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Biomedical subjects

T Itami

Publications and source records attributed to T Itami.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of Lancefield group C Streptococcus dysgalactiae isolated from farmed fish.

A Lancefield group C streptococcal (GCS) infection caused by Streptococcus dysgalactiae that is characterized by severe necrotic lesions of the caudal peduncle has been an increasing cause of mortality in farmed fish such as amberjack, Seriola dumerili, and yellowtail, Seriola quinqueradiata, in the southern part of Kyushu, Japan. In this study, enzymatic profiles of GCS strains from fish and mammals were investigated using the API ZYM system, and genotypic characterization of GCS strains was performed using biased sinusoidal field gel electrophoresis (BSFGE). The partial sequence of the 16S-23S rDNA intergenic spacer region of the GCS strain isolates from fish and mammals was also compared. The API ZYM test indicated that it is difficult to differentiate isolates of S. dysgalactiae from fish and animals based on enzymological variations. In the BSFGE analysis, the macrorestriction profiles, which were obtained using SmaI or ApaI as a restriction enzyme, revealed variations between the fish and animal isolates. The partial sequence of the 16S-23S rDNA intergenic spacer region of all the tested fish isolates differed from all mammalian isolates in one or two nucleotides. The possibility of a clonal expansion of S. dysgalactiae strains in farmed fish was also suggested by the BSFGE profiles of fish isolates.

Animals↗
PubMed2005

Loop-mediated isothermal amplification: an emerging technology for detection of fish and shellfish pathogens.

Fish and shellfish diseases are a constant threat to the sustainability and economic viability of aquaculture. Early diagnosis plays a vital role in management of fish and shellfish diseases. Traditionally, various biochemical and serological tests have been used for fish disease diagnosis. However, the time and expertise required for such diagnoses makes it difficult for aquaculturists to easily adopt them under production conditions. Polymerase chain reaction and probe-based nucleic acid detection have become increasingly popular in fish and shellfish diagnostics. Recently, a novel technique called loop-mediated isothermal amplification (LAMP) has been developed, which is highly sensitive and rapid. LAMP has been used for the detection of bacterial, viral, fungal and parasitic diseases in both animal and plants. In aquaculture, LAMP-based detection of pathogens like Edwardsiella tarda, E. ictaluri, Nocardia seriolae, Tetracapsuloides bryosalmonae, white spot syndrome virus and infectious haematopoietic necrosis virus have been reported. In this review, the application of LAMP for the detection of aquaculture-associated pathogens is discussed.

Animals↗
PubMed2004

Improved conception in timed-artificial insemination using a progesterone-releasing intravaginal device and Ovsynch protocol in postpartum suckled Japanese Black beef cows.

The primary objective was to determine the effect of supplemental progesterone, administered via an intravaginal device (CIDR), on conception rates to timed-artificial insemination (timed-AI) in postpartum suckled Japanese Black beef cows treated with the Ovsynch protocol. A secondary objective was to compare the effects of treatments on plasma concentrations of progesterone and estradiol. Cows in the control group (Ovsynch, n=38) received a standard Ovsynch protocol (100 microg GnRH analogue on Day 0, 500 microg PGF2alpha analogue on Day 7, and 100 microg GnRH analogue on Day 9), with AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the treatment group (Ovsynch+CIDR; n=40) received a standard Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Plasma progesterone concentrations were determined on Days 0, 1, 7, 9, 10, and 17 and plasma estradiol-17beta concentrations were determined on Days 7, 9, 10, and 17. The odds ratio for likelihood of conception was 3.29 times greater (P=0.02) in the Ovsynch+CIDR group compared to Ovsynch group. The conception rate was greater (P=0.03) in the Ovsynch+CIDR group than in the Ovsynch group (72.5% versus 47.7%). Insertion of a CIDR device significantly increased plasma progesterone concentrations only on Days 1 and 7 (P<0.001 and P=0.05, respectively), but had no significant effect on plasma estradiol-17beta concentrations. Including a CIDR with the Ovsynch protocol significantly improved conception rates in postpartum suckled Japanese Black beef cows.

Administration, Intravaginal↗
PubMed2004

Lancefield group C Streptococcus dysgalactiae infection responsible for fish mortalities in Japan.

A Lancefield serological group C Streptococcus sp. was isolated from cultured amberjack, Seriola dumerili Risso, and yellowtail, Seriola quinqueradiata Temminck and Schlegel, immunized with Lactococcus garvieae commercial vaccines in Japan. The isolated bacteria were Gram-positive cocci, auto-aggregating in saline, morphologically long chains in growth medium, catalase negative and alpha-haemolytic on blood agar. An almost complete gene sequence of the 16S rDNA of two isolates was determined and compared with that of bacterial strains in the database. The isolates were identified as Streptococcus dysgalactiae based on the results of the 16S rDNA sequence, the bacteriological properties and the Lancefield serological grouping. Oligonucleotide primers specifically designed for the 16S-23S rDNA intergenic spacer region of S. dysgalactiae amplified a gene from all the fish isolates, as well as the type strains alpha-haemolytic S. dysgalactiae subsp. dysgalactiae ATCC430738 and beta-haemolytic S. dysgalactiae subsp. equisimilis ATCC35666, but not those of S. equi ATCC33398, Lactococcus garvieae ATCC43921 and L. garvieae KG9408. The severe necrotic lesions of the caudal peduncle seen in experimentally infected fish were similar to those seen in naturally infected fish.

Animals↗
PubMed2000

Red swamp crawfish (Procambarus clarkii): an alternative experimental host in the study of white spot syndrome virus.

The pathogenicity of white spot syndrome virus (WSSV) for the red swamp crawfish (Procambarus clarkii) was investigated after infection by intramuscular (i.m.) injection and oral route. The cumulative mortality of crawfish injected i.m. with WSSV reached 100% in 5 days. After oral feeding WSSV-infected kuruma shrimp (Penaeus japonicus) muscle tissues to the crawfish the cumulative mortality of this host reached 100% in 11 days. On reinfection trials, all the crawfish fed WSSV-infected crawfish muscle tissues died in 9 days. All the shrimp injected with a filtrate of infected crawfish heart tissues died in 12 days with typical signs of white spot syndrome (WSS). Electron microscopy clearly demonstrated that WSSV propagated in the cells of the crawfish midgut. This study showed that the red swamp crawfish can be used as alternative experimental host in the study of WSSV.

Animals↗
PubMed1999

Primary culture of lymphoid organ cells and haemocytes of kuruma shrimp, Penaeus japonicus.

A primary cell culture system was developed for the cells of lymphoid organ tissue of kuruma shrimp, Penaeus japonicus. Minced tissues of lymphoid organs were seeded and incubated at 30 degrees C in medium 199 supplemented with 20% foetal bovine serum, a salt mixture and a lactalbumin hydrolysate (0.1 g/l). Fibroblast-like cells and epithelioid-like cells survived for 54 days. Cells did not survive after trypsin, collagenase or hyaluronidase treatment used for cell dissociation. Mitogens (Con A, PHA-P, Pokeweed) and insulin did not enhance cell proliferation. When penaeid rod-shaped DNA virus (PRDV) was inoculated into the lymphoid organ cell culture, a cytopathic effect was observed within 8 days. On the other hand, large granular haemocytes that were fractionated using a Percoll continuous density gradient were not infected with PRDV in vitro within 10 days, which was the longest period of haemocyte maintenance.

Animals↗
PubMed1993

Teratogenic phase specificity of butyl benzyl phthalate in rats.

Pregnant rats were given butyl benzyl phthalate (BBP) by gastric intubation at a dose of 0.6, 0.75 or 1.0 g/kg on days 7-9, 10-12 or 13-15 of pregnancy. While treatment with BBP on days 7-9 or 13-15 at doses of 0.75 and 1.0 g/kg was significantly teratogenic, no evidence of teratogenicity was detected when BBP was given on days 10-12. The incidence of malformed fetuses was proportional to the dose of BBP. Treatment on days 7-9 with BBP at doses of 0.75 g/kg and above caused a significant increase in the number of skeletal malformations, such as fusion of the cervical vertebral arches and deformity of the thoracic vertebrae, but neither external nor internal malformations. Treatment on days 13-15 with two higher doses of BBP resulted in a significantly increased incidence of fetuses with external and skeletal malformations such as cleft palate and fusion of the sternebrae. The highest incidence of malformed fetuses occurred after treatment with BBP on days 13-15. It could be concluded that the susceptibility to the teratogenicity of BBP varies with the developmental stage at the time of administration.

Abnormalities, Drug-Induced↗
PubMed1993

Teratogenic evaluation of di-n-butyl phthalate in rats.

Pregnant rats were given di-n-butyl phthalate (DBP) by gastric intubation at a dose of 0, 0.5, 0.63, 0.75 or 1.0 g/kg on days 7-15 of pregnancy. A significant decrease in the maternal body weight gain after treatment with DBP was found at a dose of 0.63 g/kg and above. Maternal death and complete resorption of implanted embryos in all the surviving dams were observed in the 1.0 g/kg group. Significantly increased incidence of postimplantation loss and decreased fetal weight were detected at doses of 0.63 and 0.75 g/kg. The incidence of fetuses with malformations was higher in the 0.63 and 0.75 g/kg groups than in the control group, and the difference was significant in the 0.75 g/kg group. Cleft palate were predominantly observed.

Abnormalities, Drug-Induced↗
PubMed1993

Teratogenic evaluation of p-tert-butylphenol formaldehyde resin (novolak type) in rats following oral exposure.

The teratogenicity of p-tert-butylphenol formaldehyde resin, novolak type, (PTBP-FR) was examined in Wistar rats. Pregnant rats were fed diets containing 0, 2.5, 5 or 10% of PTBP-FR ad libitum from day 6 to day 15 of pregnancy. Maternal toxicity, as evidenced by a decreased maternal body weight gain and food consumption, was observed in the 5 and 10% dose groups. However, treatment-related clinical signs were not observed. No significant reductions in the fetal body or placental weights were observed in any dose group. There were no significant differences in the number of live fetuses, intrauterine deaths (dead fetuses and resorptions), or fetal sex ratios found between the PTBP-FR-treated and control groups. Although external and internal malformations including short tail, dilatation of the cerebral ventricle and the renal pelvis and dextrocardia, and some skeletal variations were observed in fetuses at some groups treated with PTBP-FR, the incidences of these morphological alterations were not statistically different from controls. In conclusion, PTBP-FR administered orally to Wistar rats during days 6-15 of gestation produced no related signs of developmental toxicity.

Abnormalities, Drug-Induced↗
PubMed1992

Effect of period of exposure on the developmental toxicity of butyl benzyl phthalate in rats.

The objective of the present study was to determine if periods of exposure would modify the developmental toxicity of butyl benzyl phthalate (BBP). Pregnant Wistar rats were given BBP at a dose of 2.0% in the diet on days 0-20, days 0-7, days 7-16 or days 16-20 of pregnancy. Food consumption and body weight gain were decreased in the pregnant rats given BBP. All dams given BBP on days 0-20 exhibited complete resorption of all the implanted embryos. Post-implantation loss in the pregnant rats given BBP on days 0-7 or 7-16 was higher than that in the control and pair-fed pregnant rats. No increase in post-implantation loss was found in the pregnant rats given BBP on days 16-20. Pre-implantation loss in the BBP-treated groups was comparable to the control and pair-fed groups. Striking teratogenicity was detected in fetuses of the dams given BBP on days 7-16. Cleft palate and fusion of the sternebrae were predominantly observed. About 95% of the fetuses in this group had cleft palate. The incidence of malformations in this group was significantly and markedly higher than that in the control and pair-fed groups.

Abnormalities, Drug-Induced↗
PubMed1992

Embryolethality and teratogenicity of butyl benzyl phthalate in rats.

Pregnant Wistar rats were given butyl benzyl phthalate (BBP) at a dose of 2.0% in the diet on days 0-20, days 0-11 or days 11-20 of pregnancy. Food consumption and body weight gain were decreased in pregnant rats given BBP. Pre-implantation loss in the BBP-treated groups was comparable to that in the control and pair-fed groups. All dams given BBP on days 0-20 or days 0-11 exhibited complete resorption of all the implanted embryos. No increase in post-implantation loss was found in pregnant rats given BBP on days 11-20. Marked teratogenicity was detected in fetuses of the dams given BBP on days 11-20. Cleft palate and fusion of the sternebrae were predominantly observed. Seventy-two of the 134 fetuses had a cleft palate. The incidence of malformations in this group was significantly and markedly higher than that in the control and pair-fed groups. In conclusion, the administration of BBP during the first and second half of pregnancy produced embryolethality and teratogenicity, respectively.

Abnormalities, Drug-Induced↗
PubMed1992

Susceptible period for the teratogenicity of di-n-butyltin dichloride in rats.

Pregnant rats were given di-n-butyltin dichloride (DBT) by gastric intubation at a dose of 20 mg/kg on days 7-9, 10-12 or 13-15 of pregnancy or at a dose of 20 or 40 mg/kg on day 6, 7, 8 or 9 of pregnancy. While treatment with DBT on days 7-9 was significantly and highly teratogenic, no evidence of teratogenicity was detected when DBT was given on days 10-12 or 13-15. Treatment on day 7 or 8 with both doses of DBT, but neither on day 6 or 9, resulted in an increased incidence of fetuses with malformations. The highest incidence of malformed fetuses occurred after treatment on day 8. The incidence of malformed fetuses was proportional to the dose of DBT. Anomaly of tail, anal atresia, club foot, omphalocele, deformity of the vertebral column, defect of the ribs and anophthalmia or microphthalmia were predominantly observed. It could be concluded that, following maternal exposure to DBT in rats, developing offspring are not susceptible to teratogenic effects of DBT on day 6 and that day 7 is the earliest susceptible period, day 8 is the highest susceptible period and day 9 is no longer a susceptible period for teratogenesis of DBT.

Animals↗
PubMed1992

Teratological assessment of glutaraldehyde in rats by gastric intubation.

Pregnant rats were given glutaraldehyde (GA) by gastric intubation at a dose of 0, 25, 50 or 100 mg/kg on days 6-15 of pregnancy. Maternal toxicity occurred in the 100 mg/kg group as evidenced by a significant increase in maternal death and a significant decrease in maternal body weight gain and food consumption. A significantly lowered fetal weight was also found in the 100 mg/kg group. No significant change induced by GA was detected in the incidence of postimplantation loss. Morphologic examinations of fetuses revealed no evidence of teratogenicity of GA. It could be concluded that GA has no teratogenic effects on rat offspring even at a dose which induced severe maternal toxicity.

Abnormalities, Drug-Induced↗
PubMed1992

Teratogenic evaluation of butyl benzyl phthalate in rats by gastric intubation.

Pregnant rats were given butyl benzyl phthalate (BBP) by gastric intubation at a dose of 0, 0.5, 0.75 or 1.0 g/kg on days 7-15 of pregnancy. In the 0.5 g/kg group, food consumption during the administration period was significantly decreased, but no adverse effect on the embryo-fetus was detected. High maternal lethality and complete resorption of implanted embryos in all the surviving dams were observed in the 1.0 g/kg group. Increased embryo-fetal death and decreased fetal weight were found at a dose of 0.75 g/kg which also caused reductions in maternal body weight gain and food consumption. A significantly and markedly increased incidence of fetal malformations was also detected in the 0.75 g/kg group. Cleft palate, fusion of the sternebrae and dilatation of the renal pelvis were mostly observed.

Abnormalities, Drug-Induced↗
PubMed1992

Teratological assessment of diiodomethyl p-tolyl sulfone in rats.

Pregnant rats were given diiodomethyl p-tolyl sulfone (DIMPTS) at a dose of 0, 0.125, 0.25, 0.5 or 1.0% in the diet on days 6-15 of pregnancy. Maternal body weight gain and food consumption during the administration period were significantly lowered in the 0.25, 0.5 and 1.0% groups. No significant changes induced by DIMPTS were detected in the number of resorptions and dead fetuses, and body weight of live fetuses. Morphological examinations of fetuses revealed no evidence of teratogenesis. It could be concluded that DIMPTS has no teratogenic effects on rat offspring, even at doses which induced maternal toxicity.

Abnormalities, Drug-Induced↗
PubMed1992

[Antipyretic effects of traditional Chinese medicines in bacterial endotoxin-induced febrile rabbits].

The antipyretic effects of oral administration of eight traditional Chinese medicines (dried extracts) were tested in febrile rabbits injected with bacterial pyrogen, lipopolysaccharide (LPS) 0.05 micrograms/kg (i.v.). The traditional Chinese medicines were given 0.6-2 g/10 ml/kg (p.o.) simultaneously with LPS. The most potent antipyretic effect was observed in Dai-jyoki-to (Ta-chen-chi-tang). The moderate antipyretic effects were observed in Toki-syakuyaku-san (Tang-kuei-shao-yao-san) and Syo-saiko-to (Hssiao-chai-hu-tang). Koso-san (Hsiang-su-san), Oren-gedoku-to (Huang-lien-chieh-tu-tan), Gorei-san (Wu-ling-san), Kakkon-to (Ko-ken-tang) and Byakkoka-ninjin-to (Pai-hu-chia-jen-sheng-tang) showed no effects.

Animals↗