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Biomedical subjects

C B Cook

Publications and source records attributed to C B Cook.

34 records · Page 2Linked to original sources
PubMed1980

False negative hepatitis B surface antigen detection in dialysis patients due to excess surface antigen: postzone phenomenon.

Renal dialysis patients are well known to have a high incidence of hepatitis B carrier state. In studying a group of 63 long-term dialysis patients, 10 were found to be positive for hepatitis B surface antigen by radioimmunoassay (RIA). Surprisingly, however, only three of these RIA positive patients were positive by counter immunoelectrophoresis (CIEP). The discrepancy could not be accounted for by the difference in sensitivity of the two methods. The cause for the negative reactions by CIEP in seven patients was found to be the marked excess surface antigen in these sera which produced false negative results by the postzone phenomenon. After dilution all seven sera were positive by CIEP, requiring a dilution up to 1/20 to produce a positive result. Also, all seven sera were positive by the less sensitive Ouchterlony double diffusion.

Adult↗
PubMed1978

Acidometric agar plate method for ampicillin susceptibility testing of Haemophilus influenzae.

The need for an accurate and rapid method of testing ampicillin susceptibility of Haemophilus influenzae, especially strains isolated from patients with meningitis and septicemia, is indisputable. Various methods have been employed for this purpose. Each has advantages and disadvantages. This report describes a modification of the capillary acidometric procedure in which an agar plate is substituted for a tube. All beta-lactamase results obtained by this modified technique correlated with minimal inhibitory concentrations determined in liquid media and the chromogenic cephalosporin substrate method. This modified acidometric agar procedure is a simple, inexpensive, accurate, and rapid way to determine H. influenzae susceptibility to ampicillin.

Ampicillin↗
PubMed1978

Endocytic mechanisms of the digestive cells of Hydra viridis. 1. Morphological aspects.

The endocytic mechanisms of the digestive cells of Hydra viridis were examined by transmission electron microscopy. Algae which form a stable intracellular symbiosis are phagocytosed by uncoated plasmalemma, as are large (greater than 0.5 micron) food particles. Discoidal coated vesicles apparently effect the endocytosis of smaller particles, including macromolecules. Competition experiments indicate that the uptake of algae and larger food particles utilize similar endocytic membrane.

Animals↗
PubMed1975

Single image pericardial effusion evaluation with technetium compounds.

Three cases of suspected pericardial effusion were evaluated with rapid, noninvasive procedure, combined use of macroaggregated albumin technetium 99m and human serum albumin technetium 99m to produce a single radiography showing the heart, liver, and lung perfusion simultaneously. This technic confirmed the diagnosis of pericardial effusion in two cases and ruled out this possibility in the third case.

Adult↗
PubMedDate not supplied

A comparison of two commercially available in vitro chemosensitivity assays.

In vitro chemosensitivity assays (IVCAs) are expensive laboratory tests utilized to assist oncologists in the selection of chemotherapeutic regimens. Their utility is disputed; yet, these assays continue to be requested because of the importance of the information they can provide and their scientifically logical approach. Therefore, we compared the results of two assays offered to clinicians at our hospital; the extreme drug resistance assay performed by Oncotech (OT) and the fluorescent cytoprint assays performed by Analytical Biosystems (AB). The two techniques used and the expression of assay results by the two companies are discussed. Twenty neoplasms, all at least 3 cm in diameter and predominantly of breast and ovarian origin, were compared. OT performed 74 drug assays on 17 tumors, while AB performed 194 assays on the corresponding neoplasms; 3 neoplasms were insufficient for comparison. Evaluation of the results revealed apparent disagreement on at least 44 drug assays with complete disagreement on at least 2 of the drugs tested in 12 of 17 cases. In conclusion, based on available information, comparisons between IVCAs show great variation in results; prospective studies are needed to evaluate commercially available assays for correlation with clinical outcome, and results should be expressed so comparisons can be readily made. Though utility may be limited to tumors resistant to standard therapy, cost and benefit to the patient will ultimately determine the fate of these tests.

Antineoplastic Agents↗