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Biomedical subjects

R Davis

Publications and source records attributed to R Davis.

At least 469 records · Page 26Linked to original sources
PubMed1976

The detection and significance of calcifications in the breast: a radiological and pathological study.

The radiological detection of calcification is compared using xeroradiography, non-screen film and a film-screen combination. The "threshold" values of the smallest detectable size of calcification, under simulated clinical conditions, are found to be approximately 100 mum for xeroradiography and 400 mum for both the film techniques in this study. The incidence of calcification seen on the preoperative mammograms of patients with carcinoma of the breast is 48-5 per cent. Further calcification revealed by histological examination raises the overall incidence of calcification in mammary carcinomas to 63 per cent. The incidence on preoperative mammograms in benign breast disease is 20 per cent. The radiological features of calcification occurring in malignant and benign breast lesions are recorded, and no definitive distinguishing features are established. The histological appearance of calcification in malignant and benign breast disease is discussed.

Breast Diseases↗
PubMed1976

Radiation exposure to the patient in xeroradiography.

The paper presents measurements of the radiation exposure required in xeroradiography of the breast and of the extremities. The nature of the radiation hazard and the most appropriate quantity by which to assess it are discussed, and it is shown that for a number of radiological procedures xeroradiographs can be taken for about the same radiation exposure to the patient as that required by conventional film techniques.

Arthrography↗
PubMed1976

Radiation doses to staff in a department of nuclear medicine.

A survey of data concerning radiation protection of staff working in the Nuclear Medicine Department and associated sections of the Physics Department at the Royal Marsden Hospital (Surrey Branch) is given for the period 1972 to 1975 inclusive. Results of routine film monitoring and whole-body counting are presented. Additional film monitors were used to check working areas, finger doses and any discrepancies between doses to the upper and lower trunk of personnel. In general, exposure to staff in the Nuclear Medicine Department is below 220 mrad per person per year, and below 1,000 mrad per person per year in the Radioisotope Dispensary. The dose received by radiographers is primarily due to spending time close to patients. Since about 5,000 intravenous injections of radionuclides are given each year in our department, the resulting finger doses to the staff involved may give rise to concern unless the task is shared.

Body Burden↗
PubMed1976

The problem of discrimination in mammography. Arguments for using a biological test object.

A specimen of breast tissue containing a carcinoma with multiple calcifications was used as a test object and examined by a range of mammographic techniques. The images were compared with a photograph of the actual specimen which was cleared and stained for calcium salts. A quantitative method of evaluating the discriminating ability of each technique is described and used to compare these images. Xeroradiography and Kodak Crystallex film clearly excelled other imaging methods. The value of using a biological test object is discussed.

Breast Neoplasms↗
PubMed1976

Detection of drugs of abuse by radioimmunoassay: a summary of published data and some new information.

We review the status of radioimmunoassays for detection of abused drugs. Individual assays with use of 125I-labeled antigens are all performed in an identical manner and can be completed in 30 min to 1 h. Combined assays for simultaneous detection of two or more such drugs or assays in which a tritium-labeled antigen is used require 1-2 h for completion. All tests can be performed with 0.1 ml or less of specimen. The assays involving 125I reliably detect urinary concentrations of, per liter, 40-100 mug of morphine, 100 mug of barbiturates, methadone, methaqualone, or benzoylecgonine, and 1000 mug of amphetamine. The assay for morphine involving 3H detects 60 mug/liter. Each assay is capable of providing a qualitative and quantitative estimate of the drugs sought. The 125I-labeled antigens have a usable shelf life of at least two to four months after the antigen is iodinated; the tritium assay is stable for six months. The assays can be performed with use of paper discs that have been suspended in urine and then dried, in place of the liquid specimen. The assays appear to be equally applicable to detection of drugs in urine, blood, saliva, and tissues. All of them are done at ambient temperature and can be used equally well for emergency (stat) tests or mass screening. Except for the benzoylecgonine assay, the clinical reliability of these tests has been demonstrated.

Amphetamine↗
PubMed1976

Computerized consultation system for selection of antimicrobial therapy.

Mycin, a computer-based consultation system which provides to physicians antimicrobial therapy recommendations for patients with bacterial infections, is described. The consultation program arrives at therapeutic decisions using a built-in knowledge base as well as patient data entered by the physician. The system is capable of explaining its recommendations and answering questions about its reasoning process. The system's knowledge can be updated and corrected easily by infectious disease experts. At present the system is operational within a research setting; its routine use in a clinical setting will require further evaluation of its reliability and effectiveness.

Anti-Infective Agents↗
PubMed1975

Fetal stress from methadone withdrawal.

A pregnant patient in the midtrimester of pregnancy was begun on a methadone detoxification program. The fetal neurobiologic response was monitored by serial amniotic fluid amines (epinephrine and norepinephrine). The detoxification program showed a marked fetal response of the adrenal gland (E) and sympathetic nervous system (NE) that was blunted when the methadone dose was increased. Detoxification during pregnancy is not recommended unless the fetus can be biochemically monitored.

Adrenal Glands↗
PubMed1975

Surgery of left paraduodenal hernia.

The clinical presentation, embryologic and etiologic factors, and repair of left paraduodenal hernia are presented. A new operative procedure for cure of left paraduodenal hernia is presented that deals effectively with the sac and predisposing arch containing the inferior mesenteric vein without section of the vein. Repair is based upon the embryologically normal anatomy with restoration of the inferior mesenteric vein to its normal retroperitoneal position. This procedure has been successfully utilized in a case in which the paraduodenal hernia of small bowel was encountered concomitantly with a perforated duodenal ulcer.

Adult↗