Fluorinated molecule as a tracer: difluoroserotonin in human platelets mapped by electron energy-loss spectroscopy

The intracellular distribution of fluorine has been delineated in human platelets incubated with 4,6-difluoroserotonin, utilizing a scanning-transmission electron microscope equipped with an energy-loss spectrometer. Discrete intracellular structures corresponding in location to dense bodies contained high concentrations of fluorine. Electron energy-loss spectroscopy, which apparently can detect less than 10(-20) gram of fluorine in an area of 10 square nonometers, can thus localize fluorinated tracer molecules with biological activity.     

水稻组织培养中Tos17诱发体细胞无性系变异纯合体筛选技术初探

利用PCR技术对从日本引进的Tos17插入水稻极限糊精酶基因变异体后代进行了插入位点鉴定和纯合体筛选分析。结果表明,利用Tos17末端2 6bpDNA序列和插入位点上下游各2 0 0bp和30 0bp处的目标基因序列片段设计引物,可以有效地进行Tos17插入突变纯合体筛选,为突变体的进一步利用提供了分子依据。     

Comparison of quantitative immunoturbidimetric and semiquantitative latex‐agglutination assays for D‐dimer measurement in canine plasma

Background: D‐dimer measurement in dogs is considered the most reliable test for detecting disseminated intravascular coagulation or thromboembolism. Objectives: The purposes of this study were to compare 2 D‐dimer assays, a quantitative immunoturbidimetric and a semiquantitative latex agglutination assay, and to assess the effect of hemolysis and storage conditions on D‐dimer concentration using the quantitative assay. Methods: The immunoturbidimetric assay was validated using canine citrated plasma samples containing different concentrations of D‐dimer. The effect of storage at various temperatures and times was assessed. Hemolysis was produced by adding lysed RBCs to the samples for a final hemoglobin concentration of 0.35 g/dL. Results: For clinically relevant values (>250 μg/L), intra‐assay and interassay coefficients of variation were 6.8% and 7.2%. The assay was linear (r²=1.00), and the tests had good agreement (κ=0.685, P<.001). Storage at 4 °C and ?20 °C and hemolysis had no significant effect on D‐dimer concentrations. In hemolyzed samples stored at room temperature for ≥48 hours, fine clots were noted and often resulted in falsely increased D‐dimer concentrations. Conclusions: Our findings suggest that the immunoturbidimetric assay validated in this study is reliable and accurate for the measurement of D‐dimer in canine plasma. Samples can be stored for up to 1 month at ?20 °C and moderate hemolysis does not significantly affect the D‐dimer concentration in frozen or refrigerated samples.     

ABCB1-1Δ (MDR1-1Δ) genotype is associated with adverse reactions in dogs treated with milbemycin oxime for generalized demodicosis

Twenty-two dogs diagnosed with generalized demodicosis were treated with milbemycin oxime (MO) because of poor response to previous therapies or because the dog was a breed known to be susceptible to ivermectin toxicosis. Fifteen of the 22 dogs were herding breeds. Doses of MO ranged from 1.0 to 2.2 mg kg⁻¹ day⁻¹ per os. Cheek swab samples were obtained in order to determine each dog's ABCB 1 genotype. Adverse drug reactions were recorded for each dog by the owners and/or veterinarians. The ABCB 1-1Δ genotype was significantly associated with the development of an adverse reaction (neurological toxicity) after treatment with MO. None of the 19 dogs with the wild-type ABCB1 allele experienced adverse reactions, whereas two dogs homozygous for the ABCB1-1Δ mutation developed ataxia. Assessing the ABCB1-1Δ genotype prior to MO administration may prevent neurological toxicity in these patients.     

Variability in the yield of benzophenanthridine alkaloids in wildcrafted vs cultivated bloodroot (Sanguinaria canadensis L.)

Populations of bloodroot [Sanguinaria canadensis L. (Papaveraceae)] are found throughout the eastern forests of North America, with particular abundance in the southern Appalachian Mountains. Increasingly, it is finding use in Europe as a nonantibiotic animal feed supplement to promote weight gain. As efforts to cultivate this herb are underway, there is a need to understand the effect of agronomic permutations on both the dry mass rhizome yield and the yield of benzophenanthridine alkaloids. Month-to-month variability of the concentration of the alkaloids sanguinarine and chelerythrine in both cultivated and wildcrafted bloodroot was examined. The alkaloid yield was consistently higher, but more variable, in wildcrafted plants. On average, cultivated rhizomes were both larger and more consistently sized than those that were wildcrafted. The concentration of a suite of trace elements was measured in soil that was collected concomitantly with each plant accession. Differences in element profiles were compared against alkaloid yields.     

Feline calicivirus: a neglected cause of feline ocular surface infections?

Objective To investigate the prevalence of feline calicivirus (FCV) infection in relation to ocular surface lesions in cats with upper respiratory tract diseases (URTD). Animals studied Ninety‐nine cats with ocular surface infection and symptoms or recent history of URTD were examined at various rescue shelters and hospitals. Procedure A complete general and ophthalmic examination was performed including Schirmer tear test, slit‐lamp biomicroscopy, fluorescein and lissamine green staining. Clinical and ocular symptoms were scored and recorded. Conjunctival samples were collected using a cytobrush, and nucleic acid extraction using RT‐PCR was carried out to analyze for the presence of various infectious agents. Results RT‐PCR detected either FCV, feline herpes virus type 1 (FHV‐1), Chlamydophila felis or Mycoplasma spp. in 63/99 samples. 30/63 samples were positive for FCV, 23/63 for C. felis, 21/63 for Mycoplasma spp., and 16/63 for FHV‐1. Out of the 30 FCV‐positive samples, 11 were positive only for FCV and in 19 samples FCV was seen in combination with other agents. FCV infection was highest in animals examined at the rescue centers and in the age group of 0–2 months. Erosive conjunctivitis was an important ocular finding. Oral ulcers were detected in all FCV‐infected cats. Conclusion Results indicate that FCV is highly prevalent in cats with URTD either as a sole infectious agent or in combination with other pathogens and therefore is a potential cause for ocular surface lesions during the URTD.