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71.
A commercial methylcellulose culture medium, with and without the addition of recombinant bovine granulocyte colony-stimulating factor (rbG-CSF), was utilized for culturing bovine bone marrow cells in a colony-forming unit assay. Bone marrow mononuclear cells were isolated and cultured in a commercial methylcellulose-based medium containing several recombinant human cytokines. Cultures were prepared with and without 100 ng/mL of rbG-CSF. The size and mean number of colonies per plate from culture days 3 to 9 were compared. We concluded that bovine bone marrow colony growth was supported by this culture medium. The addition of rbG-CSF yielded larger and more numerous colonies. There were significantly more colonies on day 3 (P < 0.001), day 4 (P < 0.001), and day 5 (P = 0.03) with rbG-CSF. Both culture media had the highest colony counts on day 5.  相似文献   
72.
The purpose of this study was to investigate the effects of isolates of noncytopathic type 2 Bovine viral diarrhea virus (ncpBVDV-2) of high and low virulence on the proliferation of bone marrow progenitor cells. Holstein calves 6 to 7 mo old and BVDV-na?ve were inoculated intranasally with a BVDV isolate of high virulence (HV24515), a BVDV isolate of low virulence (LV11Q), or uninfected cell culture medium. Serial bone marrow and peripheral blood samples were collected before and after inoculation. Bone marrow mononuclear cells (BMMCs) were isolated and cultured for 5 d, and the mean number of colony-forming unit-granulocyte-macrophage (CFU-GM) colonies was determined. Tritiated (3H)-thymidine uptake by BMMCs was determined to indicate overall proliferative capacity. Virus isolation was done on concurrent samples of BMMCs and peripheral blood. Virus was isolated from BMMCs and peripheral blood buffy-coat cells as early as day 2 or 3 after inoculation. Neutropenia developed in both groups inoculated with a BVDV isolate. However, in the calves given LV11Q, neutrophil counts rebounded earlier in response to increased proliferation of BMMCs, whereas the response was delayed in calves given HV24515. Thymidine uptake was significantly increased (P = 0.0047) in BMMCs after inoculation compared with before inoculation in the calves given LV11Q but not in those given HV24515 or in the control calves. The median number of CFU-GM colonies was significantly decreased (P = 0.0164) after inoculation compared with before inoculation in the calves given HV24515, whereas there was no significant difference in the calves given LV11Q or in the control calves. The data support the hypothesis that the prolonged neutropenia observed in calves given HV24515 results at least in part from decreased proliferative capacity of bone marrow progenitor cells.  相似文献   
73.
74.
The purpose of this study was to determine the contents of three forms of vitamin K [phylloquinone, dihydrophylloquinone, and menaquinone-4 (MK-4)] in representative samples (including different samples within the same food category) of meat (n = 128), dairy and eggs (n = 24), and fast foods (n = 169) common to the U.S. diet. The findings of our analysis indicate that no single food item in these categories is a rich dietary source of any one form of vitamin K. However, these foods are often consumed in large quantities; hence, they may be of importance in overall contribution to total vitamin K intake. The presence of MK-4 in meat, eggs, and dairy foods could be important as physiologic functions unique to MK-4 are identified.  相似文献   
75.
Neuropeptides, critical brain peptides that modulate animal behavior by affecting the activity of almost every neuronal circuit, are inherently difficult to predict directly from a nascent genome sequence because of extensive posttranslational processing. The combination of bioinformatics and proteomics allows unprecedented neuropeptide discovery from an unannotated genome. Within the Apis mellifera genome, we have inferred more than 200 neuropeptides and have confirmed the sequences of 100 peptides. This study lays the groundwork for future molecular studies of Apis neuropeptides with the identification of 36 genes, 33 of which were previously unreported.  相似文献   
76.
In principle, the spin-? plutonium-239 ((239)Pu) nucleus should be active in nuclear magnetic resonance spectroscopy. However, its signal has eluded detection for the past 50 years. Here, we report observation of a (239)Pu resonance from a solid sample of plutonium dioxide (PuO(2)) subjected to a wide scan of external magnetic field values (3 to 8 tesla) at a temperature of 4 kelvin. By mapping the external field dependence of the measured resonance frequency, we determined the nuclear gyromagnetic ratio (239)γ(n)(PuO(2))/2π to be 2.856 ± 0.001 megahertz per tesla (MHz/T). Assuming a free-ion value for the Pu(4+) hyperfine coupling constant, we estimated a bare (239)γ(n)/2π value of ~2.29 MHz/T, corresponding to a nuclear magnetic moment of μ(n) ≈ 0.15μ(N) (where μ(N) is the nuclear magneton).  相似文献   
77.
78.
Canine generalized demodicosis (CGD) is a skin disease with distinct breed predispositions. Secondary bacterial infections are common. Dogs typically receive miticidal therapy in combination with antibacterial treatment. Whether antibiotics influence the duration of acaricidal therapy is unknown at the moment. There is also debate over how common short-tailed Demodex mites occur in demodicosis. This study evaluated the influence of systemic antibiotics on the course of CGD, the occurrence of short-tailed Demodex mites in demodectic dogs and the influence of furunculosis on treatment outcome. Breed predispositions for CGD in Moscow were identified. Fifty-eight dogs were randomly distributed in two groups. Both were treated with ivermectin 600 mcg/kg q24h orally and benzoyl peroxide shampoo weekly. The dogs in one group (AB) were additionally treated with systemic antibiotics for at least 1 month, dogs in the other group (NAB) were not. Monthly examinations, skin scrapings and impression smears were performed. Prior to the study there was no difference in clinical severity, presence of pyoderma and mite numbers between groups. There was no significant difference in duration until first negative skin scrapings and resolution of bacterial infection. In dogs with furunculosis the number of the mites was significantly higher than in dogs without furunculosis but the duration until microscopic remission albeit longer, was not significantly different. Short-tailed Demodex mites were found in 25% of the cases. Pugs and English Bulldogs were predisposed. Based on these results, systemic antibiotics may not impact as much as previously thought on the actual success of CGD treatment.  相似文献   
79.
80.
Kinetics and mechanism of cymoxanil degradation in buffer solutions   总被引:1,自引:0,他引:1  
The kinetics and mechanism(s) of the hydrolytic degradation of a compound are needed to evaluate a compound's abiotic degradation in the environment. In this paper, the hydrolysis of cymoxanil [2-cyano-N-[(ethylamino)carbonyl]-2-(methoxyimino) acetamide] was investigated in dark sterile aqueous solutions under a variety of pH conditions (pH 2.8-9.2) and temperatures (15-50 degrees C). Hydrolysis of cymoxanil was described by first-order kinetics, which was dependent on pH and temperature. Cymoxanil degraded rapidly at pH 9 (half-life = 31 min) and relatively slowly at pH 2.8 (half-life = 722 days). The effect of temperature on the rate of cymoxanil degradation was characterized using the Arrhenius equation with an estimated energy of activation of 117.1 kJ mol(-)(1). An increase in temperature of 10 degrees C resulted in a decrease in half-life by a factor of approximately 5. Three competing degradation pathways are proposed for the hydrolysis of cymoxanil, with two of the pathways accounting for approximately 90% of cymoxanil degradation. These two pathways involved either initial cyclization to 1-ethyldihydro-6-imino-2,3,5(3H)-pyrimidinetrione-5-(O-methyloxime) (1, Figure 1) or direct cleavage of the C-1 amide bond to form cyano(methoxyimino) acetic acid (7). The third pathway of degradation involved initial cyclization to 3-ethyl-4-(methoxyimino)-2,5-dioxo-4-imidazolidinecarbonitrile (8), which rapidly degrades into 1-ethyl-5-(methoxyimino)-2,4-imidazoline-2,4-dione (9). All three pathways eventually lead to the formation of the polar metabolite oxalic acid.  相似文献   
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