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Biomedical subjects

H Itagaki

Publications and source records attributed to H Itagaki.

At least 37 records · Page 2Linked to original sources
PubMed1996

Ultrastructure of the cyst wall of Sarcocystis species with canine final host in Japan.

The ultrastructural characteristics of cyst wall are a useful clue to the identification of Sarcocystis species. Among the eight species examined, S. cruzi, S. sp. 1 from sheep and S. hircicanis had the thin cyst wall with long, tapered hair-like villar protrusions. The protrusions arose from the dome-like bulges of cyst wall and ran parallel to the surface. No clear ramification was observed in the tip of protrusion of these three species. S. tenella, S. capracanis, S. miescheriana, S. fayeri, and S. sp. 2 from Japanese deer had the thick cyst wall. The villar protrusions of the former three species were palisade-like in shape, but those of S. tenella and S. Capracanis were slightly thinner than those of S. miescheriana. The villar protrusions of S. fayeri and S. sp. 2 were finger-like, but those of the former species were shorter and thicker than those of the latter species. S. fayeri had many minute depressions on the surface of protrusion in a reticular pattern. Microtubules in the core of protrusion were seen in S. miescheriana, S. fayeri and S. sp. 2 but not in the other species. Microdepressions were observed on the surface of cyst wall among the protrusions in all the Sarcocystis species examined, but their function was not made clear.

Animals↗
PubMed1995

Functional mapping of the human somatosensory cortex with echo-planar MRI.

The somatotopical organization of the human somatosensory cortex was analyzed with echo-planar imaging at 1.5 Tesla, utilizing deoxyhemoglobin as an endogenous contrast medium. Scrubbing stimulation at a frequency of 3 Hz was applied to one of three cutaneous areas: toes, fingertips, and tongue tip. Parasagittal echo-planar slices were obtained every 2 s. We found focal bands of increased signal intensity (4% on average) during the stimulation, with a rise time of 2-6 s. These activated bands were located on the contralateral postcentral gyrus. The cortical responses from the three stimulation sites were anatomically distinct and organized medially-to-laterally in the order of toes, fingertips, and tongue tip.

Adult↗
PubMed1995

Hemoglobin denaturation caused by surfactants.

The properties of hemoglobin denaturation caused by two anionic surfactants (sodium dodecylsulfate and sodium lauroylmethyltaurate) were examined using spectrophotometry (multi-plate reader), circular dichroism (CD) and high-performance liquid chromatography (HPLC), and their denaturating action on hemoglobin and sorption to it were examined by various methods. Correlation and factorial analyses were applied to the experimental data and the following results were obtained: (1) High correlations were found among sorption, denaturation and alpha-helix content and the random structure of hemoglobin. (2) The alpha-helix of hemoglobin is randomized as the surfactants denature hemoglobin. (3) Factorial analysis indicates that there are two factors involved in hemoglobin denaturation, one related to the destruction of the alpha-helix and the other related to a change in the beta-structure. These two factors are related to change in the environment around the heme group. (4) Destruction of the alpha-helix seems to be one of the causes of the eye irritation produced by anionic surfactants.

Chromatography, High Pressure Liquid↗
PubMed1995

Toxicity and properties of the extract from Sarcocystis cruzi cysts.

The extract from Sarcocystis cruzi cysts in bovine muscle was subcutaneously injected to mice, guinea pigs, chickens, and rabbits to detect its toxicity. Only rabbits showed reactions after administration of the extract at a dose of 25 micrograms. The main clinical signs of the rabbits were depression, reduction in body temperature and intermittent diarrhea and the hematological findings observed were elevation in WBC, RBC, PCV, TP, BUN, AST, AUT and creatinine values and reduction in glucose, K+ and pH of blood. The extract, crude toxin, was a water soluble, acid-alkali stable and thermolabile protein and estimated to be a molecular mass of 15-16 kd.

Animals↗
PubMed1995

Analysis of Fasciola sp. antigen by enzyme-linked immunotransfer blot using sera from experimentally and naturally infected cattle.

Soluble polypeptides extracted from adult Fasciola sp. were analysed by SDS-PAGE, and their antigenicity was characterized by enzyme-linked immunotransfer blot (EITB) using sera from experimentally and naturally infected cattle. Polypeptides of adult Fasciola sp. with estimated molecular mass of 64-52 kDa, 38-28 kDa, 17 kDa, 15 kDa, 13 kDa and 12 kDa, were recognized by sera obtained in both early and late stages of infection. Furthermore, two polypeptides of more than 160 kDa were detected by sera only in the early stage of infection. The results of EITB using sera of dairy cows naturally infected with Fasciola sp. suggest that polypeptides of 64-52 kDa may be candidates as serodiagnostic antigen of bovine fascioliasis.

Animals↗
PubMed1994

Preparation and applicability of Sarcocystis cruzi antigens and their anti-S. cruzi rabbit sera for serodiagnosis of bovine sarcocystosis.

Sarcocystis cruzi antigens and their antisera were prepared for the seroimmunological diagnosis of bovine sarcocystosis. Fresh S. cruzi cysts directly removed from cardial muscle of slaughtered cattle were digested with trypsin to release bradyzoites. By twelve cycles of freezing at-22 degrees C and thawing at 37 degrees C, bradyzoites were let to leach out soluble material. The soluble antigens were inoculated four times to rabbits at a dose of 343 micrograms protein and anti-S. cruzi sera were prepared with blood of the rabbits. Gel immunodiffusion test showed no cross-reaction between the present antigens and any of anti-Toxoplasma gondii, -Hammondia hammondi and -Besnoitia wallacei rabbit sera. Avidin-biotin complex immunoperoxidase (ABC) technique with the present anti-S. curzi rabbit sera showed clear positive reaction against S. cruzi cysts in the muscular sections of infected cattle.

Animals↗
PubMed1994

Experimental infection of raccoon dogs with Sarcocystis cruzi and S. miescheriana.

Raccoon dogs were successfully infected with Sarcocystis cruzi and S. miescheriana by oral inoculation of infected cardiac muscle of cattle and pigs slaughtered in Saitama and Okinawa prefectures, respectively. Oocysts and sporocysts passed by raccoon dogs were similar in measurements and morphological features as reported of S. cruzi and S. miescheriana respectively. The prepatent and patent periods of both S. cruzi and S. miescheriana were 9 and 66-72 days respectively in raccoon dogs.

Animals↗
PubMed1994

Infectivity of three species of Fasciola to Wistar rats.

The infectivity of Fasciola spp. to Wistar rats was evaluated with the recovery rate and development of flukes. The recovery rate from the liver parenchyma and bile duct was 20.0-30.0% in F. hepatica, 36.6-47.5% in Japanese Fasciola sp. and 0-5.0% in F. gigantica. Mature flukes were first recovered at week 8 in F. hepatica and week 12 in Japanese Fasciola sp., however, F. gigantica did not mature in the rats examined until 12 weeks after infection. These results suggest that F. hepatica and Japanese Fasciola sp. are high in infectivity to Wistar rats, whereas F. gigantica is low.

Animals↗
PubMed1993

Chronic Sarcocystis infections in slaughtered cattle.

Parasitological, histopathological and immunohistochemical examinations were carried out on three slaughtered cattle with many nodules in all the striated muscles. At necropsy, many yellowish green rice-grain sized nodules including cheesy contents were observed in all the striated muscles. Histopathologically the nodules were granuloma principally consisting of eosinophiles. No Sarcocystis cysts nor bradyzoites were found in the nodules, but intact sarcocysts were found in the normal tissues surrounding the nodules. The central necrotic focus of nodules showed intense positive responses against anti-Sarcocystis cruzi rabbit serum by immunohistochemical examination. From the above findings the slaughtered cattle were diagnosed as chronic sarcocystiasis.

Animals↗
PubMed1992

Interneurons of the subesophageal ganglion of Sarcophaga bullata responding to gustatory and mechanosensory stimuli.

Intracellular recordings were made from interneurons in the subesophageal ganglion (SEG) of Sarcophaga bullata while stimulating the labellar lobes with solutions of sucrose, NaCl and with distilled water. Neurons that responded to sucrose did not respond to NaCl and vice versa, while sucrose-sensitive neurons often responded weakly to water. Several of the recorded neurons were filled with Lucifer Yellow, and their morphology was reconstructed. Most showed extensive arborizations within the SEG, suggesting that they were local interneurons involved in the early stages of gustatory processing. Some of the filled neurons had extensive projections to the brain, in addition to arborizations in the SEG. This is the first published record of gustatory interneurons in the higher flies.

Animals↗
PubMed1992

[Hemiplegic migraine complicated with coronary vasospasm].

There are many theories and hypotheses concerning with the pathogenesis of migraine. The clinical effectiveness of vasoactive drugs and many investigations on the cerebral blood flow in patients with migraine strongly support a vascular theory. In present paper we report a case of 26-year-old Japanese male, who suffered from hemiplegic migraine and coincidental coronary vasospasm, and discussed the pathogenesis of migraine. In October 1986, the patient developed the first attack of throbbing headache in the left temporal area with nausea and vomiting, following typical visual aura. One week later, he developed the second migrainous attack and then he felt his right extremities paralyzed and numb. Although the headache and weakness resolved within one hour, similar migrainous attack with transient hemiparesis repeated two or three times a month. Although the longest period required for resolving weakness was three days, the MRI, the CT and the electroencephalogram revealed no significant abnormality. In January 1987, during his stereotyped attack of hemiplegic migraine, he also developed oppressive feeling on his anterior chest and these symptoms resolved within fifteen minutes. Because the results of Holter electrocardiogram and ultrasound echocardiogram indicated angina pectoris, a coronary angiography was performed in February 1987. During the angiographical procedures, he began to complain of the oppressive feeling on his anterior chest, and the coronary angiography revealed the definite vasospasm in the anterior descending branch of the left coronary artery. Sublingual nitroglycerin administration resolved the vasospasm, but thereafter the patient developed his stereotyped hemiplegic migrainous attack.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Innervation and neural regulation of the sex pheromone gland in female Heliothis moths.

Female Heliothis moths normally produce their species-specific male attractant (sex pheromone blend) during scotophase, and this production is stimulated by pheromone biosynthesis activating neuropeptide (PBAN), presumably carried in the hemolymph. Several lines of evidence indicate that the central nervous system plays another critical role in this regulation. Pheromone biosynthesis was induced during photophase by electrical stimulation of the ventral nerve cord or the peripheral nerves projecting from the terminal abdominal ganglion to the pheromone gland in the tip of the abdomen. Electron microscopy further revealed that axonal branches innervate the gland tissue. Nerve branches associated with pheromone gland cells are enwrapped in glia and contain dense-core vesicles, suggesting that the innervation of the gland might be neurosecretory. Finally, the biogenic monoamine octopamine was nearly as effective as purified Heliothis zea PBAN in stimulating pheromone biosynthesis when injected into intact females during mid-photophase. Furthermore, both octopamine and PBAN stimulated significant increases in the pheromone content of the glands in isolated abdomens lacking a ventral nerve cord but only when abdomens were treated at the onset of scotophase. These data suggest that the regulation of sex pheromone production in Heliothis is more complex than previously thought. Activation of the gland appears to be governed by both neural and hormonal mechanisms, and these control mechanisms depend on photoperiodic cues.

Animals↗
PubMed1991

Evaluation of a new method for identification of Cryptococcus neoformans which uses serologic tests aided by selected biological tests.

A new method for identifying Cryptococcus neoformans isolates and their serotypes by the slide agglutination test using five kinds of factor sera, with the aid of nitrate reduction, phenol oxidase, and growth at 37 degrees C tests was evaluated by using 36 reference strains and 75 clinical isolates of C. neoformans. The results showed that the reference strains were identified exactly as they were labeled, and clinical isolates were identified as C. neoformans serotypes A, D, and AD. C. neoformans could be distinguished from other Cryptococcus species that cross-reacted with factor sera by their ability to grow at 37 degrees C. These results indicate that the slide agglutination test combined the use of factor sera for isolates which grow at 37 degrees C is a useful method for identification of C. neoformans and their serotypes and that the nitrate reduction test (negative in 100% of the isolates) and the phenol oxidase test (positive in approximately 95% of the isolates) can be used to confirm that the species is C. neoformans.

Agglutination Tests↗
PubMed1991

Anthelmintic efficacy of milbemycin D against Toxocara cati and Ancylostoma tubaeforme in domestic cats.

Anthelmintic efficacy of milbemycin D was evaluated against Toxocara cati and Ancylostoma tubaeforme in domestic cats. Twelve cats naturally infected with each nematode species were allocated among 2 groups of 6 animals each, and milbemycin D was orally administered to the 2 groups of cats in doses of 0.05 mg/kg and 0.1 mg/kg body weight, respectively. In all the cats infected with T. cati, fecal egg counts decreased followed by their disappearance from the feces and 2-35 worms were excreted into the feces after the medication in both doses of 0.05 mg/kg and 0.1 mg/kg. At postmortem of these medicated groups, no worms were detected from 4 cats of each group, but 1 and 2 immature worms were recovered from the other 2 cats respectively. In the cats infected with A. tubaeforme, fecal egg counts decreased followed by the disappearance from the feces and 2-62 worms were excreted into the feces in all the cats of the 2 groups, no nematodes remaining at postmortem. These results indicate that milbemycin D is fully effective against T. cati and A. tubaeforme in cats in a dose of 0.05-0.1 mg/kg.

Ancylostomiasis↗
PubMed1990

Olfactory interneurons in the brain of the larval sphinx moth Manduca sexta.

1. The physiology and morphology of olfactory interneurons in the brain of larval Manduca sexta were studied using intracellular recording and staining techniques. Antennal olfactory receptors were stimulated with volatile substances from plants and with pure odorants. Neurons responding to the stimuli were investigated further to reveal their response specificities, dose-response characteristics, and morphology. 2. We found no evidence of specific 'labeled-lines' among the odor-responsive interneurons, as none responded exclusively to one plant odor or pure odorant; most olfactory interneurons were broadly tuned in their response spectra. This finding is consistent with an 'across-fiber' pattern of odor coding. 3. Mechanosensory and olfactory information are integrated at early stages of central processing, appearing in the responses of some local interneurons restricted to the primary olfactory nucleus in the brain, the larval antennal center (LAC). 4. The responses of LAC projection neurons and higher-order protocerebral interneurons to a given odor were more consistent than the responses of LAC local interneurons. 5. The LAC appears to be functionally subdivided, as both local and projection neurons had arborizations in specific parts of the LAC, but none had dendrites throughout the LAC. 6. The mushroom bodies and the lateral protocerebrum contain neurons that respond to olfactory stimulation.

Animals↗
PubMed1990

Dung beetles, Onthophagus spp., as potential transport hosts of feline coccidia.

Cockroaches and filth-flies have been known to be transport hosts of Toxoplasma gondii but the role of dung beetles as the carrier of coccidian oocysts is not known. We attempted to clarify the role of dung beetles (Onthophagus spp.) as the transport host of feline coccidia including Toxoplasma. Toxoplasma oocysts were found in the feces of the beetles until day 3 after the insects were exposed to cat feces mixed with the oocysts. Furthermore, oocysts on the body surface of beetles were not easily detached but remained infective for a prolonged period of time. Infective dung beetles may contaminate the water with infective oocysts passed in their feces when they dropped into the water. In the field survey feline coccidia, Isospora felis and I. rivolta, were detected in dung beetles collected from dog feces; they play an important role in the transmission of feline coccidian oocysts in the field.

Animals↗
PubMed1989

Diagnosis of Fasciola sp. infections in cattle by enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) was evaluated for diagnosis of experimental or naturally occurring Fasciola sp. infections in cattle. The positive rate for the ELISA in calves inoculated with Fasciola metacercariae were 21.1% by 2 weeks postinoculation (PI), 94.6% by 4 weeks PI and 100% by 6-21 weeks PI. The positive rate for the immunodiffusion test (Ouchterlony test) reached 91.7% by 2 weeks PI, however, it dropped to 77.8% by 10 weeks PI. The positive rate for the fecal egg examination was 0% by 10 weeks PI, 77.8% by 12 weeks PI and 100% by 14-21 weeks PI. The practical application of ELISA was tested by using 165 cows raised under field condition. All the 24 cows that were positive both in the fecal egg examination and the Ouchterlony test were ELISA positive. Of the 6 cows that were egg positive and Ouchterlony negative, 5 showed ELISA positive reactions. Of the 27 cows that were egg negative and Ouchterlony positive, 24 were ELISA positive. Of the 108 cows that were egg negative and Ouchterlony negative, 90 were ELISA negative. However, the other 18 cows had ELISA positive reactions. Our results suggested that the ELISA using crude adult antigen was superior to the Ouchterlony test and fecal egg examination for diagnosis of experimental or naturally occurring Fasciola sp. infections in cattle.

Animals↗