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S Erickson

Publications and source records attributed to S Erickson.

At least 55 records · Page 3Linked to original sources
PubMed1991

sRNA of phage phi 29 of Bacillus subtilis mediates DNA packaging of phi 29 proheads assembled in Escherichia coli.

The structural genes of the prohead of phage phi 29 of Bacillus subtilis and a small phi 29 RNA (sRNA) were cloned and expressed in Escherichia coli individually or in combination to study the role of the sRNA in prohead assembly and the mechanism of prohead morphogenesis. The genes coding for the proteins of the scaffold (gp7), the capsid (gp8), the portal vertex (gp10), and the dispensable head fiber (gp8.5) were expressed in E. coli and the gene products were assembled, with and without the presence of the sRNA, into uniform and prolate particles that resembled the typical native phi 29 prohead. No differences in particle size and shape were found between the particles of 7-8-8.5-10 (scaffold-capsid-fiber-portal vertex) and 7-8-8.5-10-RNA (scaffold-capsid-fiber-portal vertex-RNA), suggesting that the phi 29 sRNA was not required for phi 29 prohead assembly. The 7-8-8.5-10 particles produced in E. coli in the absence of phi 29 sRNA were fully competent to package phi 29 DNA in the defined in vitro DNA packaging system by the addition of purified sRNA. Moreover, these DNA-filled heads were assembled into infectious virions in extracts. Without the addition of the sRNA, the 7-8-8.5-10 particles were incompetent while the 7-8-8.5-10-RNA particles were competent in DNA packaging. Bacterial sRNA present in E. coli cannot substitute for the phi 29 sRNA. The assembly of prohead particles in E. coli indicated that host factors unique to B. subtilis were not required. The evidence that the phi 29 sRNA was not required for phi 29 prohead assembly and was not a fixed structural component of the phi 29 prohead favors the conclusion that the phi 29 sRNA is a specific enzyme or morphogenetic factor in DNA packaging.

Bacillus subtilis↗
PubMed1989

Computed tomographic features of esthesioneuroblastoma.

Esthesioneuroblastomas are uncommon neoplasms of the superior nasal cavity originating from olfactory epithelium. High resolution CT features of this neoplasm have not been well studied. Nine cases of esthesioneuroblastoma were reviewed to evaluate findings on high resolution CT. Homogeneous soft tissue masses with relatively uniform enhancement centered in the superior nasal cavity are characteristic. Bony erosion is frequent and usually accompanied by molding of bone. Staging, determined by extension and critical for treatment decisions, is well evaluated by CT.

Adult↗
PubMed1989

Perivascular color artifact: pathologic significance and appearance on color Doppler US images.

A distinctive type of artifactual extravascular assignment of color was identified in 49 color Doppler ultrasound (US) examinations in 43 patients. This artifact appeared as a random localized mixture of red and blue assigned to perivascular soft tissues; the artifact varied with the cardiac cycle, being most prominent in systole and absent or less prominent in diastole. The artifact was seen in 26 patients (32 examinations) at an anastomotic site or stenotic lesion associated with surgically created arteriovenous fistulas for hemodialysis. It was also observed in ten patients with accidental iatrogenic arteriovenous fistulas (renal transplant [n = 6], femoral artery [n = 3], and iliac artery [n = 1]), five with stenotic arteries not associated with arteriovenous fistulas, and two with arterial aneurysms. The authors believe this artifact reflects perivascular tissue vibration caused by turbulent intravascular blood flow. If properly recognized and accurately interpreted, the artifact can be a valuable color Doppler US sign of underlying vascular abnormality.

Aneurysm↗
PubMed1989

Color Doppler ultrasound imaging of lower-extremity venous disease.

A color Doppler ultrasound imaging device was used to evaluate 475 patients with suspected lower-extremity venous thrombosis. Occlusive and nonocclusive femoral and popliteal thrombi were detected in 200 studies (42%). In phase 1 of the study (240 examinations), peripheral augmentation with the use of periodic calf compression was required to show color flow throughout the femoropopliteal venous segment. In phase 2 (235 examinations), with a software upgrade to enhance detectability of slow flow, spontaneous flow could be appreciated in the normal, partly thrombosed, and recanalized femoral popliteal veins without augmentation. Augmentation was often necessary to view tibioperoneal veins. Of the total study group, conventional venography was performed for correlation in 47 patients. In the other patients, clinicians relied on the color Doppler test for the definitive diagnosis of the presence or absence of femoral popliteal venous thrombosis and treated these patients on the basis of the color Doppler test result. In the femoral veins, color Doppler studies and venography agreed in all 12 positive and 35 negative cases. In the popliteal veins, there was agreement in five isolated popliteal thromboses and in 10 femoral popliteal thromboses; there were two false-negative color Doppler studies of isolated popliteal thromboses. In four patients, Doppler studies detected nonocclusive thrombus not evident on venography. Color Doppler imaging is easy to perform and does not require augmentation to view color flow in the femoropopliteal venous segment. Eccentric thrombus and partially canalized thrombus can be shown. Initial experience suggests color Doppler imaging may be useful in the detection of tibioperoneal venous thrombosis.

Femoral Vein↗
PubMed1988

Neovascularity in venous extension of renal cell carcinoma: CT and arteriographic evaluation.

Renal cell carcinoma with venous extension can be evaluated preoperatively using computerized tomography, venography, arteriography, sonography, and magnetic resonance imaging. The spectrum of venous involvement ranges from bland thrombus to tumor with neovascularity. With CT imaging, bland thrombus or tumor thrombus without vivid neovascularity will show a central area of decreased attenuation. Using CT with intravenous bolus technique, thrombus with neovascularity will show attenuation that is isodense with the viable portions of the tumor. This appearance represents the venous extension of tumor thrombus containing a rich bed of neovascularity.

Carcinoma, Renal Cell↗
PubMed1987

A small viral RNA is required for in vitro packaging of bacteriophage phi 29 DNA.

A small RNA of Bacillus subtilis bacteriophage phi 29 is shown to have a novel and essential role in viral DNA packaging in vitro. This requirement for RNA in the encapsidation of viral DNA provides a new dimension of complexity to the attendant protein-DNA interactions. The RNA is a constituent of the viral precursor shell of the DNA-packaging machine but is not a component of the mature virion. Studies of the sequential interactions involving this RNA molecule are likely to provide new insight into the structural and possible catalytic roles of small RNA molecules. The phi 29 assembly in extracts and phi 29 DNA packaging in the defined in vitro system were strongly inhibited by treatment with the ribonucleases A or T1. However, phage assembly occurred normally in the presence of ribonuclease A that had been treated with a ribonuclease inhibitor. An RNA of approximately 120 nucleotides co-purified with the phi 29 precursor protein shell (prohead), and this particle was the target of ribonuclease action. Removal of RNA from the prohead by ribonuclease rendered it inactive for DNA packaging. By RNA-DNA hybridization analysis, the RNA was shown to originate from a viral DNA segment very near the left end of the genome, the end packaged first during in vitro assembly.

Bacillus subtilis↗
PubMed1986

Future Fit: a cardiovascular health education and fitness project in an after-school setting.

Future Fit was developed to provide a low cost, heart health education and fitness program that could be incorporated readily into existing after-school programs with minimal teacher training and nominal expenditures for equipment and supplies. Participants in the 12-week demonstration project were 55 third and fourth grade students enrolled in after-school programs at four sites, randomly assigned to experimental and control conditions. Results indicated significant knowledge gains and changes in knowledge, attitude, and behavior at home. These outcomes suggest health and fitness programming in the after-school setting can be an effective complement to the education provided within the school setting.

Attitude to Health↗
PubMed1986

Reducing distress in pediatric patients undergoing cardiac catheterization.

This project collected data on the use of auditory tapes to reduce acute distress in pediatric patients during cardiac catheterization. Observations by the medical staff as well as patients' subjective experience indicated that the tapes were a useful adjunct in helping young patients tolerate the distress of the medical procedure. Differences in benefits were noted depending on the age of the patients. The greatest benefits were seen in the less than 1-year-old and 7- to 12-year-old age groups.

Adolescent↗
PubMed1985

Lobar collapse with respiratory syncytial virus pneumonitis.

In a study of 30 children with uncomplicated respiratory syncytial virus (RSV) pneumonias, a high incidence of lobar collapse (8/30-26%) was noted. This involved the right upper lobe in seven patients and the left upper lobe in one patient. It is probably attributable to anatomical predispositions, sloughing of necrotic epithelium, and stimulation of mucus production. Lobar collapse should be considered part of the spectrum of RSV pneumonitis.

Female↗
PubMed1985

Cystic ovarian teratomas: the sonographic appearance of the dermoid plug.

The sonographic and pathological appearance of 13 cystic ovarian teratomas was reviewed. Twelve contained at least one mural nodule (dermoid plug) and one was completely cystic. Altogether there were 15 dermoid plugs, varying in consistency from homogeneous solid tissue to cystic. More than half were associated with hair and/or calcium. The nodules were round, ranged from 1 1/2 to 4 cm, formed an acute angle with the wall of the cyst, and tended to be entirely or predominantly hyperechoic. The authors suggest that most cystic teratomas contain dermoid plugs having a characteristic shape and hyperechoic pattern.

Dermoid Cyst↗
PubMed1984

Scintigraphic detection of acute gastrointestinal bleeding using 99Tcm-DTPA.

Technetium-99m DTPA is a good agent for detecting sites of acute gastrointestinal bleeding due to its rapid clearance by the kidneys and its stability in the bowel achieving a good target to nontarget ratio. It has been successfully tried for a pilot study. Further evaluation is in progress for its sensitivity. In cases where there is a slow rate of bleeding, we are currently evaluating injection of the dose by infusion, slowly over 15 min instead of the rapid i.v. injection.

Duodenal Ulcer↗
PubMed1978

The ampicillin rash as a diagnostic and management problem: case reports and literature review.

Ampicillin is the most commonly prescribed antibiotic in the United States, and causes skin reactions in five to ten percent of patient populations. These reactions are considerably more frequent in patients with a viral illness, infectious mononucleosis, and lymphocytic leukemia. Skin reactions to ampicillin are usually of two types: a maculopapular rash in about two thirds of cases, and urticaria in about one third of cases. There is strong evidence that the maculopapular rash is a benign, nonallergic phenomenon. Patients with the maculopapular ampicillin rash are often incorrectly labeled as allergic to ampicillin/penicillin. Ampicillin can be continued and administered again in the future in these patients, and this kind of skin reaction resolves spontaneously in a few days without sequelae. Skin tests are neither required nor recommended to document the nonallergic basis of the maculopapular ampicillin rash.

Ampicillin↗
PubMed1976

Epidemic.

Explore the source record for details and available documents.

Humans↗