Luteinizing hormone-releasing activity in hypophysial stalk blood and elevation by dopamine   总被引：2，自引：0，他引：2  

I A Kamberi  R S Mical  J C Porter 《Science (New York, N.Y.)》1969,166(903):388-390

Pituitary halves incubated in pituitary stalk plasma release more luteinizing hormone than their opposite halves incubated in plasma from peripheral blood. Glands incubated in stalk plasma from dopamine-treated rats release more luteinizing hormone than glands incubated in stalk plasma from untreated controls. Luteinizing hormone-releasing activity in stalk plasma may be due to the luteinizing hormone-releasing factor, and the secretion of luteinizing hormone-releasing factor may be controlled by a dopaminergic mechanism.  相似文献   

A NEW PRESIDENT FOR THE HARVARD APPARATUS COMPANY,INC     

Porter WT 《Science (New York, N.Y.)》1944,99(2580):471-472

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Evidence for biased gene conversion in concerted evolution of ribosomal DNA   总被引：31，自引：0，他引：31  

D M Hillis  C Moritz  C A Porter  R J Baker 《Science (New York, N.Y.)》1991,251(4991):308-310

Concerted evolution is the production and maintenance of homogeneity within repeated families of DNA. Two mechanisms--unequal crossing over and biased gene conversion--have been the principal explanations of concerted evolution. Concerted evolution of ribosomal DNA (rDNA) arrays is thought to be largely the result of unequal crossing over. However, concerted evolution of rDNA in parthenogenetic lizards of hybrid origin is strongly biased toward one of two parental sequences, which is consistent with biased gene conversion as the operative mechanism. The apparent gene conversions are independent of initial genome dosage and result in homogenization of rDNA arrays across all nucleolar organizer regions.  相似文献   

THE FIRST FREE-LIVING FRESHWATER JELLYFISH FROM SOUTH AMERICA     

Porter CE  Schmitt WL 《Science (New York, N.Y.)》1942,96(2501):515-516

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Letters to the editor     

Porter TL 《Science (New York, N.Y.)》1969,164(3878):376-377

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Mining in glacier bay monument     

Porter WW 《Science (New York, N.Y.)》1968,161(3836):7-8

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Science Teaching     

Porter WW 《Science (New York, N.Y.)》1958,128(3332):1157-1158

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Effects of solarization of soil on nematode and fungal pathogens at two sites in victoria     

I.J. Porter  P.R. Merriman 《Soil biology & biochemistry》1983,15(1):39-44

The effect of covering soil with transparent polyethylene sheets, known as soil solarization, on the viability of plant pathogens was determined. The treatment was tested in mid-summer on sandy loams in N.W. and S. Victoria. Columns of moist soil were inoculated with one of a variety of pathogens, viz. Fusarium oxysporum, Pythium irregulare, Plasmodiophora brassicae, Sclerotium cepivorum, S. rolfsii, Sclerotinia minor, Verticillium dahliae and the nematodes Macroposthania xenoplax, Meloidogyne javanica, Pratylenchus penetrans and Tylenchulus semipenetrans. Columns were placed vertically in soil, and then treated either for 4 weeks in N.W. Victoria, or 6 weeks in S. Victoria.Preliminary laboratory tests showed that pathogens were killed by temperatures within the range 38–55°C. The relative sensitivities of pathogens to fluctuating soil temperatures were similar at both sites. The most sensitive were the nematodes, and the fungi V. dahliae, S. cepivorum and S. minor, while F. oxysporum, P. irregulare and P. brassicae were the least sensitive. In N.W. Victoria treatment effects were apparent to 26 cm and most pathogens were not recovered from 0 to 11 cm. In S. Victoria treatment effects were apparent to a depth of 16cm and most pathogens were not recovered from 0 to 6cm.  相似文献   

A COMPARISON OF MANUAL AND AUTOMATIC ULTRASOUND-GUIDED BIOPSY TECHNIQUES     

FREDRIK E. HOPPE  DVM  PHD  DAVE A. HAGER  DVM    PAUL W. POULOS  JR.  DVM PHD  STINA EKMAN  DVM    P. G. LINDGREN  MD  PHD 《Veterinary radiology & ultrasound》1986,27(4):99-101

A manual, ultrasound-guided biopsy technique was compared to a new automatic method using a new biopsy device. The liver and the left kidney of 10 dogs were biopsied using the two methods. The specimens from the biopsies were compared for size and quality. Results demonstrate that larger and higher quality samples were obtained with the new automatic method.  相似文献   

REGIONAL BINDING INDEX OF THE RADIOLABELED SELECTIVE 5-HT2A ANTAGONIST ¹²³I-5-I-R91150 IN THE NORMAL CANINE BRAIN IMAGED WITH SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY     

K. Peremans  DVM  K. Audenaert  MD  PHD  F. Coopman  DVM  F. Jacobs  PHD  F. Dumont  PHD  G. Slegers  PHD  F. Verschooten  DVM  H. Van Bree    DVM  PHD  J. Mertens  PHD  R. Dierckx  MD  PhD 《Veterinary radiology & ultrasound》2003,44(3):344-351

The pattern of the specific 5-HT2A (5-hydroxytryptamine 2A receptor) antagonist 123I-5-I-R91150 was measured in 10 healthy dogs without neurologic and behavior abnormalities. Eight cortical regions (left and right fronto-, temporo-, parieto-, and occipitocortical area), one global subcortical region (including the thalamic system) were compared with a reference region lacking receptors; that is, the cerebellum. The 123I labeled radioligand was injected intravenously 100-200 minutes before acquisition. Both transmission and emission data were obtained with a triple head gamma camera equipped with high-resolution fanbeam collimators. The emission data were corrected for scatter and attenuation. To delineate different cerebral regions more accurately, the regions of interest (ROI) defined in a former study on brain perfusion measured with 99mTc-ethyl cysteinate dimer (ECD) in the same dogs were used. The co-registration of the 99mTc-ECD and the 123I-5-I-R91150, obtained from each dog, was realized with the help of corresponding transmission maps. By normalizing each regional cerebral activity to the activity observed in the cerebellum, the regional radioactivity (binding index) could be relatively quantified. Highest brain uptake was noted in the frontocortical brain areas (right: 1.85, left: 1.89), followed by the temporocortical region (right: 1.58, left: 1.56). Least uptake was noted in the more caudal and middle brain regions [occipito- (right: 1.46, left: 1.41), parietocortical (right: 1.30, left: 1.26), and striatal region (1.19)]. No gender nor age influence was noted in this series. The 123I labeled serotonin-2A receptor ligand seems to have similar cortical binding in the normal canine brain, as shown in humans and other animal species. A frontocortical to occipitocortical (rostrocaudal) binding index gradient was identified within the dog, which has not been seen in imaging studies from humans and other animal species. The significance of these results will need further investigation. This normative data can be used to compare regional brain uptake of the 123I-radioligand to dogs with behavioral disorders related to the serotonergic system, in future studies.  相似文献