Both hypo- and hyperglycaemia are associated with increased fracture risk in Japanese people with type 2 diabetes: the Fukuoka Diabetes Registry

AIM

The impact of glycaemic control on fracture risk is controversial, which may be due to the possible presence of hypoglycaemia. The aim of this study was to separately investigate the impacts of severe hypoglycaemia and poor glycaemic control on fracture risk in people with type 2 diabetes.

METHODS

Overall, 4706 Japanese participants (2755 men and 1951 postmenopausal women) with type 2 diabetes (mean age 66 years) were followed prospectively (a median of 5.3 years; follow-up rate, 97.6%), and were stratified by severe hypoglycaemia status and glycaemic control. The primary outcome was fractures at any anatomic site.

RESULTS

Fractures occurred in 662 participants (249 men and 413 women). The age- and sex-adjusted incidence rates (expressed per 1000 person-years) were: 71.2 (multiple episodes of severe hypoglycaemia), 43.1 (one episode), 25.2 [HbA_1c < 53 mmol/mol (< 7%) without severe hypoglycaemia], 28.7 [HbA_1c 53 to < 64 mmol/mol (7% to < 8%) without severe hypoglycaemia], 27.7 [HbA_1c 64 to < 75 mmol/mol (8% to < 9%) without severe hypoglycaemia] and 40.5 [HbA_1c ≥ 75 mmol/mol (≥ 9%) without severe hypoglycaemia]. Multivariate-adjusted hazard ratios (95% confidence intervals) for fractures were 2.24 (1.56, 3.21) in those with multiple episodes of severe hypoglycaemia, and 1.42 (1.04, 1.95) in those with HbA_1c ≥ 75 mmol/mol (≥ 9%) without severe hypoglycaemia, compared with those with HbA_1c < 53 mmol/mol (< 7%) without severe hypoglycaemia.

CONCLUSIONS

Both severe hypoglycaemia and poor glycaemic control were significantly related to an increased risk of fracture in people with type 2 diabetes, although severe hypoglycaemia conferred a stronger risk.

Effects of pharmacological lesion of the nucleus retroambiguus region on the pharyngeal phase of swallowing

Pharyngeal swallowing is controlled by synaptic interactions within a swallowing central pattern generator (sw-CPG) that is composed of a dorsal and a ventral swallowing group (VSG). Here, we used electrical stimulation (10 s) of the superior laryngeal nerve (SLN; 20 Hz; pulse width: 100 μs) to explore the role of the VSG in an arterially-perfused brainstem preparation of rats. To investigate the effects of pharmacological lesion (local microinjection of an GABA(A)-R agonist) of the nucleus retroambiguus (NRA), a designated component of the VSG, we recorded phrenic (PNA) and vagal nerve (VNA) activities. Control SLN stimulation with stepwise increasing stimulus intensities (from 20 μA to 160 μA) elicited robust suppression of PNA and evoked sequential swallowing activity in the VNA. Lesioning of the NRA had no effect on the pattern of pharyngeal swallowing, but significantly increased the sensory gating of SLN inputs. We conclude that the NRA is not part of the VSG, but appears to have important roles for the central gating of swallowing.

An epidemiological survey of echinococcosis in intermediate and definitive hosts in Qinghai Province, China

In order to understand the epidemiological status of alveolar and cystic echinococcosis in intermediate and definitive hosts in Qinghai Province, China, during the period 2007-2011, we investigated the infection in humans and animals, including yaks, Tibetan sheep, Tibetan dogs, and wild foxes distributed in different counties around the province. Sera from local residents were examined using a rapid serodiagnostic kit to detect specific antibodies against Echinococcus. Seropositive samples were confirmed with B-scan ultrasonography and X-ray examinations. Yaks and Tibetan sheep were checked at slaughterhouses, and cysts and suspicious lesions were collected for analysis. A rapid diagnostic strip was used to detect Echinococcus adults in Tibetan dogs. Positive dogs were dewormed and the parasites collected. Wild foxes were trapped and necropsies performed with particular attention to the intestine. Forty-eight of 735 (6.4%) humans tested were positive and 475 of 854 (55.6%) Tibetan sheep and 85 of 352 (24.15%) yaks were infected with Echinococcus. Across different counties, 214 of 948 (22.57%) Tibetan dogs were positive, and five of 36 (13.9%) wild foxes were infected with Echinococcus. Molecular studies showed that all the infections detected in humans, domestic yaks, and Tibetan sheep were the G1 genotype (E. granulosus), whereas the parasites from Tibetan foxes and Tibetan dogs were E. shiquicus and E. multilocularis, respectively. In conclusion, Echinococcosis is hyperendemic in Qinghai Province in both its intermediate and definitive hosts and the G1 genotype of cystic Echinococcus is the dominant strain.

Analysis on Gene Expression Profile in Oncospheres and Early Stage Metacestodes from Echinococcus multilocularis

Alveolar echinococcosis is a worldwide zoonosis of great public health concern. Analysis of genome data for Echinococcus multilocularis has identified antigen families that can be used in diagnostic assays and vaccine development. However, little gene expression data is available for antigens of the egg and early larval stages. To address this information gap, we used a Next-Generation Sequencing approach to investigate three different stages (non-activated and activated oncospheres, and early stage metacestodes) of E. multilocularis (Nemuro strain). Transcriptome data analysis revealed that some diagnostic antigen gp50 isoforms and the antigen Eg95 family dominated in activated oncospheres, and the antigen B family dominated in early stage metacestodes. Furthermore, heat shock proteins and antigen II/3 are constantly expressed in the three stages. The expression pattern of various known antigens in E. multilocularis may give fundamental information for choosing candidate genes used in diagnosis and vaccine development.

Randomized clinical trial of defaecatory function after anterior resection for rectal cancer with high versus low ligation of the inferior mesenteric artery

Background

Defaecatory function is often poor after anterior resection. Denervation of the neorectum following high ligation of the inferior mesenteric artery (IMA) is a possible cause of impaired defaecatory function. The purpose of this randomized clinical trial was to clarify whether the level of ligation of the IMA in patients with rectal cancer affects defaecatory function.

Methods

Between 2008 and 2011, patients who underwent anterior resection for rectal cancer were randomized to receive either high or low ligation of the IMA. The primary endpoint was to demonstrate the superiority of low ligation in terms of defaecatory function.

Results

One hundred patients were enrolled in the study; 51 were randomized to high ligation of the IMA and 49 to low ligation. There were no differences between the groups in terms of clinical data, except tumour stage, which was more advanced in the high-ligation group (P = 0·046). Nor were there any differences in defaecatory function, self-assessment of defaecation, Faecal Incontinence Quality of Life scale or continence score between groups at 3 months and 1 year. The number of harvested lymph nodes was similar. The rate of symptomatic anastomotic leakage was 16 per cent in the high-ligation group and 10 per cent in the low-ligation group (P = 0·415).

Conclusion

The level of ligation of the IMA in patients with rectal cancer did not affect defaecatory function or the incidence of postoperative complications. Registration number: NCT00701012 (http://www.clinicaltrials.gov).

Where to deliver baits for deworming urban red foxes for Echinococcus multilocularis control: new protocol for micro-habitat modeling of fox denning requirements

BACKGROUND

Deworming wild foxes by baiting with the anthelmintic praziquantel is being established as a preventive technique against environmental contamination with Echinococcus multilocularis eggs. Improvement of the cost-benefit performance of baiting treatment is required urgently to raise and maintain the efficacy of deworming. We established a spatial model of den site selection by urban red foxes, the definitive host, to specify the optimal micro-habitats for delivering baits in a new modeling approach modified for urban fox populations.

METHODS

The model was established for two cities (Obihiro and Sapporo) in Hokkaido, Japan, in which a sylvatic cycle of E. multilocularis is maintained. The two cities have different degrees of urbanization. The modeling process was designed to detect the best combination of key environmental factors and spatial scale that foxes pay attention to most (here named 'heeding range') when they select den sites. All possible models were generated using logistic regression analysis, with "presence" or "absence" of fox den as the objective variable, and nine landscape categories customized for urban environments as predictor variables to detect the best subset of predictors. This procedure was conducted for each of ten sizes of concentric circles from dens and control points to detect the best circle size. Out of all models generated, the most parsimonious model was selected using Akaike's Information Criterion (AIC) inspection.

RESULTS

Our models suggest that fox dens in Obihiro are located at the center of a circle with 500 m radius including low percentages of wide roads, narrow roads, and occupied buildings, but high percentages of green covered areas; the dens in Sapporo within 300 m radius with low percentages of wide roads, occupied buildings, but high percentages of riverbeds and green covered areas. The variation of the models suggests the necessity of accumulating models for various types of cities in order to reveal the patterns of the model.

CONCLUSIONS

Our denning models indicating suitable sites for delivering baits will improve the cost-benefit performance of the campaign. Our modeling protocol is suitable for the urban landscapes, and for extracting the heeding range when they select the den sites.

Characterization of a surface glycoprotein from Echinococcus multilocularis and its mucosal vaccine potential in dogs

Alveolar echinococcosis is a refractory disease caused by the metacestode stage of Echinococcus multilocularis. The life cycle of this parasite is maintained primarily between foxes and many species of rodents; thus, dogs are thought to be a minor definitive host except in some endemic areas. However, dogs are highly susceptible to E. multilocularis infection. Because of the close contact between dogs and humans, infection of dogs with this parasite can be an important risk to human health. Therefore, new measures and tools to control and prevent parasite transmission required. Using 2-dimensional electrophoresis followed by western blot (2D-WB) analysis, a large glycoprotein component of protoscoleces was identified based on reactivity to intestinal IgA in dogs experimentally infected with E. multilocularis. This component, designated SRf1, was purified by gel filtration using a Superose 6 column. Glycosylation analysis and immunostaining revealed that SRf1 could be distinguished from Em2, a major mucin-type antigen of E. multilocularis. Dogs (n = 6) were immunized intranasally with 500 µg of SRf1 with cholera toxin subunit B by using a spray syringe, and a booster was given orally using an enteric capsule containing 15 mg of the same antigen. As a result, dogs immunized with this antigen showed an 87.6% reduction in worm numbers compared to control dogs (n = 5) who received only PBS administration. A weak serum antibody response was observed in SRf1-immunized dogs, but there was no correlation between antibody response and worm number. We demonstrated for the first time that mucosal immunization using SRf1, a glycoprotein component newly isolated from E. multilocularis protoscoleces, induced a protection response to E. multilocularis infection in dogs. Thus, our data indicated that mucosal immunization using surface antigens will be an important tool to facilitate the development of practical vaccines for definitive hosts.

Molecular survey of Tritrichomonas suis (=T. foetus) 'cat' and 'cattle' genotypes in pigs in Japan

Tritrichomonas suis (=T. foetus) is a protozoan parasite of pigs, cattle and cats. Based on host range and genetic differences, T. suis has been divided into a 'cat genotype' and a 'cattle genotype', with the latter genotype capable of infecting both cattle and pigs. Since no information is currently available on the genetic characteristics of T. suis from pigs in Japan, we conducted a molecular survey of T. suis using fecal DNA from pigs in Japan. Of the 64 pigs examined, nested PCR revealed that 36 (56.3%) were positive for T. suis. Sequence analysis of 8 positive samples showed that 7 of the pig isolates belonged to the 'cattle genotype' and the remaining isolate belonged to the 'cat genotype'. The findings revealed that T. suis infection is common in pigs in Japan and that pigs can be infected by both genotypes.

Mucosal adjuvanticity of fibronectin-binding peptide (FBP) fused with Echinococcus multilocularis tetraspanin 3: systemic and local antibody responses

Background

Studies have shown that a bacterial fibronectin attachment protein (FAP) is able to stimulate strong systemic and mucosal antibody responses when it is used alone or co-administrated with other antigens (Ags). Thus, it has been suggested to be a promising adjuvant candidate for the development of efficient vaccines. However, the co-administered Ags and FAP were cloned, expressed and purified individually to date. In a recent study, we first evaluated the adjuvanticity of a fibronectin-binding peptide (FBP, 24 amino acids) of Mycobacterium avium FAP fused with Echinococcus multilocularis tetraspanin 3 (Em-TSP3) by detecting systemic and local antibody responses in intranasally (i.n.) immunized BALB/c mice.

Methodology/Principal Findings

Em-TSP3 and FBP fragments were linked with a GSGGSG linker and expressed as a single fusion protein (Em-TSP3-FBP) using the pBAD/Thio-TOPO expression vector. BALB/c mice were immunized i.n. with recombinant Em-TSP3-FBP (rEm-TSP3-FBP) and rEm-TSP3+CpG and the systemic and local antibody responses were detected by ELISA. The results showed that both rEm-TSP3-FBP and rEm-TSP3+CpG evoked strong serum IgG (p<0.001) and IgG1 responses (p<0.001), whereas only the latter induced a high level IgG2α production (p<0.001), compared to that of rEm-TSP3 alone without any adjuvant. There were no significant differences in IgG and IgG1 production between the groups. Low level of serum IgA and IgM were detected in both groups. The tendency of Th1 and Th2 cell immune responses were assessed via detecting the IgG1/IgG2α ratio after the second and third immunizations. The results indicated that i.n. immunization with rEm-TSP3-FBP resulted in an increased IgG1/IgG2α ratio (a Th2 tendency), while rEm-TSP3+CpG caused a rapid Th1 response that later shifted to a Th2 response. Immunization with rEm-TSP3-FBP provoked significantly stronger IgA antibody responses in intestine (p<0.05), lung (p<0.001) and spleen (p<0.001) compared to those by rEm-TSP3+CpG. Significantly high level IgA antibodies were detected in nasal cavity (p<0.05) and liver (p<0.05) samples from both groups when compared to rEm-TSP3 alone without any adjuvant, with no significant difference between them.

Conclusions

I.n. administration of rEm-TSP3-FBP can induce strong systemic and mucosal antibody responses in immunized BALB/c mice, suggesting that fusion of Em-TSP3 with FBP is a novel, prospective strategy for developing safe and efficient human mucosal vaccines against alveolar echinococcosis (AE).

Echinococcus metacestodes form a laminated layer and develop strategies to escape host immune responses once the infection established on the liver of intermediated host. One of the most important strategies is thought to be immunoregulation, where some molecules (e.g., antigen B) impair dendritic cell (DC) differentiation and polarize immature DC maturation towards a non-protective Th2 cell response. Therefore, it is more feasible to kill Echinococcus oncospheres in the early stage of infection in the intestine and blood. Systemic and local immune responses are believed to play a crucial role on oncosphere exclusion. Among antigen delivery systems, i.n. administration is the most efficient one, inducing both systemic and a full-range of mucosal immune responses. FAP is necessary to M. avium and S. pyogenes to efficiently attach and invade epithelial cells, and has been suggested as a potent vaccine adjuvant. Mucosal immune responses are induced after FAP binds to the fibronectin protein of host microfold (M) cells and DCs are activated. We developed a one-step delivery system where FAP and other Ags can be expressed, purified and immunized as one protein. The systemic and, in particular, the mucosal antibody responses induced by the fusion protein were detected to evaluate the adjuvanticity of FBP.

A pilot study on developing mucosal vaccine against alveolar echinococcosis (AE) using recombinant tetraspanin 3: Vaccine efficacy and immunology

Background

We have previously evaluated the vaccine efficacies of seven tetraspanins of Echinococcus multilocularis (Em-TSP1–7) against alveolar echinococcosis (AE) by subcutaneous (s.c.) administration with Freund's adjuvant. Over 85% of liver cyst lesion number reductions (CLNR) were achieved by recombinant Em-TSP1 (rEm-TSP1) and -TSP3 (rEm-TSP3). However, to develop an efficient and safe human vaccine, the efficacy of TSP mucosal vaccines must be thoroughly evaluated.

Methodology/Principal Findings

rEm-TSP1 and -TSP3 along with nontoxic CpG ODN (CpG oligodeoxynucleotides) adjuvant were intranasally (i.n.) immunized to BALB/c mice and their vaccine efficacies were evaluated by counting liver CLNR (experiment I). 37.1% (p<0.05) and 62.1% (p<0.001) of CLNR were achieved by these two proteins, respectively. To study the protection-associated immune responses induced by rEm-TSP3 via different immunization routes (i.n. administration with CpG or s.c. immunization with Freund's adjuvant), the systemic and mucosal antibody responses were detected by ELISA (experiment II). S.c. and i.n. administration of rEm-TSP3 achieved 81.9% (p<0.001) and 62.8% (p<0.01) CLNR in the liver, respectively. Both the immunization routes evoked strong serum IgG, IgG1 and IgG2α responses; i.n. immunization induced significantly higher IgA responses in nasal cavity and intestine compared with s.c. immunization (p<0.001). Both immunization routes induced extremely strong liver IgA antibody responses (p<0.001). The Th1 and Th2 cell responses were assessed by examining the IgG1/IgG2α ratio at two and three weeks post-immunization. S.c. immunization resulted in a reduction in the IgG1/IgG2α ratio (Th1 tendency), whereas i.n. immunization caused a shift from Th1 to Th2. Moreover, immunohistochemistry showed that Em-TSP1 and -TSP3 were extensively located on the surface of E. multilocularis cysts, protoscoleces and adult worms with additional expression of Em-TSP3 in the inner part of protoscoleces and oncospheres.

Conclusions

Our study indicated that i.n. administration of rEm-TSP3 with CpG is able to induce both systemic and local immune responses and thus provides significant protection against AE.

Humans and rodents become infected with E. multilocularis by oral ingesting of the eggs, which then develop into cysts in the liver and progress an endless proliferation. Untreated AE has a fatality rate of >90% in humans. Tetraspanins have been identified in Schistosoma and showed potential as the prospective vaccine candidates. In our recent study, we first identified seven tetraspanins in E. multilocularis and evaluated their protective efficacies as vaccines against AE when subcutaneously administered to BALB/c mice. Mucosal immunization of protective proteins is able to induce strong local and systemic immune responses, which might play a crucial role in protecting humans against E. multilocularis infection via the intestine, blood and liver. We focused on Em-TSP3, which achieved significant vaccine efficacy via both s.c. and i.n. routes. The adjuvanticity of nontoxic CpG OND as i.n. vaccine adjuvant was evaluated. The widespread expression of Em-TSP3 in all the developmental stages of E. multilocularis, and the strong local and systemic immune responses evoked by i.n. administration of rEm-TSP3 with CpG OND adjuvant suggest that this study might open the way for developing efficient, nontoxic human mucosal vaccines against AE.

Coprological survey of alimentary tract parasites in dogs from Zambia and evaluation of a coproantigen assay for canine echinococcosis

Faecal samples were collected from the rectum of 540 domestic dogs from four districts (Lusaka, Katete, Petauke and Luangwa) in Zambia between 2005 and 2006 and prevalences of canine alimentary tract parasites were determined by coprological examination. Thirteen different ova and parasites including strongyle (43.3%), Spirocerca lupi (18.7%), taeniid (13.1%), Toxocara canis (7.6%), Sarcocystis sp.* (7.5%), Isospora sp.* (5.7%), Physaloptera sp.* (4.6%), Capillaria sp.* (2.8%), Dipylidium caninum (2.2%), Mesocestoides sp.* (2.0%), Ascaris sp.* (1.7%), Trichuris vulpis* (0.4%) and Schistosoma mansoni* (0.4%) were detected, Ascaris and Schistosoma probably originating from coprophagy. The species with asterisks and later-described Taenia multiceps are for the first time reported from dogs in Zambia. A coproantigen enzyme-linked immunosorbent assay (CoproAg-ELISA) developed for Echinococcus spp. revealed 43 positive dogs and 37 of these harboured taeniid eggs. From 63 of the 71 taeniid egg-positive samples, eggs and DNA thereof were isolated and subjected to a multiplex polymerase chain reaction for differentiating E. granulosus sensu lato, E. multilocularis and Taenia spp. Amplicons indicative for Taenia spp. were obtained from 60 samples. Sequencing of amplicons spanning part of the mitochondrial cytochrome c oxidase subunit 1 gene, which was possible with 38 samples, revealed 35 infections with T. hydatigena and 3 with T. multiceps. Therefore, the CoproAg-ELISA showed some positives, but concrete evidence for the existence of canine E. granulosus infection could not be established. Comparison of the results of the CoproAg-ELISA and Taenia species identification indicated that the CoproAg-ELISA cross-reacts with patent infections of T. hydatigena (57%) and T. multiceps (33%).

Comparison of clinical, tumour-related and dosimetric factors in grade 0-1, grade 2 and grade 3 radiation pneumonitis after stereotactic body radiotherapy for lung tumours

OBJECTIVE

The aim of this study was to investigate significant clinical, tumour-related and dosimetric factors among patients with grade 0-1, grade 2 and grade 3 radiation pneumonitis (RP) after stereotactic body radiotherapy (SBRT) for lung tumours.

METHODS

Patients (n=128) with a total of 133 lung tumours treated with SBRT of 50 Gy in 5 fractions were analysed. RP was graded according to the Common Terminology Criteria for Adverse Events v.3.0. Significant factors were identified by univariate and multivariate analyses. Threshold dose-volume histograms (DVHs) were constructed to identify the incidence of RP.

RESULTS

The median follow-up period was 12 months (range, 6-45 months). In univariate analyses, gender, operability, forced expiratory volume in 1 s (FEV1), internal target volume, lung volumes treated with doses >5-30 Gy (V5-30) and mean lung dose were significant factors differentiating between grade 0-1 and grade 2 RP, and V15-30 were significant factors differentiating between grade 2 and grade 3. However, no factors were significant between grade 0-1 and grade 3 RP. Multivariate analysis showed that female gender, high FEV1 and high V15 were significant factors differentiating between grade 0-1 and grade 2 RP. Threshold DVH curves were created based on ≤5% and ≤15% risk of grade 2 RP among patients with grade 0-2 RP.

CONCLUSIONS

Grade 0-2 RP was dose-volume dependent, and female gender and high FEV1 were significant predictive clinical factors for grade 2 RP among patients with grade 0-2 RP. However, incidences of V15-30 in grade 3 RP were significantly lower than those in grade 2 RP, and no significant clinical or tumour-related factors were found. Further studies are needed to identify the mechanism underlying the development of grade 3 RP after SBRT for lung tumours.

Zoophilic feeding behaviour of phlebotomine sand flies in the endemic areas of cutaneous leishmaniasis of Sindh Province, Pakistan

Leishmania (Leishmania) major has been identified as the major causative agent of cutaneous leishmaniasis in Sindh Province of southern Pakistan. To make a rational approach for understanding the pathogen transmission cycles, the sand fly species and their natural blood meals in the endemic areas were examined. Total DNA was individually extracted from sand flies collected in four villages in Sindh Province. PCR-RFLP (restriction fragment length polymorphism) and sequence analysis of the 18S ribosomal RNA gene revealed that female sand flies identified were Sergentomyia clydei/Sergentomyia ghesquierei/Sergentomyia magna (68.6%), Sergentomyia dubia (17.1%), Phlebotomus papatasi (7.4%), Phlebotomus alexandri-like sand flies (3.4%) and Sergentomyia dentata (3.4%). PCR amplification of leishmanial kinetoplast DNA did not result in positive signals, suggesting that all 175 tested female sand flies were not infected with leishmanial parasites or contained undetectable levels of leishmanial DNA. Amplification and sequencing of the vertebrate cytochrome b gene in 28 blood-fed sand flies revealed that P. papatasi fed on cattle and wild rat whereas P. alexandri-like specimens fed on human, cattle, goat and dog. Although Sergentomyia sand flies are generally known to feed on cold-blooded animals, S. clydei, S. dubia and S. ghesquierei preferred humans, cattle, goat, sheep, buffalo, dog, donkey, wild rat and Indian gerbil. The epidemiological significance of the zoophilic feeding on various host species by Phlebotomus and Sergentomyia sand flies in Pakistan is further required to study for better understanding the zoonotic transmission of sand-fly-borne pathogens and for appropriate management of the vectors.

Intestinal Tritrichomonas suis (=T. foetus) infection in Japanese cats

Tritrichomonas suis (=T. foetus) has recently been reported to be a causative agent of chronic large-bowel diarrhea in cats. While the disease was previously attributed to Pentatrichomonas hominis, the etiologic agent for feline trichomonal diarrhea was identified as T. suis. Although feline trichomonosis due to T. suis has been reported at prevalences ranging from 14 to 31% in Europe and the U.S., no reports of the pathogen have been published to date in Japan. In 2008, however, we encountered a case of feline trichomonosis at the Veterinary Teaching Hospital of Hokkaido University. The parasite was identified as T. suis by nested PCR amplification of partial internal transcribed spacer region 1 and 5.8S ribosomal RNA gene sequences with T. suis-specific primers and DNA sequencing of the amplified products. We then conducted surveys for feline trichomonosis in three different animal hospitals using either cultivation and/or PCR-based assays. The results revealed that 13 of 147 samples (8.8%) were positive for T. suis, and that 5 of the 13 infected cats, which ranged between 1 month and 7.5 years-old, showed chronic diarrhea. Seven of the infected cats were purebred and 6 were mixed breed. These findings suggested that feline trichomonosis is prevalent in Japan, and that T. suis may play a role as a causative agent of feline chronic diarrhea.

Echinococcus multilocularis: purification and characterization of glycoprotein antigens with serodiagnostic potential for canine infection

We show that a conventionally purified glycoprotein component of Echinococcus multilocularis protoscolex, designated as Emgp-89, may be useful as a serodiagnostic antigen for detecting E. multilocularis infection in dogs domesticated in endemic areas. Emgp-89 was obtained from the parasite material by a simple procedure using Con A-agarose and subsequent gel filtration chromatography. The purified fraction showed a molecular weight of >4000kDa upon gel filtration and reacted with a series of lectins that specifically bind to mannose, galactose, N-acetylglucosamine, and N-acetylgalactosamine. Subsequently, serodiagnostic performance of Emgp-89 was evaluated through enzyme-linked immunosorbent assays (ELISAs) by using sera from normal, domestic dogs and dogs infected with other helminths. Emgp-89 positively reacted with all 16 serum samples from E. multilocularis-infected dogs, thus showing that this antigen is highly sensitive. On the other hand, the specificity of Emgp-89-based ELISA, determined using 41 serum samples from dogs infected with other helminths, was relatively low (83%). As an attempt to improve the specificity of Emgp-89-based ELISA, we pretreated Emgp-89 with proteinase K or sodium periodate, expecting that these treatments would enable discrimination of true positives from false positives. The ELISA value increased after treatment with sodium periodate in most false-positive samples, whereas significant decreases were observed in sera from all dogs infected with E. multilocularis. Further evaluation of this antigen should be performed using sera from dogs infected with closely-related parasites, including taeniid cestodes, which are expected to prove that this serodiagnostic system is sufficiently specific for clinical and field applications.

Echinococcus multilocularis primary cells: improved isolation, small-scale cultivation and RNA interference

In this study we demonstrate RNA interference mediated knock-down of target gene expression in Echinococcus multilocularis primary cells on both the transcriptional and translational level. In addition, we report on an improved method for generating E. multilocularis primary cell mini-aggregates from in vitro cultivated metacestode vesicles, and on the cultivation of small numbers of small interfering RNA-transfected cells in vitro over an extended period of time. This allows assessments on the effects of RNA interference performed on Echinococcus primary cells with regard to growth, proliferation, differentiation of the parasite and the formation of novel metacestode vesicles in vitro.

Molecular phylogeny of the subfamily Gerbillinae (Muridae, Rodentia) with emphasis on species living in the Xinjiang-Uygur Autonomous Region of China and based on the mitochondrial cytochrome b and cytochrome c oxidase subunit II genes

Rodents belonging to the subfamily Gerbillinae and living in the Xinjiang-Uygur autonomous region of China were collected in field surveys between 2001 and 2003. We found four Meriones species, including M. chengi M. liycus, M. meridianus, and M. tamariscinus, as well as related species from different genera, Rhombomys opimus and Brachiones przewaliskii For phylogenetic analyses of these gerbilline species, DNA sequences of parts of the mitochondrial cytochrome b (Cytb) and cytochrome c oxidase subunit II (COII) genes were examined with the neighbor Joining, maximum parsimony, maximum likelihood, and Bayesian inference methods. Our phylogenetic analyses suggest that the genus Meriones is not monophyletic and place M. tamaricinus as the sister taxon to a clade comprising Brachiones, Psammomys, Rhombomys, and the other Meriones species. The remaining Meriones species separate into three lineages: M. meridianus (including M. chengi), Meriones unguiculatus, and a clade that includes multiple Meriones species originating from Asia, the Middle East, and Africa. The phylogenetic relationships among the genera Brachines, Meriones, Psammomys, and Rhombomys remain ambiguous, probably due to the saturation of mutations that occurs in fast-evolving mitochondrial DNA. In addition, intraspecific variation was observed for M. meridianus, and this mostly correlated with collection localities, i.e., the northern and southern parts of the Xinjiang region. This variation corresponded to interspecific levels of divergence among other lineages of Meriones. Interestingly, no differences were observed in either the Cytb or COII gene sequences isolated from M. chengi collected from the Turfan Basin in the north and those from M. meridianus in the south, suggesting that M. chengi may be a synonym of M. meridianus.

Echinococcus multilocularis: two-dimensional Western blotting method for the identification and expression analysis of immunogenic proteins in infected dogs

Domesticated dogs are an important potential source of Echinococcus multilocularis infection in humans; therefore, new molecular approaches for the prevention of the parasite infection in dogs need to be developed. Here, we identified and characterized an immunogenic protein of the parasite by using a proteome-based approach. The total protein extracted from protoscoleces was subjected to two-dimensional Western blotting with sera from dogs experimentally infected with E. multilocularis. Two protein spots showed major reactivity to the sera from infected dogs. The N-terminal amino acid sequences of these spots were identical to the deduced amino acid sequence of the product of the putative hsp20 gene. RT-PCR and Western blot analyses revealed that the putative hsp20 gene and its products were expressed in almost all stages of the parasite life cycle. Furthermore, recombinant hsp20 showed specific reactivity to the sera from infected dogs, suggesting that this molecule may facilitate the development of a practical vaccine.

Multiplex PCR system for identifying the carnivore origins of faeces for an epidemiological study on Echinococcus multilocularis in Hokkaido, Japan

A multiplex PCR system was developed to identify the carnivore origins of faeces collected in Hokkaido, Japan, for epidemiological studies on Echinococcus multilocularis. Primers were designed against the D-loop region of mitochondrial DNA. Two separate primer mixtures (mix 1, specific forward primers to fox, raccoon dog and dog, and a universal reverse primer [prH]; and mix 2, specific forward primers to cat, raccoon and weasels and prH) were used so that the PCR products (160 bp, fox and cat; 240 bp, raccoon dog and raccoon; and 330 bp, dog and weasel) were distinguished by size. The multiplex PCR exhibited no cross-reactivity between carnivore species and did not amplify DNA from rodent prey. When 270 field-collected faeces were examined, 250 showed single PCR products belonging to specific target sizes, suggesting successful carnivore identification for 92.6% of samples. Taeniid eggs were detected in 11.1% of samples and coproantigen in 30.4%; whereas the prevalences of taeniid eggs and coproantigen were 12.9% and 34.0% in fox faeces, and 0% and 26.3% in cat faeces, respectively. These results suggest that the prevalence in different target animals can be evaluated individually and precisely using multiplex PCR system.

Echinococcus multilocularis infection in pet dogs in Japan

A survey of Echinococcus multilocularis infections in pet dogs in Japan from 1997 to 2007 was conducted by testing for coproantigen reactivity, fecal taeniid eggs, and egg DNA. In Hokkaido, the only island where E. multilocularis is endemic in Japan, 18 of 4768 dogs (0.4%) excreted taeniid eggs that were positive for E. multilocularis DNA by polymerase chain reaction (PCR). Most of the dogs testing positive for egg DNA were kept free-range, but three dogs had been kept inside their owners' houses. In addition, 15 dogs were suspected to be infected based on the results of a coproantigen test. One dog, which was transported from Hokkaido to Honshu, the main island of Japan, was excreting taeniid eggs that were positive for E. multilocularis DNA by PCR. These results suggest the importance of proper pet management in disease prevention, even for dogs kept indoors, and they point out a possible means by which the parasite may be introduced into non-endemic areas through transport of infected dogs.

Molecular cloning and characterization of a T24-like protein in Echinococcus multilocularis

One tetraspanin, designated as E24, was cloned from a full-length enriched vector-capping cDNA library of Echinococcus multilocularis metacestode. The amino acid sequence and phylogenetic analysis suggested that E24 is a T24-like protein. The crucial, functional large extracellular loop (LEL) domain of E24 was expressed and characterized using a polyclonal antiserum by Western blot and immunohistochemistry. The results showed that anti-recombinant-E24 (anti-recE24) antibody can specifically recognize approximately 25 kDa recombinant protein and 25 kDa cyst-extracted antigen; the germinal layer of both the protoscolex-free and protoscolex-formed cysts were intensely labeled by immunofluorescent antibody. This study revealed that E24 is an antigenic, germinal layer-located protein of E. multilocularis metacestode, implying for its potential in diagnostic and vaccine development.

Monitoring of environmental contamination by Echinococcus multilocularis in an urban fringe forest park in Hokkaido, Japan

OBJECTIVES

The aim of this study was to determine the prevalence of Echinococcus multilocularis environmental contamination in an urban fringe-the Nopporo forest park of Sapporo city, Hokkaido, Japan. A secondary aim was to determine possible transmission risks areas by associating percentage occurrence of E. multilocularis-positive faeces with the different land-use classes.

METHODS

Wild fox faeces collected from the environment were examined by intravital methods, such as the taeniid egg sucrose floatation technique, E. multilocularis coproantigen enzyme-linked immunosorbent analysis and DNA test of taeniid eggs by PCR. Geospatial maps produced by the Global Positioning System and Landsat data were analysed using geographic information system software to determine the association between percentage occurrences of E. multilocularis-positive fox faeces and land-use classes.

RESULTS

Our findings showed high prevalence rates in both E. multilocularis egg and coproantigen-positive faeces (16 and 49%, respectively) in the investigated urban fringe forest park. Data revealed that percentage occurrence of E. multilocularis-positive fox faeces was associated with land-use classes, such as forest and open field (P < 0.05).

CONCLUSIONS

We conclude that Nopporo forest park in the urban fringe of Sapporo city, Hokkaido is a reservoir with a high prevalence of zoonotic infective agents for alveolar echinococcosis. Our findings suggest that interface habitats between forests or woodlands and open fields are indispensable for continued maintenance of the life-cycle of E. multilocularis and, as such, constitute high risk areas for echinococcosis transmission.

Evaluation of efficacy of bruceine A, a natural quassinoid compound extracted from a medicinal plant, Brucea javanica, for canine babesiosis

Bruceine A, a natural quassinoid compound extracted from the dried fruits of Brucea javanica (L.) Merr., was evaluated for its antibabesial activity in vitro and in vivo. Bruceine A inhibited the in vitro growth of Babesia gibsoni in canine erythrocytes at lower concentration compared with the standard antibabesial drug diminazene aceturate and killed the parasites within 24 hr at a concentration of 25 nM. Oral administration of bruceine A at a dosage of 6.4 mg/kg/day for 5 days resulted in no clinical findings in a dog with normal ranges of hematological and biochemical values in the blood. Three dogs were infected with B. gibsoni and two of them were treated with bruceine A at a dosage of 6.4 mg/kg/day for 6 days from day 5 post-infection. An untreated dog developed typical acute babesiosis symptoms including severe anemia, high fever, and complete loss of appetite and movement. However, the two bruceine A-treated dogs maintained their healthy conditions throughout the experimental period of 4 weeks although complete elimination of parasites from the peripheral blood was not achieved and decreases in the packed cell volume and the erythrocyte and platelet counts were observed. Since natural quassinoid compounds have been used as traditional medicines for the treatment of various ailments including cancer and malaria, the present results suggest that bruceine A or other related compounds are potential candidates for the treatment of canine babesiosis.

Abdominal cysticercosis in a cynomolgus monkey

Cysticercus tenuicollis, the larval form of Taenia hydatigena, was observed in a 5-year-old male cynomolgus monkey used in a toxicity study for a safety assessment of a pharmaceutical. The animal was born and raised in a primate colony in China. A pale yellow cyst filled with more than 100ml of pale yellow fluid was found in the abdominal cavity in the autopsy. The cyst was found attached to the greater omentum, and it was double layered. Histopathologically, the outer layer was a part of the greater omentum, and the inner layer was the bladder wall of a cysticercus with a well developed scolex. A partial sequence of mitochondrial NADH dehydrogenase subunit 1 showed a high homology to the same region of Taenia hydatigena (1.5-3.3%).

Taenia taeniaeformis: colonic hyperplasia in heavily infected rats

Only one study previously mentioned the involvement of colon during Taenia taeniaeformis larvae infection in rats with inconsistent occurrence of lesions. Present study aimed to determine the consistency of histopathologic changes in colonic epithelia, and the proliferation of mucosal cells through BrdU and PCNA immunohistochemistry. Results demonstrated that crypt hyperplasia of the colon was found in all infected rats, although variable in degree even in a single tissue section. Cystic cavities were frequently seen in severely hyperplastic mucosa. Proliferative zone lengths were significantly increased and PCNA positive cells were observed throughout the colonic crypt lengths at 9 but not at 6 weeks post infection. Cell proliferation involving the major types of cells in the epithelial colon was also increased in infected rats at 9 weeks post infection, with labeling indices significantly greater than the control rats throughout the BrdU time course labeling. Findings suggested that massive increases in epithelial cells and depth of colonic crypts were due to a remarkable increase in cell proliferation. The study concluded that enteropathy in the colon during T. taeniaeformis infection could be consistently observed in heavily infected rats.

Immunohistochemical characterization of cellular proliferation in small intestinal hyperplasia of rats with hepatic Strobilocercus fasciolaris infection

Rats infected with the larvae of Taenia taeniaeformis harbour the intermediate stage of the parasite Strobilocercus fasciolaris within the liver. Affected animals also develop gastric and intestinal hyperplasia. The pathogenesis of the gastric hyperplasia has been extensively investigated, but few studies have addressed the nature of the intestinal changes. This study characterizes the proliferation of small intestinal epithelial cells by immunohistochemical labelling for proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU) uptake. At 6 weeks post-infection (wpi) there was an increase in villous length but crypt depth was normal. At 9 wpi there was evidence of epithelial hyperplasia, increased villous length and crypt depth, and expansion of zones of epithelial proliferation. Immunohistochemical labelling indicated that an increase in the number of proliferating cells produced a greater number of progeny cells. Intestinal hyperplasia during experimental infection with T. taeniaeformis larvae is likely to be related to the associated gastropathy, although the mechanisms underlying both changes remain undefined.

The use of tetracycline in anthelmintic baits to assess baiting rate and drug efficacy against Echinococcus multilocularis in foxes

Anthelmintic (praziquantel) baiting of wild red foxes against Echinococcus multilocularis infection was studied in a highly epizootic suburban area of Otaru, Hokkaido (the northern island of Japan) during the summer and autumn in the years 1999-2004. Acceptance of baits containing the biomarker tetracycline (TC) was evaluated. The prevalence of E. multilocularis infection in foxes before baiting (1999-2000) was 58% (88/153), whereas in the fourth year of bait distribution year (2004), it decreased to 11% (5/45). Analysis of TC marking in the teeth of foxes showed that 39% (77/195) of those captured after baiting were estimated to have consumed baits in the year of capture. Importantly, more juvenile (56%, 49/87) than adult foxes (26%, 28/108) were marked, indicating efficient baiting of juveniles, which tended to have a higher worm burden of E. multilocularis. Of 77 marked foxes, E. multilocularis and Alaria alata (monitored as the second indicator species of deworming) were not detected in 70 (90%) and 76 (99%) foxes, respectively. The results suggest effective deworming by bait consumption. However, it was also demonstrated that 9% of the marked foxes were infected or re-infected after bait consumption, suggesting high infection pressure and the importance of frequent baiting.

The vaccination potential of EMY162 antigen against Echinococcus multilocularis infection

Alveolar echinococcosis is caused by infection with the larval stage of Echinococcus multilocularis. We recently identified a cDNA clone, designated as emy162, that encodes a putative secreted protein. EMY162 shares structural features with the EM95 antigen, which is a host-protective antigen. The amino acid sequence of EMY162 shows 31.4% identity to EM95 whereas these antigens are distinguishable with respect to their predicted secondary structure and antigenicity on Western blot analysis. RT-PCR analysis revealed that the gene expression of emy162 was significantly higher than that of em95 at each life-cycle stage. Recombinant EMY162 antigen induced a significant level of host-protection (74.3%) in experimental infection with E. multilocularis eggs in mice. Notably, recombinant EMY162 antigen showed significant reactivity to the sera from alveolar echinococcosis patients. These results may help in the development of a practical vaccine to reduce the level of alveolar echinococcosis in humans.

Research on targeting sources of alveolar echinococcosis in Japan

Echinococcus multilocularis is a fatal zoonotic parasite in the Northern Hemisphere. Recently, it has become endemic in many countries in Asia, especially in the northern island of Hokkaido in Japan. The increasing threat of public health due to alveolar echinococcosis has compelled researches for sensitive diagnosis and effective control. This paper reviews on the epidemiology, diagnosis and control of echinococcosis specifically in Japan. International collaborative responses by researchers and government initiatives such as mandatory reporting system for veterinarians who diagnose echinococcosis in dogs are presented. Successful control measures in Japan using anthelmintic fortified baits for foxes are described. Assessment of prevalence rates during control campaigns is analyzed favoring the use of intravital diagnosis rather than the traditional necropsy method from hunting or trapping activities of wild foxes. The novel concept of "endogenous development" by local resident volunteers towards sustainable control of echinococcosis is stressed.