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Akira Ito

Publications and source records attributed to Akira Ito.

At least 37 records · Page 2Linked to original sources
PubMed2006

Assessment of real-time PCR for diagnosis of Mycoplasma pneumoniae pneumonia in pediatric patients.

We developed a real-time PCR to detect Mycoplasma pneumoniae with a primer set designed for the 16S rRNA gene. Clinical samples (n=937) were collected from children with community-acquired pneumonia between April 2002 and March 2004 at 12 Japanese medical institutions. Sensitivity of real-time PCR was calculated as 10 colony-forming units per reaction tube using a pMP01 plasmid carrying a 225-bp target DNA fragment of the 16S rRNA gene in M. pneumoniae M129, a standard strain. Results, obtained within 2 h, were compared with those of conventional culture and serologic methods. Of all cases tested, 151 (16.4%) and 129 (13.8%) were positive for M. pneumoniae by real-time PCR and by culture, respectively. Among the 151 cases, almost all of those tested serologically by passive agglutination showed a rise in M. pneumoniae antibody titre between acute and convalescent sera. We conclude that this real-time PCR can identify M. pneumoniae rapidly and fulfills the need for rapid identification, high sensitivity, and high specificity.

Adolescent↗
PubMed2006

Magnetic resonance imaging of alveolar echinococcosis experimentally induced in the rat lung.

Pulmonary alveolar echinococcosis (AE) caused by the metacestode of Echinococcus multilocularis is a lethal zoonosis and is a lesion secondarily induced by hematogenous dissemination from hepatic AE lesions. In the present study, a hematogenous pulmonary AE model was experimentally induced in rats by the injection of echinococcal larval tissue homogenate to the tail vein, and then the pathological and diagnostic aspects of pulmonary AE were examined by magnetic resonance imaging (MRI). Histological primary, mature and degenerated AE lesions were observed 5, 18 and 50 weeks after injection, respectively. These lesions were discriminated as signal-void, hypointense and hyperintense regions in T1-weighted MRI (T1WI), respectively. The change in signal intensity in T1WI might reflect the content of proteinaceous fluid as a result of AE cyst degeneration. Western blot analysis of sera with antibodies of two epitopes (Em18 and Em16) of E. multilocularis provided evidence for AE infection in the early stage. T1WI in combination with Western blot analysis could possibility become definitive and early signs of hematogenous pulmonary AE infection.

Animals↗
PubMed2006

Community surveys and risk factor analysis of human alveolar and cystic echinococcosis in Ningxia Hui Autonomous Region, China.

OBJECTIVE: To determine the true community prevalence of human cystic (CE) and alveolar (AE) echinococcosis (hydatid disease) in a highly endemic region in Ningxia Hui, China, by detecting asymptomatic cases. METHODS: Using hospital records and "AE-risk" landscape patterns we selected study communities predicted to be at risk of human echinococcosis in Guyuan, Longde and Xiji counties. We conducted community surveys of 4773 individuals from 26 villages in 2002 and 2003 using questionnaire analysis, ultrasound examination and serology. FINDINGS: Ultrasound and serology showed a range of prevalences for AE (0-8.1%; mean 2%) and CE (0-7.4%; mean 1.6%), with the highest prevalence in Xiji (2% for CE, 2.5% for AE). There were significant differences in the prevalence of CE, AE and total echinococcosis between the three counties and villages (with multiple degrees of freedom). While hospital records showed 96% of echinococcosis cases attributable to CE, our survey showed a higher prevalence of human AE (56%) compared to CE (44%). Questionnaire analysis revealed that key risk factors for infection were age and dog ownership for both CE and AE, and Hui ethnicity and being female for AE. Drinking well-water decreased the risk for both AE and CE. CONCLUSION: Echinococcosis continues to be a severe public health problem in this part of China because of unhygienic practices/habits and poor knowledge among the communities regarding this disease.

Adolescent↗
PubMed2006

Unique family clustering of human echinococcosis cases in a chinese community.

We have identified a significant focus and unusual clustering of human cases of cystic echinococcosis (CE) and alveolar echinococcosis (AE) in the village of Nanwan, Xiji County, Ningxia Hui Autonomous Region, in one of the most highly endemic areas for both diseases in China. The village, a Chinese Hui Islamic community, is composed of 167 members of four extended families. A total of 28 people died (12 of echinococcosis) since the village was first settled in the 1950s. Despite similar life patterns, the number of AE and CE cases occurring in each family was different. Overall, the prevalences of AE and CE were 9% (20 cases) and 5.9% (13 cases), with a combined prevalence of 14.9%. In contrast to CE, a comparison of the prevalence of AE indicated significant differences between the four family clusters. Although suggestive that host genotype might play a role in susceptibility to AE, this hypothesis requires further investigation.

Adolescent↗
PubMed2006

Dual infection of animal hosts with different Echinococcus species in the eastern Qinghai-Tibet plateau region of China.

The eastern Qinghai-Tibet plateau of China is a highly endemic region of echinococcosis where Echinococcus granulosus sensu stricto (sheep strain), Echinococcus multilocularis, and Echinococcus shiquicus are distributed sympatrically. We developed a polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method for the identification of the three species in this region. The PCR-RFLP showed the dual infection of animals with different Echinococcus spp. The first case was a domestic dog concurrently infected with adults of E. granulosus and E. multilocularis. The second case was a plateau pika (Ochotona curzoniae) harboring metacestodes of E. multilocularis and E. shiquicus in the liver. The high susceptibility of some mammalian hosts to the parasites and the high prevalence of the three co-endemic species probably increase the chance of mixed infections in the eastern Tibetan plateau.

Animals↗
PubMed2006

[A case of liver cysts with Em18-WB was useful for differential diagnosis].

A 72-year-old woman with multilocular liver cysts was admitted. This lesions seemed to be an alveolar hydatid disease. Two methods of Western blotting were used for serologic diagnosis. One method recognizes antigens of crude extracts of Echinococcus multilocularis (EM). The other method recognizes a purified antigen (Em18) of EM. Her serum only reacted with the former method and never reacted with Em18 antigen. Eighteen months after first admission, she had an operation. The resected specimen was diagnosed with simple cysts. Western blotting using Em18 antigen could greatly facilitate the differential diagnosis of simple liver cyst and alveolar hydatid disease.

Aged↗
PubMed2006

Short report: Evidence and potential for transmission of human and swine Taenia solium cysticercosis in the Piracuruca region, Piauí, Brazil.

The study conducted in the Cocal dos Alves municipality, located in the Piracuruca region of Piauí State, Brazil in November of 2003 was based on both a socio-behavioral survey and analysis of serum antibodies and parasitic materials. Pig raising is the main economic activity with 91.4% using extensive farming. On the studied population, 54.3% of people did not apply any sanitary measures to wastewater, 45.7% used septic tanks, and 69.1% consumed water without treatment. The data collected indicated the occurrence and active transmission of the taeniasis-cysticercosis complex in the region. One of seven voluntary persons was positive in antibody-ELISA tests using both native and recombinant antigens. Multiplex PCR and DNA sequencing of cyst samples obtained from a pig revealed the presence of the Afro-American genotype of Taenia solium. This study revealed the occurrence of human and porcine cysticercosis in the Piracuruca region of Piauí State, middle-north of Brazil.

Animals↗
PubMed2005

Challenges for control of taeniasis/cysticercosis in Indonesia.

Taeniasis/cysticercosis has been reported from several provinces of Indonesia: Papua (=former Irian Jaya), Bali, North Sumatra, East Nusa Tenggara, South East Sulawesi, Lampung, North Sulawesi, Jakarta, West Kalimantan, and East Java. The highest level of endemicity of taeniasis/cysticercosis has been found in Papua. Recent surveys in Jayawijaya District of Papua in 2000 and 2001 showed that 5 of 58 local people (8.6%) harbored the adult tapeworm, Taenia solium, whereas 44 of 96 people (45.8%), 50 of 71 pigs (70.4%), and 7 of 64 local dogs (10.9%) were seropositive for T. solium cysticercosis. Current surveys in Bali and Samosir District, North Sumatra during 2002-2005 revealed that Taenia saginata taeniasis has increased in incidence whereas T. solium cysticercosis is now rather rare compared to one-two decades ago in Bali. Taenia asiatica taeniasis is still common in Samosir District. Data from other provinces of Indonesia are very limited or unavailable. Control of these diseases is not a priority in the health or veterinary services, neither at central or local government levels. However, limited efforts toward control of the diseases have been implemented such as training of health personnel, community education on disease prevention, and provision of anthelminthics. A working group for control of the disease in Indonesia and an international collaboration have been established among Ministry of Health, Indonesia; University of Indonesia; and Asahikawa Medical College, Asahikawa, Japan since 1996. Future goals include implementation of active case finding (active surveillance) and treatment of tapeworm carriers, sustainable public health education, establishment of a system to check the quality of beef/pork and determine the distribution of infected animals and strengthening of laboratory capacity. Efforts to motivate provinces and districts should be implemented in developing the strategic plan to control of the disease. Given the considerable differences in cultures, religions, levels of education, socio-economic levels, daily habits and behaviour etc., control programmes must be adapted to the local situations.

Animals↗
PubMed2005

Taeniasis/cysticercosis in Papua (Irian Jaya), Indonesia.

Reports showed that an important parasitic zoonotic disease caused by Taenia solium, Taenia saginata and Taenia asiatica is found endemic in several areas of Indonesia including Papua, Bali and North Sumatra. At present it is known that the highest prevalence of taeniasis/cysticercosis in Indonesia, caused by T. solium is among the indigenous communities in Papua (formerly Irian Jaya). In the early 1970s, 8-9% of stool samples from the Enarotali hospital, Paniai District (Irian Jaya) were found positive with Taenia eggs. The samples were from members of the Ekari (Kapauku) ethnic group. Stool samples from the Moni ethnic group, living east of surrounding lakes, were egg negative. Cysticerci of T. solium were discovered in pigs. During the years 1973-1976 cases of burns increased and were ultimately found to be primarily associated with epileptic seizures induced by neurocysticercosis cases. Among 257 cases of burns, 88 cases (62.8%) were suffering from epileptic seizures before or during hospitalization. In the year 1981 T. solium seropositive persons were mostly (16%) found in the endemic Obano village. In 1997 the parasite was discovered in Jayawijaya District, which is located approximately 250 km east of Paniai District. During 1991-1995, a local health center in Assologaima, Jayawijaya District reported 1120 new cases with burns and a further 293 new cases of epileptic seizures among 15,939 inhabitants. The histopathologic appearance and mitochondrial DNA analysis found the cysts to be similar to those of T. solium from other regions of the world. Sensitive and specific serological diagnostic methods were used and improved. Cysticerci were detected in dogs, as well as in pigs. A coproantigen test for detection of adult tapeworms in patients was carried out. Medical treatment with praziquantel for taeniasis and albendazole for cysticercosis (with prednisone and sodium phenytoin treatment in cases with neurocysticercosis) was undertaken. Lifestyle, religion, and socioeconomic aspects are important issues in the perpetuation and enhancing the endemicity of T. solium taeniasis and cysticercosis in Papua, Indonesia.

Animals↗
PubMed2005

Taeniasis and cysticercosis in Bali and North Sumatra, Indonesia.

It has been reported that three human Taenia species are distributed in Indonesia: Taenia solium, Taenia asiatica and Taenia saginata. T. asiatica is well known in North Sumatra, especially on Samosir island in Lake Toba. T. solium and T. saginata are known from Bali. T. solium is most serious public health issue in Papua (former Irian Jaya). In this report, we briefly review the present situation of these three human Taenia species mainly in Bali and North Sumatra. For community based epidemiological survey, we have adopted and applied questionnaire, microscopic observation of eggs, coproantigen tests, coproDNA tests, mitochondrial DNA analysis and morphology for isolated specimens, serology for cysticercosis and taeniasis. For detection of taeniasis cases of both T. saginata and T. asiatica, questionnaire by expert doctors is perfect to detect worm carriers. Corpoantigen test developed for detection of taeniasis of T. solium is also highly reliable to detect taeniasis carriers in the community. Epidemiological data from these two islands 2002-2005 are reviewed with backgrounds of historical culture, religions and customs.

Animals↗
PubMed2005

Recent advances in characterization of Echinococcus antigen B.

Antigen B (AgB) in hydatid cyst fluid of Echinococcus granulosus is a polymeric lipoprotein of 160 kDa and a highly immunogenic major antigen in echinococcal infection. The antigen is comprised of a group of subunit monomers of approximately 8 kDa in molecular size. Recent studies have revealed that the E. granulosus AgB (EgAgB) shows a high degree of genetic variability and the genes encoding the EgAgB 8-kDa subunit monomers that have been identified to date could be grouped into four clades, corresponding to the genes EgAgB8/1, EgAgB8/2, EgAgB8/3 and EgAgB8/4. It has been suggested that the recombinant EgAgB8/2 (rEgAgB8/2) provides better performance in serodiagnosis of human cystic echinococcosis (CE) than does the recombinant EgAgB8/1 (rEgAgB8/1). The EgAgB has been identified as a protease inhibitor with an ability to inhibit recruitment of neutrophils and exploit activation of T helper cells by eliciting a non-protective Th2 cell response, predominantly in patients with progressive CE. Recently it has been revealed that AgB also exists in the cyst fluid of Echinococcus multilocularis. Five different cDNAs encoding the EgAgB homologues have been identified in vesicles, protoscoleces and/or immature adult worms of E. multilocularis and named as EmAgB8/1, EmAgB8/2, EmAgB8/3, EmAgB8/4 and EmAgB8/5. These genes appeared to be expressed in a developmentally regulated manner in the parasite life cycle. This review focuses on recent advances in molecular biological and immunological characterization of AgB from both of E. granulosus and E. multilocularis.

Animals↗
PubMed2005

Mitochondrial DNA diagnosis for taeniasis and cysticercosis.

Molecular diagnosis for taeniasis and cysticercosis in humans on the basis of mitochondrial DNA analysis was reviewed. Development and application of three different methods, including restriction fragment length polymorphism analysis, base excision sequence scanning thymine-base analysis and multiplex PCR, were described. Moreover, molecular diagnosis of cysticerci found in specimens submitted for histopathology and the molecular detection of taeniasis using copro-DNA were discussed.

Animals↗
PubMed2005

Recombinant antigens for serodiagnosis of cysticercosis and echinococcosis.

Diagnosis of cysticercosis/echinococcosis is primarily based on imaging techniques. These imaging techniques are sometimes limited by the small size of visualized lesions and atypical images, which are difficult to be distinguished from abscesses or neoplasms. Therefore, efforts have been directed toward identification and characterization of specific antigens of parasites for development of serodiagnostic method that can detect specific antibody. For cysticercosis, glycoproteins of 10-26 kDa in cyst fluid of Taenia solium have been widely accepted for serodiagnosis purpose. The glycoproteins consist of a very closely related family of 8-kDa proteins. We identified four genes (designated Ag1, Ag1V1, Ag2 and Ag2V1) encoding the 7- and 10-kDa polypeptides. Based on the antigenicities of these clones, Ag1V1 and Ag2 were chosen as ELISA antigens and the Ag1V1/Ag2 chimeric protein was expressed. The Ag1V1/Ag2 chimeric protein showed the similar sensitivity and specificity as the native glycoproteins. For alveolar echinococcosis, the 65-kDa protein of Echinococcus multilocularis protoscolices and Em18 has been considered as serodiagnostic antigens. The sensitivity and specificity of Em18 are very compatible to those of the recombinant 65-kDa protein. Recently, we demonstrated that Em18 was the proteolytic product of the 65-kDa protein following the action by cysteine proteinases. From the information of N-terminal amino acid sequences, molecular size and isoelectric point of Em18, recombinant Em18 ((349)K to (508)K of the 65-kDa protein, RecEm18) was expressed and evaluated for serodiagnostic value. RecEm18 has the potential for use in the differential serodiagnosis of alveolar echinococcosis.

Animals↗
PubMed2005

Genetic variation in Taenia solium.

Neurocysticercosis is a major zoonotic larval cestode infection that has a worldwide distribution and is of significant public health importance. Knowledge of the genetic structure of Taenia solium can be applied to the epidemiology and transmission of this disease, since genetic variants may differ in infectivity and pathogenicity. Molecular epidemiological approaches can also enable detailed studies of transmission. On a global scale, mitochondrial markers have differentiated between T. solium isolates from Asia and isolates from Africa/Latin America. Intraspecific variation in T. solium has been detected to some extent, using RAPD markers to differentiate between T. solium populations from different regions within Mexico. Markers currently available for T. solium have not been used to analyse genetic variation at the community or local level. The development of highly polymorphic markers such as microsatellites in T. solium can provide the means to examine genetic heterogeneity of tapeworm infection at the household, community and regional level. Preliminary studies suggest it is possible to analyse population genetic variation in communities using a range of polymorphic markers.

Animals↗
PubMed2005

Usefulness of severe combined immunodeficiency (scid) and inbred mice for studies of cysticercosis and echinococcosis.

The topics in this review are the usefulness of immunodeficient and inbred mice for studies of developmental biology, drug efficacy and host specificity in cysticercosis and echinococcosis. In non-obese diabetic severe combined immunodeficiency (NOD/Shi-scid) mice of both sexes, in vitro hatched oncospheres of all three human taeniid species (Taenia solium, Taenia saginata and Taenia asiatica) developed into cysticerci comparable to or bigger than those developed in their known intermediate host animals, whereas only females were susceptible to these infections in other scid mice of BALB/c, C57BL or C.B-17 inbred strains. Detailed morphological observation from post-oncospheral to cysticercus developmental stages is expected to be easy when we use NOD/Shi-scid mice experimentally inoculated with in vitro hatched oncospheres. Metacestocidal effect of oxfendazole was evaluated in NOD/Shi-scid mice experimentally inoculated with oncospheres of T. solium. In Echinococcus multilocularis infection, larval tissue proliferated without induction of inflammatory host responses in scid mice, thus facilitating isolation of the larval vesicles and protoscoleces for biochemical and molecular biological studies. Trans portal inoculation of metacestode tissues resulted in proliferation of secondary echinococcal foci localized exclusively in the liver without metastasis to other tissues or organs. The advantages of a mouse model for Echinococcus granulosus are also described.

Animals↗
PubMed2005

Echinococcus shiquicus, a new species from the Qinghai-Tibet plateau region of China: discovery and epidemiological implications.

In Shiqu County of the Qinghai-Tibet plateau, many wild and domestic mammals are involved in the transmission cycles of Echinococcus spp. Echinococcus multilocularis and Echinococcus granulosus genotype G1 (sheep strain) are sympatrically distributed in the plateau. In 1995, we identified a unique strobilate stage of Echinococcus from the Tibetan fox, Vulpes ferrilata, but considered it to be a variant of E. multilocularis. Subsequent molecular genetic studies revealed that a hydatid cyst from the plateau pika, Ochotona curzoniae, had unique mitochondrial DNA sequences which are dissimilar to any published sequences of Echinococcus. The same sequences were subsequently found in adult worms from Tibetan foxes. Morphological, genetic and ecological features of the cestode led us to designate a new species Echinococcus shiquicus. E. shiquicus has been found at other areas surveyed on the plateau; however, no infections in humans caused by E. shiquicus have been yet identified.

Animals↗
PubMed2005

Simultaneous alveolar and cystic echinococcosis of the liver.

Alveolar echinococcosis (AE) and cystic echinococcosis (CE), caused by infection with the larval stages of Echinococcus multilocularis and E. granulosus, respectively, are of major clinical importance. Reports of infection with AE or CE are very common, but instances of simultaneous or dual infection are rare. We report on four cases with mixed AE/CE infections in the liver, diagnosed using retrospective surgical records and active community surveys in southern Ningxia Hui Autonomous Region (NHAR), PR China, a recognized hyperendemic area for echinococcosis.

Adolescent↗