cellular connections, including connections between the cytoplasmic processes of adjacent tenocytes and between the cytoplasmic process of tenocytes and fibroblasts. Three-dimensional observation showed spike-like cytoplasmic processes extending from one tenocyte that interlocked with cytoplasmic processes from other tenocytes. Cytoplasmic processes from each tenocyte within the chick tendons interlocked to ensure a tight cell-to-cell connection around growing collagen fibers. A cellular network formed by these cytoplasmic processes surrounds each collagen fiber. Cell-cell junctions, which were suggested to be gap junctions, observed at sites of cytoplasmic process overlap most likely represent the major route for communication between tenocytes associated with fibroblasts, enabling vital signals important for maintaining the cell and tendon integrity to be transmitted.

Morphometric analysis of thoracic aorta in Slc39a13/Zip13-KO mice.

Ehlers-Danlos syndrome (EDS) is a collection of inheritable diseases involving the musculoskeletal, integumentary and visual systems. Spondylodysplastic EDS-ZIP13 (spEDS-ZIP13: OMIM 612350) was recently defined as a new form of EDS. Although vasculitis has been found in many spEDS-ZIP13 patients, vascular pathology has not been included as a pathognomonic lesion of this type of EDS. We investigate the morphometry of the thoracic aorta in wild-type and Zip13-knockout (Zip13-KO) mice. Our assessment found abnormalities in the number and morphology of elastic and cellular components in the aortic wall, especially the tunica media, of Zip13-KO mice, indicating aortic fragility. Accordingly, our major findings (vascular smooth muscle cells with small nuclei, small percentage of elastic membrane area per tunica media, many large elastic flaps) should be considered vulnerable characteristics indicating fragility of the aorta in patients with spEDS-ZIP13.

Structural alteration of glycosaminoglycan side chains and spatial disorganization of collagen networks in the skin of patients with mcEDS-CHST14.

Musculocontractural Ehlers-Danlos syndrome (mcEDS) due to CHST14/D4ST1 deficiency (mcEDS-CHST14) is a recently delineated type of EDS caused by biallelic loss-of-function mutations in CHST14, which results in the depletion of dermatan sulfate (DS). Clinical characteristics of mcEDS-CHST14 consist of multiple malformations and progressive fragility-related manifestations, including skin hyperextensibility and fragility. Skin fragility is suspected to result from the impaired assembly of collagen fibrils caused by alteration of the glycosaminoglycan (GAG) chain of decorin-proteoglycan (PG) from DS to chondroitin sulfate (CS). This systematic investigation of the skin pathology of patients with mcEDS-CHST14 comprised both immunostaining of decorin and transmission electron microscopy-based cupromeronic blue staining to visualize GAG chains. Collagen fibrils were dispersed in the affected papillary to reticular dermis; in contrast, they were regularly and tightly assembled in controls. Moreover, the fibrils exhibited a perpendicular arrangement to the affected epidermis, whereas fibrils were parallel to control epidermis. Affected GAG chains were linear, stretching from the outer surface of collagen fibrils to adjacent fibrils; in contrast, those of controls were curved, maintaining close contact with attached collagen fibrils. This is the first observation of compositional alteration, from DS to CS, of GAG side chains, which caused structural alteration of GAG side chains and resulted in spatial disorganization of collagen networks; this presumably disrupted the ring-mesh structure of GAG side chains surrounding collagen fibrils. McEDS-CHST14 provides a critical example of the importance of DS in GAG side chains of decorin-PG during assembly of collagen fibrils in maintenance of connective tissues.

Reservoir Animals and Their Roles in Transmission of Opisthorchis viverrini.

Although any fish-eating mammals could be potential definitive hosts of Opisthorchis viverrini, only a few, especially cats and dogs, are actually known reservoir hosts for this parasite. Both animals usually get infected via consuming raw or undercooked contaminated fish, fish dishes or food remains from households. The infected animals sustain parasite egg spread via open environment defecation. Cats are the most important reservoir with higher prevalence rates of O. viverrini infection than dogs in endemic areas. Usually Opisthorchis-infected animals do not exhibit apparent clinical symptoms or specific abnormalities in laboratory examinations. Pathological findings in these animal reservoirs are basically similar to those seen in humans and experimental animals, namely periductal inflammation, biliary hyperplasia and periductal fibrosis. However, O. viverrini-associated cholangiocarcinoma has not yet been reported in the reservoir animals at present. Praziquantel is a treatment of choice not only for humans but also for animal reservoirs. Integrated control of opisthorchiasis in animal reservoirs is based on holistic approaches such as EcoHealth/One Health concepts. In fact integrated control of opisthorchiasis in humans in ecosystem has also proved successful, for example, the Lawa model for opisthorchiasis control in the endemic area of Khon Kaen, Thailand. Other feral and wild animals in endemic areas might also be potential reservoirs, and this requires more investigation. In addition, genetic diversity and evolution of the flukes might also influence zoonotic capability.

Morphometric analysis of cornea in the Slc39a13/Zip13-knockout mice.

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.

Neutralizing formaldehyde in chicken cadaver with urea and urea fertilizer solution.

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.

Fibrillar architecture at three different sites of the bovine superficial digital flexor tendon.

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<0.05). Functional compression and friction from the adjacent structures could be the most potential interactions affecting such appearances. Morphometric data of tenocyte number, water content, and glycosaminoglycan (GAG) length and angle were found increasing in the proximodistal direction, except the fibril diameter and collagen fibril index (CFI). Statistical analyzes could reveal significant differences in average number of tenocytes (P<0.0001), CFI (between MTJ-mM and MTJ-TBI, P<0.05), water content (between MTJ-TBI, P<0.05), length of GAG chains (between MTJ-TBI, P<0.05), and angle of GAG chains (P<0.0001), respectively. The fibrillar characteristics at the three different areas, including fibril diameter distribution and interfibrillar distance, existed in conforming to the tensional axes in situ. In addition, length and angle of GAG chains were relevant to moving directions of the collagen fibrils.

Morphometric analysis of growing tenocytes in the superficial digital flexor tendon of piglets.

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<0.05) were found in almost all morphometric aspects among the age groups, except for the number of Cp/cell (P=0.545) and thickness of the Cp (P=0.105). A decrease of cell density corresponded with an increase in the length of the Cp, which were extended to connect either with the Cp of the other tenocytes or the surrounding endotendineum. Moreover, an increase of the fascicle area reflected the increase in tendon diameter. The revealed morphometric characteristics are thus the outcome of tendon growth.

Changes in skin structure of the Zip13-KO mouse by Makomo (Zizania latifolia) feeding.

Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities in the extracellular matrix (ECM). Transforming growth factor-ß (TGF-ß) 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-ß1 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-ß1, 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.

Efficacious and safe dose of praziquantel for the successful treatment of feline reservoir hosts with opisthorchiasis.

Opisthorchiasis caused by Opisthorchis viverrini is a major food-borne zoonosis in Greater Mekong sub-region. Even though campaigns discouraging the consumption of raw fish have been launched to public, the disease still remains highly endemic. The unsuccessful eradication of the disease is probably because of the persistence of the parasite in animal reservoir hosts, particularly felids. Praziquantel (PZQ) is the drug of choice for morbidity control of opisthorchiasis in humans and animals. However, there is no specific study on its dosage regimen for feline opisthorchiasis. Thus, the effective treatment dose of PZQ, as well as its adverse effects, was evaluated in O. viverrini infected cats. Twenty-eight infected male and female cats from the endemic area of Khon Kaen and Maha Sarakham Provinces, Thailand were enrolled in this study. Physical, hematological, blood chemical and urine examinations were analyzed, as indicators of health status, on the day before and 30days after treatment. Intensity of the infections was determined by the formalin-ethyl acetate sedimentation technique. Cats were equally allotted into the low infection group of 14 cats with egg count per gram of feces (EPG) <300 and the high infection group of 14 cats with EPG higher than 300. Cats in each group were equally divided into two subgroups of 7 cats; thus, there were two low infection subgroups (L1 and L2 subgroups) and two high infection subgroups (H1 and H2 subgroups). A single dose of 25mg/kg PZQ was orally administered to each cat in the L1 and H1 subgroups and a single oral dose of 40mg/kg PZQ was administered to the L2 and H2 subgroups. Complete clearance of O. viverrini eggs was found in all cats in the L1, L2 and H2 subgroups; thus, the cure rate (CR) and egg reduction rate (ERR) were 100%. However, partial clearance was observed in two cats with high EPG (1502 and 1518) in the H1 subgroup, which received 25mg/kg PZQ. Regards, CR and ERR for these two animals was 71.4 and 99.5%. No significant difference among the 4 subgroups was seen. Almost all hematological, blood chemical and urinalysis data were within normal ranges, except for the eosinophilia and an increase of alanine aminotransferase (ALT). Hookworm infection seen in all cats would cause eosinophilia. As for drug safety, there was no side effect observed in any cats. In conclusion, this study suggested that 40mg/kg PZQ is a highly effective and safe dosage for the treatment of feline reservoir hosts of human opisthorchiasis.

Decreased risk of cholangiocarcinogenesis following repeated cycles of Opisthorchis viverrini infection-praziquantel treatment: Magnetic Resonance Imaging (MRI) and histopathological study in a hamster model.

It has been suggested that repeated infection of Opisthorchis viverrini followed by repeated treatment with praziquantel (PZQ) increases risk of development of cholangiocarcinoma (CCA). Evidence for the prediction has accumulated based on findings of indirect approaches involving molecular changes and epidemiological trends. By contrast, here we directly monitored the impact of repeated liver fluke infection and treatment with PZQ on cholangiocarcinogenesis in a rodent model of human opisthorchiasis, using magnetic resonance imaging (MRI) and histopathology. Twenty five Syrian golden hamsters were assigned to five treatment groups: 1) infection with O. viverrini (OV group), 2) treatment with the carcinogen N-nitrosodimethylamine (NDMA) at 12.5ppm (DMN), 3) O. viverrini infection in tandem with NDMA (OD), 4) O. viverrini infection, NDMA, and treatment with PZQ (ODP), and 5) uninfected, untreated control. The repeated infections were established by intragastric inoculation of 50 metacercariae of O. viverrini to the OV, OD and ODP hamsters at weeks 0, 5 and 10. PZQ at 300mg/kg body weight was given to each hamster of the ODP group on weeks 4, 9 and 13 (four weeks after each infection). Imaging by MRI was undertaken on weeks 5, 10 and 14 (i.e. one week after each PZQ treatment). MRI revealed that the ODP hamsters did not develop CCA, whereas necropsy at week 40 revealed CCA in hamsters of the OD and DMN groups. Findings for histopathology and for proliferating cell nuclear antigen index conformed to the MRI findings. In overview, and notwithstanding that the immune response of individual hosts may play roles in cholangiocarcinogenesis, three cycles of the infection with O. viverrini followed treatment of the infection with PZQ did not increase the risk of bile duct cancer in this hamster model of liver fluke infection-induced CCA.