Molecular dynamics of heterochromatin protein 1beta, HP1beta, during mouse preimplantation development     

Yamazaki T  Kobayakawa S  Yamagata K  Abe K  Baba T 《The Journal of reproduction and development》2007,53(5):1035-1041

To elucidate the molecular dynamics of HP1beta in mouse preimplantation embryos, we examined the localization, dynamics, and mobility of HP1beta in the (pro)nucleus by live cell imaging. Time-lapse observation revealed that the chromatin association of HP1beta is regulated in a cell cycle-dependent manner. HP1beta was localized in the interphase nucleus and was dynamically dissociated from the nucleus during the metaphase stage. The HP1beta assembly and clustered heterochromatin structure were both found in the nuclei of 2-cell and later-stage embryos. Moreover, fluorescent recovery after photobleaching analysis implied that HP1beta is more freely mobile in the pronucleus of the 1-cell embryo than in the 4-cell nucleus. These results suggest that the chromatin configuration may be regulated by the stability and mobility of chromatin-associated proteins including HP1beta during early embryonic stages.  相似文献   

Establishment of a Model of Spontaneously-Running-Tokushima-Shikoku Rats with Left Atrial Thrombosis     

Takamasa Ohnishi  Fumiko Hisaoka  Masaki Morishima  Akira Takahashi  Nagakatsu Harada  Kazuaki Mawatari  Hidekazu Arai  Emiko Yoshioka  Satomi Toda  Izumi Keisuke  Yutaka Nakaya 《Journal of toxicologic pathology》2014,27(1):51-56

Studies that investigate the underlying mechanisms of disease and treatment options typically require the use of a suitable animal model. Few suitable animal models exist for left atrial thrombosis. Here, we demonstrated that the Spontaneously-Running-Tokushima-Shikoku (SPORTS) rat — a Wistar strain known for its running ability—is predisposed to the development of thrombi in the left atrium. We investigated the incidence of left atrial thrombosis in male (n = 16) and female (n = 17) SPORTS rats and observed organized atrial thrombosis in 57% and 38% of males and female rats, respectively. In the male rats, systolic blood pressures and heart rates were significantly higher in SPORTS rats than in control Wistar rats. We could not find any evidence of arrhythmias, such as atrial fibrillation, during electrocardiographic examination of SPORTS rats. We believe that the SPORTS rat could serve as a new research model for left atrial thrombosis; further, it may be suitable for research investigating the development of new antithrombotic approaches for the control of atrial thrombosis or familial thrombophilia in humans.  相似文献   

Mapping genes for deep-seeding tolerance in barley     

Hidekazu Takahashi  Kazuhiro Sato  Kazuyoshi Takeda 《Euphytica》2001,122(1):37-43

Deep-seeding tolerance, the emergence of seedlings from deep seeded conditions, is involved in stand establishment in semi-arid regions, where the soil surface is too dry for seed germination. Genes determining deep-seeding tolerance in barley were mapped using two doubled haploid populations derived from the following crosses: Harrington × TR306 (H/T)and Step toe × Morex (S/M). Significant quantitative trait loci (QTLs) for deep-seeding tolerance were found in each population. Two QTL sex plained 40% of the phenotypic variation in the H/T population and one QTL (S/M) 8% of the total phenotypic variance. Multiple QTLs accounting for coleoptile length and first internode length were detected in both populations. In the H/T population, there were coincident QTLs for deep-seeding tolerance, coleoptile length and first internode length on the long arm of chromosome 5H. These QTLs correspond with previously reported QTLs for abscisic acid and gibberellic acid response. QTL coincidence may be due to the pleiotropic effects of alleles at a single locus. This information may be useful for breeding programs manipulating morphological and physiological traits in order to develop varieties for semi-arid regions. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Periodic signaling controlled by an oscillatory circuit that includes protein kinases ERK2 and PKA   总被引：1，自引：0，他引：1  

Maeda M  Lu S  Shaulsky G  Miyazaki Y  Kuwayama H  Tanaka Y  Kuspa A  Loomis WF 《Science (New York, N.Y.)》2004,304(5672):875-878

Self-regulating systems often use robust oscillatory circuits. One such system controls the chemotactic signaling mechanism of Dictyostelium, where pulses of adenosine 3',5'-monophosphate (cAMP) are generated with a periodicity of 7 minutes. We have observed spontaneous oscillations in activation of the mitogen-activated protein (MAP) kinase ERK2 that occur in phase with peaks of cAMP, and we show that ERK2 modulates cAMP levels through the phosphodiesterase RegA. Computer modeling and simulations of the underlying circuit faithfully account for the ability of the cells to spontaneously generate periodic pulses during specific stages of development. Similar oscillatory processes may occur in cells of many different species.  相似文献   

Mortierella wolfii keratomycosis in a horse     

Wada S  Ode H  Hobo S  Niwa H  Katayama Y  Takatori K 《Veterinary ophthalmology》2011,14(4):267-270

Purpose To describe a case of superficial keratomycosis caused by Mortierella wolfii (M. wolfii) in a horse. Methods A thoroughbred filly was presented with painful right eye of 2 days’ duration. A superficial corneal ulcer was observed ventrally together with multifocal punctuate opacities axially. Samples were collected by swabbing and scraping the ulcerated lesion and submitted for microbiologic and cytologic examination. Results Microscopic evaluation of debrided corneal tissue revealed the presence of nonseptate fungal hyphae, and culture of a corneal swab yielded fungal growth. Medical treatment with topical antifungal, antibiotic and autogenous serum and systemic anti‐inflammatory resolved the problem within 2 weeks. Conclusions Cytologic evaluation of a corneal scraping was useful to make a clinical diagnosis of keratomycosis. Based on the mycological characteristics, the fungus isolated from the corneal lesion was identified as M. wolfii. To the authors’ knowledge, this is the first case report of equine keratomycosis associated with this fungus, although the organism is known to infect various organs of cattle.  相似文献   

Acquisition of quinolone resistance and point mutation of the gyrA gene in Campylobacter jejuni isolated from broilers and in vitro-induced resistant strains   总被引：1，自引：0，他引：1  

Chuma T  Maeda T  Niwa H  Okamoto K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(2):155-160

A dramatic rise in the number of resistant Campylobacter to quinolones has been documented in human patients and domestic animals. In this study, the mechanism of acquisition of quinolone resistance was studied by detecting point mutations in the gyrA gene of Campylobacter strains obtained from broilers and strains with in vitro-induced resistance. The minimal inhibitory concentrations (MICs) of norfloxacin (NFLX) and ofloxacin (OFLX) for the strains that had no point mutation were slightly increased from the source strain (Campylobacter jejuni ATCC 33560). The MICs of nalidixic acid (NA), NFLX, and OFLX for the strains that had the point mutation at Thr-86 were 100 or 200 microg/ml, 50 microg/ml, and 25 microg/ml, respectively. The MIC of NA for the strain that had a point mutation at Asp-90 higher than those for the strains that had the point mutation at Thr-86, but the MICs of NFLX and OFLX were relatively lower than those for the strains that had point mutation at Thr-86. These findings suggest that the degree of antimicrobial resistance against NA, NFLX, and OFLX in the in vitro-induced C. jejuni strains was associated with the location of the point mutation in gyrA. On the other hand, a point mutation in all seven resistant strains isolated from broilers was located only at Thr-86, while the MICs of the three quinolones varied in each wild strain. This suggests that another mechanism might also be involved in the acquisition of quinolone resistance in C. jejuni wild strains.  相似文献   

A case of canine gastrinoma     

Fukushima R  Ichikawa K  Hirabayashi M  Yamagami T  Koyama H  Hirose H  Uchino T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(8):993-995

The dog of this case was a 10-year-old Shih Tzu with refractory vomiting, diarrhea and anorexia. Endoscopy revealed an unclear at gastric angle, a stenosis at pyloric antrum and congestion in duodenal mucosa. Since abnormal shadows of irregular echo-levels were disclosed by pancreas ultrasonography, serum gastrin level was determined with a suspect of gastrinoma. And an increase of serum gastrin was demonstrated. In addition, postmortem histological examination revealed that the pancreatic cells were positive for gastrin. Based on these findings, the dog was diagnosed as pancreatic gastrinoma.  相似文献   

Establishment of a large-scale purification procedure for purified recombinant bovine interferon-tau produced by a silkworm-baculovirus gene expression system     

Nagaya H  Kanaya T  Kaki H  Tobita Y  Takahashi M  Takahashi H  Yokomizo Y  Inumaru S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(11):1395-1401

We developed a procedure for the large-scale purification of bovine interferon-tau (boIFN-tau) by means of a silkworm-baculovirus gene expression system. Recombinant boIFN-tau (rboIFN-tau) was efficiently produced in the silkworm infected with boIFN-tau cDNA recombinant baculovirus and accumulated in the haemolymph. To establish a purification method suitable for mass production, we tried three crude purification methods, namely, an acidification and neutralization treatment (ANT), silica gel column chromatography (SGCC), and Blue sepharose column chromatography (BSCC) with a combination of Q-sepharose (QSC) and chelating sepharose column chromatographies (CSCC). As a result, the acidification and neutralization treatment was found to be the most efficient and cost effective. With this combination, we obtained 91% pure products. To confirm the applicability of the procedure for mass production, we inoculated 100 silkworms with the recombinant virus, and recovered about 4.55 mg (1.26 x 10(8)U/mg) of 91% pure rboIFN-tau by means of a combination of the ANT, followed by QSC and CSCC.  相似文献   

A nucleotide mutation associated with fluoroquinolone resistance observed in gyrA of in vitro obtained Rhodococcus equi mutants   总被引：1，自引：0，他引：1  

Niwa H  Hobo S  Anzai T 《Veterinary microbiology》2006,115(1-3):264-268

In this study, the quinolone resistance-determining region (QRDR) in gyrA and gyrB of in vitro fluoroquinolone-resistant Rhodococcus equi mutants was sequenced. These mutants were selected from four R. equi strains on blood agar plates containing ciprofloxacin or enrofloxacin. Each mutant became 8- to 64 or greater-fold resistant to fluoroquinolones compared with their parent strains. From the results of sequence analysis of QRDR in gyrA and gyrB, a nucleotide mutation of codon GAC for GGC in gyrA was detected in all mutants, but no mutation was observed in gyrB. This mutation leads to amino acid substitution of Asp for Gly in putative GyrA in R. equi. The position of this substitution corresponds to position 87 of GyrA in Escherichia coli. Our results suggest that the mutation of QRDR in gyrA, which was observed in in vitro fluoroquinolone-resistant R. equi mutants in this study, is closely associated with fluoroquinolone resistance.  相似文献   

Evaluation of the clinical efficacy of benazepril in the treatment of chronic renal insufficiency in cats     

Mizutani H  Koyama H  Watanabe T  Kitagawa H  Nakano M  Kajiwara K  King JN 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(5):1074-1079

BACKGROUND: Chronic renal insufficiency (CRI) is a common disease in cats. Angiotensin-converting enzyme inhibitors (ACEI) have beneficial effects in humans with CRI by reducing the loss of protein in the urine and increasing life expectancy. HYPOTHESIS: The ACEI benazepril has beneficial effects on survival, clinical variables, or both as compared with placebo in cats with CRI. ANIMALS: 61 cats with naturally occurring CRI. METHODS: The cats were enrolled into a prospective, randomized, double-blind, placebo-controlled clinical trial. Cats received placebo or 0.5-1 mg/kg benazepril once daily for up to 6 months. RESULTS: Urine protein/urine creatinine ratios were significantly (P < .05) lower with benazepril as compared with placebo at days 120 and 180. Three cats with placebo and 1 cat with benazepril were removed prematurely from the study because of deterioration of CRI or death. Cats were classified into 4 stages of CRI according to the International Renal Interest Society (IRIS) classification scheme. Incidence rates of cats with IRIS classification stage 2 or stage 3 that remained in stage 2 or 3 without progressing to stage 4 were higher with benazepril (93 +/- 5%) as compared with placebo (73 +/- 13%). CLINICAL IMPORTANCE: These results suggest a potential for benazepril to delay the progression of disease, extend survival time, or both in cats with CRI.  相似文献