Review of animal mycoses in Australia

This review covers the available literature on the mycoses of animals in Australia since the last review published in 1967. Of the cutaneous infections, dermatophytoses have been recorded in a wide range of animals: cattle, horses, goats, pigs, sheep, cats, dogs, mice, guinea-pigs, rabbits, a lion, kangaroos, a camel, koalas and wallabies. These infections were caused by several species and varieties of the genera,Microsporum andTrichophyton. Eight agents of ringworms have been recorded in the horse. Two subcutaneous mycoses, phaeohyphomycosis and sporotrichosis have been reported. Phaeohyphomycosis is becoming more common but sporotrichosis is rare having been recorded only once in a cat.The following systemic mycoses have been recorded: adiaspiromycosis, aspergillosis, candidiasis, cryptococcosis, dactylariosis, fusariomycosis, histoplasmosis, miscellaneous mycoses, mycotic abortion and related conditions, zygomycosis, pythiosis, protothecosis and green algal infections. Cryptococcosis has affected 11 different animal species. Mycotic abortion is a serious disease in Victoria. Pythiosis of horses has been extensively studied in northern Australia.     

Human Pythiosis: Emergence of Fungal-Like Organism

Pythiosis is an emerging infectious disease caused by the aquatic oomycete Pythium insidiosum, a fungal-like organism. It is believed that P. insidiosum’s zoospores, its infected form, play major role in pathogenesis. Vascular and ocular infections are the most common clinical manifestation in humans. It is difficult to establish the diagnosis given its relatively rarity and difficulty to distinguish P. insidiosum from other molds. Delay in diagnosis and treatment has been associated with poor outcomes. High index of suspicion is the key, particularly in thalassemia patients with arterial insufficiency and patients with fungal keratitis/endophthalmitis without improvement on antifungal therapy. Tissue culture and zoospore induction remain gold standard for diagnosis; however, DNA-based method should be performed simultaneously. The combination of radical surgery, antifungal agents, and immunotherapy has been recommended. It was previously believed that surgery with negative surgical margins was the essential to survive in vascular pythiosis; however, it was recently found that patients could have residual disease despite documented negative surgical margins as infected clot may be dislodged to proximal arterial sites prior to surgery. Serum β-d-glucan (BG) has been used to monitor disease response after treatment initiation in vascular pythiosis. A significant decrease in BG levels within 2 weeks after surgery is indicative of the absence of residual infection. Unfortunately, monitoring tools for ocular pythiosis are not yet available. Itraconazole plus terbinafine have generally been used in P. insidiosum-infected patients; however, antibacterial agents, including azithromycin and linezolid, have also been used with favorable outcomes in ocular disease. Recently, azithromycin or clarithromycin plus doxycyclin were used in two relapsed vascular pythiosis patients with good outcomes.

     

CYFRA21-1、MMP-3及CEA 和细胞学联合检查对恶性胸腔积液的诊断价值分析

摘要 目的：探讨细胞角蛋白19片段（CYFRA21-1）、基质金属蛋白酶-3（MMP-3）及癌胚抗原（CEA） 和细胞学联合检查对恶性胸腔积液的诊断价值。方法：选择2020年1月至2023年1月我院接诊的100例胸腔积液患者进行研究,并根据病理结果分为实验组47例（病理检查结果恶性）,对照组53例（病理检查结果良性）,分析血清CYFRA21-1、MMP-3及CEA 和细胞学水平变化情况及其的诊断价值。结果：实验组患者血清血清CYFRA21-1、MMP-3及CEA水平显著高于对照组,差异显著（P＜0.05）;实验组患者CYFRA21-1、MMP-3及CEA 和细胞学阳性率均显著高于对照组,差异显著（P＜0.05）;CYFRA21-1诊断恶性胸腔积液的AUC为0.989,95%CI为0.977~1.000;MMP-3诊断恶性胸腔积液的AUC为0.979,95%CI为0.964~0.994;CEA 诊断恶性胸腔积液的AUC为0.982,95%CI为0.967~0.997;细胞学诊断恶性胸腔积液的AUC为0.823,95%CI为0.766~0.879,联合检测时AUC为0.995,95%CI为0.990~1.000,较单独检测曲线下面积比较显著差异;且特异度、准确度均较单独检测更高。结论：CYFRA21-1、MMP-3及CEA 和细胞学联合检查可有效提高诊断恶性胸腔积液的准确性,临床应用价值高。     

Thyroid Tuberculosis With Abnormal Thyroid Function-Case Report And Review Of The Literature

ObjectiveTo report an extremely rare case of thyroid tuberculosis (TT) with abnormal thyroid function and to review the related literature.MethodsWe present the patient's history, clinical findings, laboratory test results, imaging examinations, cytological data, management, and follow-up. In addition, we perform a review of the previously published cases of TT and give special attention to those with hypothyroidism.ResultsA 45-year-old Indian man presented to the outpatient clinic with neck swelling and respiratory and constitutional symptoms. Cervical ultrasound revealed a thyroid nodule and a necrotic right cervical adenopathy. Fine-needle aspiration cytology (FNAC) was performed and purulent material was removed from thyroid and lymph node. In both specimens, the culture was positive for Mycobacterium tuberculosis complex, and a cytological examination revealed epithelioid cell granulomas and necrosis. Mycobacterium tuberculosis complex was also identified by sputum culture. Antibiotic testing revealed sensitivity to all first-line drugs. A diagnosis of disseminated tuberculosis with thyroid and cervical lymph node involvement was made. Thyroid function was consistent with subclinical hyperthyroidism that subsequently evolved to hypothyroidism, requiring thyroid hormone replacement, and reflected tuberculous thyroiditis. Anti-tuberculosis drugs were started with good therapeutic response.ConclusionTT is a rare condition and its association with thyroid function abnormalities is even rarer. To our knowledge this is the third report of hypothyroidism related to TT and the first to identify a period of hyperthyroidism preceding hypothyroidism. Despite its rarity, TT should be considered in the differential diagnosis of neck mass. FNAC is a useful procedure and thyroid function should be monitored.     

Pythium insidiosum complex hides a cryptic novel species: Pythium periculosum

Early phylogenetic analysis of Pythium insidiosum, the etiologic agent of pythiosis in mammals, showed the presence of a complex comprising three monophyletic clusters. Two included isolates recovered from cases of pythiosis in the Americas (Cluster I) and Asia (Cluster II), whereas the third cluster included four diverged isolates three from humans in Thailand and the USA, and one isolate from a USA spectacled bear (Cluster III). Thereafter, several phylogenetic analyses confirmed the presence of at least three monophyletic clusters, with most isolates placed in clusters I and II. Recent phylogenetic analyses using isolates from environmental sources and from human cases in India, Spain, Thailand, and dogs in the USA, however, showed the presence of two monophyletic groups each holding two sub-clusters. These studies revealed that P. insidiosum possesses different phylogenetic patterns to that described by early investigators. In this study, phylogenetic, population genetic and protein MALDI-TOF analyses of the P. insidiosum isolates in our culture collection, as well as those available in the database, showed members in the proposed cluster III and IV are phylogenetically different from that in clusters I and II. Our analyses of the complex showed a novel group holding two sub-clusters the USA (Cluster III) and the other from different world regions (Cluster IV). The data showed the original P. insidiosum cluster III is a cryptic novel species, now identified as P. periculosum. The finding of a novel species within P. insidiosum complex has direct implications in the epidemiology, diagnosis, and management of pythiosis in mammalian hosts.     

Immune response dynamics and Lutzomyia longipalpis exposure characterize a biosignature of visceral leishmaniasis susceptibility in a canine cohort

BackgroundReports have shown correlations between the immune response to vector saliva and Leishmaniasis outcome. We followed dogs in an endemic area for two years characterizing resistance or susceptibility to canine visceral leishmaniasis (CVL) according to Leishmania infantum diagnosis and clinical development criteria. Then, we aimed to identify a biosignature based on parasite load, serum biological mediators’ interactions, and vector exposure intensity associated with CVL resistance and susceptibility.Methodology/Principal findingsA prospective two-year study was conducted in an area endemic for CVL. Dogs were evaluated at 6-month intervals to determine infection, clinical manifestations, immune profile, and sandfly exposure. CVL resistance or susceptibility was determined upon the conclusion of the study. After two years, 78% of the dogs were infected with L. infantum (53% susceptible and 47% resistant to CVL). Susceptible dogs presented higher splenic parasite load as well as persistence of the parasite during the follow-up, compared to resistant ones. Susceptible dogs also displayed a higher number of correlations among the investigated biological mediators, before and after infection diagnosis. At baseline, anti-saliva antibodies, indicative of exposure to the vector, were detected in 62% of the dogs, reaching 100% in one year. Higher sandfly exposure increased the risk of susceptibility to CVL by 1.6 times (CI: 1.11–2.41). We identified a discriminatory biosignature between the resistant and susceptible dogs assessing splenic parasite load, interaction of biological mediators, PGE₂ serum levels and intensity of exposure to sandfly. All these parameters were elevated in susceptible dogs compared to resistant animals.Conclusions/SignificanceThe biosignature identified in our study reinforces the idea that CVL is a complex multifactorial disease that is affected by a set of factors which are correlated and, for a better understanding of CVL, should not be evaluated in an isolated way.     

Enhanced attraction of sand fly vectors of Leishmania infantum to dogs infected with zoonotic visceral leishmaniasis

BackgroundThe sand fly Phlebotomus perniciosus is the main vector of Leishmania infantum, etiological agent of zoonotic visceral leishmaniasis in the Western Mediterranean basin. Dogs are the main reservoir host of this disease. The main objective of this study was to determine, under both laboratory and field conditions, if dogs infected with L. infantum, were more attractive to female P. perniciosus than uninfected dogs.Methodology/Principal findingsWe carried out a series of host choice experiments and found that infected dogs were significantly more attractive to P. perniciosus than uninfected dogs in the laboratory as well as in the field. Significantly more P. perniciosus fed on infected dogs than on uninfected dogs. However, the fecundity of P. perniciosus fed on infected dogs was adversely impacted compared to uninfected dogs by lowering the number of laid eggs. Phlebotomus perfiliewi, the second most abundant sand fly species in the field site and a competent vector of L. infantum had similar trends of attractivity as P. perniciosus toward infected dogs under field conditions.ConclusionsThe results strongly suggest that L. infantum causes physiological changes in the reservoir host which lead to the host becoming more attractive to both male and female P. perniciosus. These changes are likely to improve the chance of successful transmission because of increased contact with infected hosts and therefore, infected dogs should be particularly targeted in the control of zoonotic visceral leishmaniasis in North Africa.     

Toll‐deficient Drosophila is susceptible to Pythium insidiosum infection

There is a paucity of animal models of pythiosis, a life‐threatening disease of humans and animals, the immunopathogenesis of which is poorly understood. A pythiosis model was developed by injecting Toll (Tl)‐deficient Drosophila melanogaster flies with Pythium insidiosum zoospores. The infected Tl mutant flies had significantly lower survival rates (73.7%) than did control flies. This study reveals the important role of Tl pathway activation in fly immune response to pythiosis.     

Glycomic analysis of gastric carcinoma cells discloses glycans as modulators of RON receptor tyrosine kinase activation in cancer

BackgroundTerminal α2-3 and α2-6 sialylation of glycans precludes further chain elongation, leading to the biosynthesis of cancer relevant epitopes such as sialyl-Lewis X (SLe^X). SLe^X overexpression is associated with tumor aggressive phenotype and patients' poor prognosis.MethodsMKN45 gastric carcinoma cells transfected with the sialyltransferase ST3GAL4 were established as a model overexpressing sialylated terminal glycans. We have evaluated at the structural level the glycome and the sialoproteome of this gastric cancer cell line applying liquid chromatography and mass spectrometry. We further validated an identified target expression by proximity ligation assay in gastric tumors.ResultsOur results showed that ST3GAL4 overexpression leads to several glycosylation alterations, including reduced O-glycan extension and decreased bisected and increased branched N-glycans. A shift from α2-6 towards α2-3 linked sialylated N-glycans was also observed. Sialoproteomic analysis further identified 47 proteins with significantly increased sialylated N-glycans. These included integrins, insulin receptor, carcinoembryonic antigens and RON receptor tyrosine kinase, which are proteins known to be key players in malignancy. Further analysis of RON confirmed its modification with SLe^X and the concomitant activation. SLe^X and RON co-expression was validated in gastric tumors.ConclusionThe overexpression of ST3GAL4 interferes with the overall glycophenotype of cancer cells affecting a multitude of key proteins involved in malignancy. Aberrant glycosylation of the RON receptor was shown as an alternative mechanism of oncogenic activation.General significanceThis study provides novel targets and points to an integrative tumor glycomic/proteomic-profiling for gastric cancer patients' stratification. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.     

Canine leishmaniosis in Tunisia: Growing prevalence,larger zones of infection

BackgroundDiscovered by Nicolle and Comte in 1908 in Tunisia, Leishmania infantum is an intracellular protozoan responsible for zoonotic canine leishmaniosis (CanL) and zoonotic human visceral leishmaniasis (HVL). It is endemic in several regions of the world, including Tunisia, with dogs considered as the main domestic reservoir. The geographic expansion of canine leishmaniosis (CanL) has been linked to global environmental changes that have affected the density and the distribution of its sand fly vectors.Methodology/Principal findingsIn this study, a cross-sectional epidemiological survey on CanL was carried out in 8 localities in 8 bioclimatic areas of Tunisia. Blood samples were taken from 317 dogs after clinical examination. Collected sera were tested by indirect fluorescent antibody test (IFAT; 1:80) for the presence of anti-Leishmania infantum antibodies. The overall seroprevalence was 58.3% (185/317). Among positive dogs, only 16.7% showed clinical signs suggestive of leishmaniosis. Seroprevalence rates varied from 6.8% to 84.6% and from 28% to 66% by bioclimatic zone and age group, respectively. Serological positivity was not statistically associated with gender. The presence of Leishmania DNA in blood, using PCR, revealed 21.2% (64/302) prevalence in dogs, which varied by bioclimatic zone (7.3% to 31%) and age group (7% to 25%). The entomological survey carried out in the studied localities showed 16 species of the two genera (Phlebotomus and Sergentomyia). P. perniciosus, P. papatasi, and P. perfiliewi were the most dominant species with relative abundances of 34.7%, 25% and 20.4%, respectively.Conclusions/SignificanceThe present report suggests a significant increase of CanL in all bioclimatic areas in Tunisia and confirms the ongoing spread of the infection of dogs to the country’s arid zone. Such an expansion of infection in dog population could be attributed to ecological, agronomic, social and climatic factors that affect the presence and density of the phlebotomine vectors.     

Canine Gastrointestinal Pythiosis Treatment by Combined Antifungal and Immunotherapy and Review of Published Studies

Pythium insidiosum is an oomycete, a fungal like microorganism, which infects mammals, causing pythiosis in animals and humans, especially in tropical and subtropical regions around the world. The treatment for this infection is very difficult, and therapeutic options commonly comprise surgery, immunotherapy and antimicrobial drugs. The present report describes the clinical healing of a dog with gastrointestinal pythiosis by treatment with a combination of antifungals and immunotherapy, as well as reviews the cases reported in the literature that used some type of therapy for canine pythiosis. A 2.5-year-old male beagle initially showed sporadic vomiting episodes, and this symptom became more frequent 5 months after the onset of clinical signs. Celiotomy procedure found thickness of the stomach wall extending to the pylorus and duodenum. A biopsy was performed, and the diagnosis of pythiosis was made by mycological, histopathological analyses and molecular identification. Therapy was based on an association of terbinafine plus itraconazole during 12 months and immunotherapy for 2.5 months. The healing of the dog reported here allows us to propose the use of immunotherapy associated with antifungal therapy to treat canine gastrointestinal pythiosis. However, additional studies should be performed on a larger number of patients to establish a standard treatment protocol for canine pythiosis.     

High expression of heparanase-2 is an independent prognostic parameter for favorable survival in gastric cancer patients

Aim: Heparanase-2 expression has been suggested to up-regulate in several types of human cancers. However, the expression patterns of heparanase-2 in gastric cancer and its effect on prognosis of gastric cancer patients are unclear. Methods: In this study, the methods of tissue microarray, immunohistochemistry (IHC), and western blot were used to investigate heparanase-2 expression in gastric cancer and the adjacent non-cancerous tissues. Heparanase-2 expression was analyzed by immunohistochemistry in 95 clinicopathologically characterized gastric cancer cases. In addition Fisher's exact test, Kaplan–Meier plots and Cox proportional hazards regression model were used to analyze the results. Results: High expression of cytoplasmic heparanase-2 was observed in 70.5% (67/95) of gastric cancer, when compared with its normal counterpart. Overexpression of heparanase-2 was correlated with tumor size and differentiation (P < 0.05). Further analysis showed that a significant correlation between high expression of heparanase-2 and favorable prognosis (P < 0.05). In multivariate analysis, high expression of heparanase-2 was evaluated as an independent prognostic factor in gastric cancer (P < 0.05).ConclusionsOur data suggest for the first time that the high expression of heparanase-2 is associated significantly with tumor growth and differentiation. Importantly, heparanase-2 may be a potential molecular marker for predicting prognosis of gastric cancer.     

Isolation and Identification of Helicobacter spp. from Canine and Feline Gastric Mucosa

It is known that virtually all healthy adult dogs and cats harbor spiral helicobacters in their gastric mucosa. Three species, Helicobacter felis, Helicobacter bizzozeronii, and Helicobacter salomonis have been isolated in vitro from the gastric mucosa of these animals. The aims of this study were to evaluate the efficacy of an isolation method for canine and feline gastric helicobacters that has been developed at the University of Helsinki; to estimate the prevalence and distribution of these taxa in the samples examined; and to assess the efficacy and validity of an extensive set of standardized conventional phenotypic tests, whole-cell protein profiling, and ultrastructural analysis in identifying the different species isolated from canine and feline gastric mucosa. We cultured 95 and 22 gastric mucosal biopsies from dogs and cats, respectively. Twenty-one H. bizzozeronii strains, 8 H. felis strains, 8 H. salomonis strains, 3 mixed cultures, 2 “Flexispira rappini”-like organisms, and 3 as yet uncharacterized strains were isolated from the dogs, and 3 H. felis strains were isolated from the cats. The methods used here yielded Helicobacter isolation rates of 51% from dogs and 13.6% from cats, which exceed those reported previously. The main difficulties were primary isolation, mixed cultures, and identification to the species level. In the species identification, a detailed morphological examination was found to yield important phenotypic characteristics. A large panel of biochemical and tolerance tests did not clearly differentiate the closely related species H. bizzozeronii, H. felis, and H. salomonis. Highly standardized whole-cell protein profiling was shown to be an excellent method for species identification. Improvements in culture conditions for these bacteria are still needed, especially for cats. A genetic identification method not requiring culture is needed for future studies of these very fastidious helicobacters, as the clinical significance and ecology of these species within the gastric mucosa of the domestic carnivores remain largely unknown.     

β-Elemene inhibits the metastasis of multidrug-resistant gastric cancer cells through miR-1323/Cbl-b/EGFR pathway

Backgroundβ-Elemene is a natural agent extracted from the traditional Chinese herbal medicine Curcuma wenyujin that is a promising novel plant-derived drug with broad-spectrum anticancer activity. Our previous study identified an enhanced capacity for metastasis in multidrug resistant (MDR) gastric cancer and breast cancer cells. However, the anti-metastatic effects of β-Elemene on MDR cancer cells remain unknown.PurposeIn this study, we posit the hypothesis that β-elemene possesses antimetastatic effects on MDR cancer cells.MethodsCell viability assay was used to assess the resistance of SGC7901/ADR cells and the cytotoxic effects of β-Elemene. Wound healing, transwell assay and lung metastatic mice model were used to the anti-metastasis effects of β-Elemene. MicroRNA microarray analysis was used to explore potential regulated miRNAs. Luciferase reporter assay was used to identify the direct target. Human MMP antibody array, western blot, immunoprecipitation, qRT-PCR analyses and immunohistochemistry were conducted to investigate the underlying anti-metastasis mechanism of β-Elemene.ResultsIn this study, we found that β-Elemene significantly inhibited the metastatic capacity of MDR gastric cells in vivo and in vitro. Mechanistically, we found that β-Elemene regulated MMP-2/9 expression and reversed epithelial-mesenchymal transition. Further studies showed that β-Elemene upregulated Cbl-b expression, resulting in inhibition of the EGFR-ERK/AKT pathways, which regulate MMP-2/9. Additionally, we confirmed that β-Elemene upregulated Cbl-b by inhibiting miR-1323 expression. Finally, we found that numbers of metastatic tumor nodules were significantly decreased in the lungs of nude mice after β-Elemene treatment.ConclusionOur results suggested that β-Elemene inhibits the metastasis of MDR gastric cancer cells by modulating the miR-1323/Cbl-b/EGFR signaling axis.     

Auto-transplanted mesenchymal stromal cell fate in periodontal tissue of beagle dogs

Background aimsMesenchymal stromal cells (MSC) possess multilineage differentiation potential and characteristics of self-renewal. It has been reported that MSC can acquire characteristics of cells in the periodontal ligament (PDL) in vitro. Moreover, the transplantation of MSC has been shown to be a promising strategy for treating periodontal defects. However, little is known about the fate of MSC in periodontal tissue in vivo. The aim of this study was to trace the paths of MSC after transplantation into periodontal tissues in vivo.MethodsMSC labeled with bromodeoxyuridine (BrdU) were transplanted into periodontal defects of beagle dogs. Six weeks after surgery, the animals were killed and decalcified specimens were prepared. Migration and differentiation of MSC were detected by single/double immunohistochemistry and a combination of immunohistochemistry and in situ hybridization.ResultsBrdU-labeled MSC were observed distributing into periodontal tissue that included alveolar bone, PDL, cementum and blood vessels and expressing surface markers typical of osteoblasts and fibroblasts.ConclusionsCumulatively, our data suggest that MSC migrate throughout periodontal tissue and differentiate into osteoblasts and fibroblasts after transplantation into periodontal defects at 6 weeks in vivo, and have the potential to regenerate periodontal tissue.     

Factores asociados con la presencia de endoparásitos y ectoparásitos en perros domiciliados de la zona metropolitana de Toluca,México

Introduction:

Endoparasites and ectoparasites in dogs are of global distribution. The close relationship between dogs and man implies a risk for the transmission of zoonotic parasites. Therefore, it is necessary to determine the parasites hosted by dogs in specific areas and the factors associated with their presence.

Objectives:

To identify and to estimate the prevalence of endoparasites and ectoparasites in domiciled dogs in the Metropolitan area of Toluca, México, and the prevalence of D. caninum in fleas of the genus Ctenocephalides spp.

Materials and methods:

We collected samples from 402 domiciled dogs in four reference hospitals in the area in Toluca. We diagnosed endoparasites using direct smear, flotation, and sedimentation techniques and we performed the taxonomic identification of ectoparasites. Finally, the molecular diagnosis of D. caninum in fleas was made using the polymerase chain reaction technique (PCR).

Results:

A total of 37.2% of dogs were positive for endoparasites; the genera or species identified were Toxocara spp., Giardia spp., Ancylostoma spp., Cystoisospora spp., D. caninum, Taenia spp., and Trichuris vulpis; the prevalence of ectoparasites was 13.13%. We identified fleas of the species Ctenocephalides felis, Ctenocephalides canis; only one animal was parasitized with Rhipicephalus sanguineus and another one with Trichodectes canis; the prevalence of D. caninum in fleas was 9.5%.

Conclusion:

The prevalence of endoparasites was 37.2% while that of ectoparasites was 13.1%; this is the first analysis of endoparasites and ectoparasites conducted in the same population of dogs in México together with the molecular diagnosis of D. caninum in fleas.     

Identification of <Emphasis Type="Italic">Pythium insidiosum</Emphasis> by Nested PCR in Cutaneous Lesions of Brazilian Horses and Rabbits

Pythium insidiosum is a fungus-like organism present in subtropical and tropical areas, such as Brazil, known to infect humans and various animal species. P. insidiosum is the etiological agent of pythiosis, an emerging and granulomatous disease characterized mainly by cutaneous and subcutaneous lesions in horses, the principal species affected. Accurate diagnosis of pythiosis and identification of its causal agent by microbiological and serological tests can be often difficult and inconclusive principally for horses and humans. The aim of this study was to evaluate the application of the previously described P. insidiosum-specific nested polymerase chain reaction (PCR) assay to directly detect P. insidiosum DNA in clinical and experimental lesions. Universal fungal primers (ITS1 and ITS4) were used during the first-round of PCR to amplify ITS1, 5.8s, and ITS2. A second-round of PCR was conducted with P. insidiosum-specific primers (PI1 and PI2) to amplify a variable region within this ITS1. In this study, a total of 21 equine clinical samples (kunkers) and 28 specimens from experimentally infected rabbits were analyzed by nested PCR. The first-round of PCR generated 800-base pair products, and the second-round produced 105-base pair amplicons for each P. insidiosum-specific sample; no amplicons were generated in negative control samples. Our results suggest that nested PCR is an important and efficient tool for diagnosis of both endemic (horse samples) and experimental (rabbit samples) pythiosis.     

下丘脑室旁核orexin-A对大鼠摄食和胃动力影响及调控机制

目的:探讨下丘脑室旁核orexin-A对大鼠摄食和胃动力影响及调控机制。方法:采用免疫组化观察下丘脑室旁核(paraventricular nucleus,PVN)orexin受体表达情况;PVN注射orexin-A观察大鼠摄食、胃运动、胃酸分泌和胃排空的改变。结果:免疫组化实验显示大鼠PVN中存在orexin受体免疫阳性细胞。PVN注射orexin-A后,大鼠前三小时摄食增加,6 h和24 h摄食无显著改变。PVN微量注射orexin-A后,大鼠胃运动幅度和频率增加、胃排空增快并且胃酸分泌增多。[D-Lys-3]-GHRP-6可部分阻断orexin-A对摄食、胃运动、胃排空和胃酸分泌的促进作用,SB334867可完全阻断orexin-A对胃运动、胃排空和胃酸分泌的促进作用。结论:下丘脑室旁核orexin-A可能通过生长激素促泌素GHSR受体信号通路调控大鼠摄食及胃功能。