Complete genome sequence of the apicomplexan, Cryptosporidium parvum     

Abrahamsen MS  Templeton TJ  Enomoto S  Abrahante JE  Zhu G  Lancto CA  Deng M  Liu C  Widmer G  Tzipori S  Buck GA  Xu P  Bankier AT  Dear PH  Konfortov BA  Spriggs HF  Iyer L  Anantharaman V  Aravind L  Kapur V 《Science (New York, N.Y.)》2004,304(5669):441-445

The apicomplexan Cryptosporidium parvum is an intestinal parasite that affects healthy humans and animals, and causes an unrelenting infection in immunocompromised individuals such as AIDS patients. We report the complete genome sequence of C. parvum, type II isolate. Genome analysis identifies extremely streamlined metabolic pathways and a reliance on the host for nutrients. In contrast to Plasmodium and Toxoplasma, the parasite lacks an apicoplast and its genome, and possesses a degenerate mitochondrion that has lost its genome. Several novel classes of cell-surface and secreted proteins with a potential role in host interactions and pathogenesis were also detected. Elucidation of the core metabolism, including enzymes with high similarities to bacterial and plant counterparts, opens new avenues for drug development.  相似文献   

Inheritance of flower color in Dendranthema grandiflora Tzvelev. (Chrysanthemum morifolium Ramat.) using cultivars and inbreds. I. Plastid pigmentation     

Tim M. Teynor  Peter D. Ascher  R. E. Widmer  J. J. Luby 《Euphytica》1989,42(3):199-207

Summary Progeny from controlled crosses of 28 garden chrysanthemum (Dendranthema grandiflora Tzvelev.) inbreds in various combinations as males with 3 heterozygous cultivars and 10 inbreds as females were evaluated for plastid pigmentation in a series of field and glasshouse environments. Disomic inheritance of a dominant gene, which acts to inhibit pigmentation, best explained the data. However, 1 of 8 families involving a glasshouse cultivar with colorless plastids (Puritan) as female and inbreds with yellow plastids as males deviated significantly from the expected 1:1 ratio. This family consistently exhibited an excess of plants with colorless plastids. Although parent clones and cloned progeny from inbred parents were scored the same in field and glasshouse environments, reevaluation in the field of all 8 Puritan families, first evaluated in a glasshouse environment, revealed phenotypic misclassification apparently due to environmental effects. An excess of plants with colorless plastids appeared in the glasshouse but evaluation of the same genotypes in the field resulted in an excess of plants having yellow plastids. Submerging ray florets in a hot-water bath revealed yellow plastids masked by vacuolar pigments, thus reducing chances of misclassification. The data suggest that evaluation of highly variable families in a single environment can lead to misclassification of plastid pigmentation. However, even with evaluation in 2 or more environments, certain families may exhibit an excess of plants with colorless plastids.  相似文献   

Principles of magnetic resonance imaging and application to the stifle joint in dogs   总被引：1，自引：0，他引：1  

W R Widmer  K A Buckwalter  E M Braunstein  D M Visco  B L O'Connor 《Journal of the American Veterinary Medical Association》1991,198(11):1914-1922

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A COMPARISON OF IOPAMIDOL AND METRIZAMIDE FOR CERVICAL MYELOGRAPHY IN THE DOG     

William R.  Widmer  DVM  MS  William E.  Blevins  DVM  MS  Dan  Cantwell  DVM  MS  James R.  Cook  Jr.  DVM  Dennis B.  Denicola  DVM  PhD 《Veterinary radiology & ultrasound》1988,29(3):108-115

Cervical myelography using iopamidol, a new nonionic contrast medium, was studied in nine dogs. Postmyelographic seizure activity, motor evoked potentials, and rectal temperatures were monitored, and myelographic quality was subjectively evaluated. The results were compared with data from eight dogs that had metrizamide myelography. The iopamidol group had fewer seizures ( p < 0.01) but exhibited no difference in motor evoked potential or rectal temperature recordings. Myelographic quality was similar for iopamidol and metrizamide. The study suggests that iopamidol was less neurotoxic than metrizamide for canine cervical myelography.  相似文献   

Arthroscopic removal of a palmar radial osteochondroma causing carpal canal syndrome in a horse.     

K R Squire  S B Adams  W R Widmer  R W Coatney  C Habig 《Journal of the American Veterinary Medical Association》1992,201(8):1216-1218

A 5-year-old Arabian stallion with moderate effusion in the right carpal canal and intermittent lameness in this limb was diagnosed to have an osteochondroma projecting from the distal portion of the radius into the carpal canal. oral phenylbutazone treatment over the next 3 years allowed the stallion to continue its show career. Right forelimb lameness returned at that time, and ultrasonography revealed the osteochondroma impinging on the dorsal surface of the deep digital flexor tendon. The owner elected to have the osteochondroma surgically removed. The horse was anesthetized, and the carpal sheath was distended with balanced polyionic solution. A 4-mm arthroscope was inserted into the carpal sheath, and the osteochondroma projecting into the sheath was identified. The osteochondroma was removed by use of a Ferris-Smith bone rongeur, which was inserted into the carpal sheath through a stab incision over the osteochondroma. The effusion in the carpal sheath and the lameness resolved by 2 months, and the horse was returned to training 4 months after surgery.  相似文献   

Evidence of soft-mode quantum phase transitions in electron double layers     

V Pellegrini  A Pinczuk  BS Dennis  AS Plaut  LN Pfeiffer  KW West 《Science (New York, N.Y.)》1998,281(5378):799-802

Inelastic light scattering by low-energy spin-excitations reveals three distinct configurations of spin of electron double layers in gallium arsenide quantum wells at even-integer quantum Hall states. The transformations among these spin states appear as quantum phase transitions driven by the interplay between Coulomb interactions and Zeeman splittings. One of the transformations correlates with the emergence of a spin-flip intersubband excitation at vanishingly low energy and provides direct evidence of a link between quantum phase transitions and soft collective excitations in a two-dimensional electron system.  相似文献   

Effect of body position on electrocardiographic recordings in dogs     

JA Stern  KW Hinchcliff  PD Constable 《Australian veterinary journal》2013,91(7):281-286

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Usefulness of a half-fourier acquisition single-shot turbo spin-echo pulse sequence in identifying arachnoid diverticula in dogs     

Seiler GS  Robertson ID  Mai W  Widmer WR  Suran J  Nemanic S  Lamb CR  Lang J  Johnson JL  Thrall DE 《Veterinary radiology & ultrasound》2012,53(2):157-161

Single-shot turbo spin-echo sequences are heavily T2-weighted sequences that are exceptionally well suited to evaluate the subarachnoid space. In the T2-weighted fast spin-echo sequences that are used routinely in spinal magnetic resonance (MR) imaging, the subarachnoid space is not well differentiated from the surrounding epidural fat, which could lead to decreased detection of lesions of the subarachnoid space such as arachnoid diverticula. Our purpose was to determine the added value of a single-shot turbo spin-echo sequence in identifying cystic lesions of the subarachnoid space in dogs. MR images of six dogs with a confirmed arachnoid diverticulum and 24 dogs with other spinal disease were included. Six observers were asked to interpret only T2-weighted images initially, and in a second session, T2-weighted and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences. The MR images were anonymized, and no signalment, history, or clinical information was provided. Without the HASTE sequences, 25% of arachnoid diverticula were identified. Adding the HASTE sequence increased the diagnosis of arachnoid diverticulum to 52.8%. The resulting difference, after adding the HASTE sequence, of 27.8% was statistically significant (P = 0.002). No false-positive diagnoses of arachnoid diverticulum were made with either sequence. Although sensitivity in this study was likely artificially low, the significantly increased detection rate of arachnoid diverticula when using HASTE imaging indicates that this sequence is a valuable addition to MR imaging protocols for the canine spine.  相似文献   

Effect of methoprene on the progeny production of Tribolium castaneum (Coleoptera: Tenebrionidae)     

Leanage KW Wijayaratne  Paul G Fields  Frank H Arthur 《Pest management science》2012,68(2):217-224

BACKGROUND: Tribolium castaneum (red flour beetle) is a serious insect pest of stored products around the world. Current control measures for this species have several limitations: loss of registration of insecticides, insecticide resistance and consumer concerns about chemical residues in food. The objective of this study was to determine whether methoprene affects progeny production of T. castaneum. Late‐instar larvae or young adults were exposed to methoprene‐treated wheat, and progeny production was determined. The pairing of male and female adults was performed as untreated × untreated, treated × untreated or treated × treated, to study sex‐based effects. RESULTS: There were three outcomes to late‐instar larvae held on methoprene‐treated wheat kernels (0.001 and 0.0165 ppm): (1) failure to emerge as an adult; (2) emergence as an adult, and almost no offspring produced; (3) emergence as an adult and normal production of offspring. Male larvae were more susceptible to methoprene than female larvae. In contrast, young adults exposed to methoprene (1.67–66.6 ppm) showed no reduction in offspring production. CONCLUSION: Methoprene concentrations will decline with time following its application. However, this research indicates that methoprene can still reduce populations of T. castaneum by reducing their progeny production, even if adults emerge. Copyright © 2011 Society of Chemical Industry  相似文献   

Detection of synovial macrophages in the joint capsule of dogs with naturally occurring rupture of the cranial cruciate ligament     

Klocke NW  Snyder PW  Widmer WR  Zhong W  McCabe GP  Breur GJ 《American journal of veterinary research》2005,66(3):493-499

OBJECTIVE: To test the hypotheses that the densities of macrophages in the synovial membranes and capsules of stifle joints in dogs with ruptured cranial cruciate ligaments are greater than those of normal joints and that those densities in affected joints are positively correlated with the chronicity and severity of the disease. ANIMALS: 17 dogs with naturally occurring rupture of the cranial cruciate ligament and 5 healthy control dogs. PROCEDURE: All dogs underwent orthopedic and radiographic evaluations. In affected dogs, duration of clinical signs was used as an indicator of disease chronicity and the severity of osteoarthritis in the stifle joint was determined radiographically. Joint capsule specimens were evaluated histologically; macrophages, interleukin-6, and tumor necrosis factor-alpha were identified by use of immunocytochemical techniques. RESULTS: Compared with unaffected joints, macrophage density was increased in all affected joints. Duration of disease was significantly associated with radiographic severity of osteoarthritis and synovial macrophage density. Synovial macrophage density was significantly associated with severity of osteoarthritis and with the presence of interleukin-6 and tumor necrosis factor-a. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that synovial macrophages may be involved in the development of pathologic changes (including osteophyte formation) in the stifle joints of dogs with osteoarthritis secondary to rupture of the cranial cruciate ligament. Determination of the importance of synovial macrophages in the development of changes in osteoarthritic joints may result in new treatment strategies that involve elimination of the deleterious effects of those cells.  相似文献