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Biomedical subjects

J R Singer

Publications and source records attributed to J R Singer.

14 recordsLinked to original sources
PubMed1995

Subclavian hemodialysis catheter infections: a prospective, randomized trial of an attachable silver-impregnated cuff for prevention of catheter-related infections.

OBJECTIVE: To determine if an attachable silver-impregnated cuff is effective in reducing subclavian hemodialysis catheter-related infections. DESIGN: Prospective, randomized, nonblinded study. SETTING: Community teaching hospital. PATIENTS: One hundred one acute and chronic renal failure patients requiring subclavian venipuncture and catheterization. After randomization, 47 patients underwent subclavian catheterization with a silver-impregnated cuff (Ag-CC), and 54 patients had routine catheter (RC) placements. MEASUREMENTS: Multiple presumed predictor variables for catheter-related infections, exit site infection rate, bacteremia rates, and semiquantitative cultures of all catheters.

Analysis of Variance↗
PubMed1985

Ruptured aneurysm in pregnancy.

Within the last ten years, twenty pregnant women with ruptured intracranial aneurysms were managed at Los Angeles County-University of Southern California Medical Center. Difficulties encountered in the care of these patients will be illustrated with case studies. In two patients, failure to diagnose subarachnoid hemorrhage delayed management. In another patient, cerebral vasospasm complicated the course. Selection of appropriate diagnostic tests, timing of surgery, importance of fetal monitoring, and method of delivery will be discussed.

Adolescent↗
PubMed1984

Idiopathic acute interstitial nephritis: characterization of the infiltrating cells in the renal interstitium as T helper lymphocytes.

A previously healthy 39-year-old man presented with acute renal failure. There was no history of exposure to drugs nor was there any infection. Renal biopsy revealed interstitial nephritis with extensive acute degenerative changes in the tubules and extensive interstitial infiltration with mononuclear cells and no eosinophils. Monoclonal antibody staining studies identified the cells in the renal interstitium to be a helper/inducer subset of T lymphocytes. We suggest that a delayed hypersensitivity mechanism played a pathogenetic role in this patient's idiopathic acute interstitial nephritis.

Acute Kidney Injury↗
PubMed1970

Blood velocity measurements in intact subjects.

Venous blood velocities in intact human forearms can be measured by the use of nuclear magnetic resonance techniques. In essence, two separated coils are placed over the vein, and the arm is held in a magnetic field. Radio-frequency energy in one coil "flips" over the protons in the blood stream, and the second coil detects the arrival of the "flipped" protons. Human blood in vivo and in vitro has a nominal nuclear magnetic resonance relaxation time of 0.4 second.

Blood Flow Velocity↗
PubMedDate not supplied

Tomographic imaging with nuclear magnetic resonance.

A technique is described for obtaining tomographic images of hydrogen distribution in animals using nuclear magnetic resonance (NMR). Resonant frequency is proportional to magnetic field strength, so that spatial resolution is achieved by frequency selection and magnetic field shaping. The results of scanning a phantom and two rats are presented.

Animals↗
PubMedDate not supplied

Low-frequency white noise generators for biomedical systems.

There is a need for electronic noise sources for investigation of biological and medical research equipment. Such sources need to provide a "white noise" output with a frequency spectrum flat from one to one hundred Hertz. The present paper describes two designs of such sources. The spectra are measured and compared. One course is the reverse-biased junction of a transistor base-emitter junction operating in the avalanche mode. The second source is a MOS IC pseudo-random digital signal. In both cases, the spectra are presented. The choice between the two sources depends upon the application. For most applications, either source is shown to be satisfactory.

Electronics, Medical↗
PubMedDate not supplied

Experimental transmission of Chlamydia psittaci to turkeys from wild birds.

Wild birds were inoculated with Chlamydia psittaci to determine species that could be potential hosts and vectors in transmitting the agent to domestic turkeys. Infection occurred in turkeys exposed to starlings (Sturnus vulgaris), common grackles (Quiscalus quiscula), brown-headed cowbirds (Molothrus ater), and Inca doves (Cardafella inca). Mourning doves (Zenaidura macroura) shed the agent sparingly, but turkeys exposed to them did not become infected, These findings and knowledge of the habits of these various species are discussed. It was concluded that the Inca dove should be considered a potential source of turkey chlamydiosis in Texas. The species studied and other species not studied should be included in serologic surveys and surveillance studies attempting isolation of chlamydiae.

Animal Population Groups↗