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Biomedical subjects

C A Sanders

Publications and source records attributed to C A Sanders.

At least 37 records · Page 2Linked to original sources
PubMed1989

Stool diagnosis of giardiasis using a commercially available enzyme immunoassay to detect Giardia-specific antigen 65 (GSA 65).

A commercially available enzyme immunoassay for the diagnosis of giardiasis was evaluated in a clinical trial. The ProSpecT/Giardia diagnostic test (Alexon, Inc., Mountain View, Calif.) was compared with the standard ova and parasite (O&P) microscopic examination. Additionally, several widely used stool fixatives and a commonly used transport medium were assessed for compatibility with the immunoassay. A total of 325 stool specimens were collected and used to evaluate assay performance. Of those, 93 specimens were collected from symptomatic Giardia O&P-positive patients and 232 specimens were randomly collected from patients as part of a routine health screening procedure. All 93 Giardia O&P-positive stool specimens were strongly positive by visual and spectrophotometric examination using the immunoassay. Of the 232 randomly collected specimens, 16 were positive by O&P examination and immunoassay, 6 were negative by O&P examination but positive by immunoassay, and 1 was positive by O&P examination and negative by immunoassay. There was substantial supportive evidence that indicated that the six immunoassay-positive, O&P-negative specimens were true-positives. When these six specimens were accepted as true-positives, the immunoassay detected almost 30% more cases of Giardia infection than did O&P examination. Its sensitivity and specificity were 96 and 100%, respectively, while the sensitivity and specificity of O&P examination were 74 and 100%, respectively. The immunoassay also performed well on specimens treated with 10% neutral Formalin, sodium acetate-Formalin fixative, and Cary-Blair transport medium. However, the test was not compatible with polyvinyl alcohol-treated specimens. Overall, the ProSpecT/Giardia test was a sensitive, specific immunoassay which was easy to run and interpret. It offers a simple solution to traditional difficulties encountered in diagnosing Giardia infection.

Animals↗
PubMed1989

Killing by antimycobacterial agents of AIDS-derived strains of Mycobacterium avium complex inside cells of the mouse macrophage cell line J774.

The murine macrophage continuous cell line J774 was used to measure the ability of antimicrobial agents, either singly or in combination, to kill intracellular Mycobacterium avium complex. All of 14 strains of M. avium complex, isolated from patients with AIDS, grew inside J774 cells during an incubation period of 7 days. The susceptibility of macrophage-ingested M. avium complex to antimicrobial agents was determined by comparing the number of colony-forming units (cfu) of M. avium complex inside untreated macrophages at the time of drug addition with the number of cfu present in macrophages after treatment with drugs for 7 days. Simultaneous experiments were carried out in broth medium without macrophages in order to compare killing of free mycobacteria with killing of macrophage-ingested mycobacteria. Antimicrobial agents (rifampin, rifabutin [Ansamycin], ethambutol, ciprofloxacin, clofazimine, isoniazid, and amikacin) were tested using concentrations that are achievable in the serum of patients. Among drugs known to penetrate macrophages, there was 96.2% agreement in susceptibility test results between the broth experiments and the J774 experiments when single drugs were tested, but only 74% agreement when combinations of drugs were tested. Killing of M. avium complex inside J774 cells by any single drug was uncommon. However, killing in J774 cells occurred against 10 of 11 (91%) strains with the combination of rifabutin + ethambutol + ciprofloxacin and against all of seven strains tested with the combination of rifabutin + ethambutol + amikacin. Interpretive criteria of in vitro susceptibility data need to be developed so that these interpretations correlate with a predictable clinical response in patients.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Stability of penicillins in total parenteral nutrient solution.

The stability of ticarcillin, mezlocillin, and piperacillin in total parenteral nutrient (TPN) solutions at concentrations commonly used in adults was determined. Each antibiotic was added separately to three different amino acids-dextrose TPN solutions in two concentrations: 10 and 20 mg/mL. Amino acids concentration ranged from 25 g/L to 50 g/L. Dextrose concentration ranged from 100 g/L to 350 g/L. Solutions were assayed for antibiotic concentration immediately after mixing (time 0) and at 4, 8, 24, and 48 hours by high-performance liquid chromatography. The effect of the added penicillins on the stability of amino acids and other TPN additives was not investigated. Mezlocillin and piperacillin 10 and 20 mg/mL exhibited stability in TPN solution at 24 hours. Ticarcillin was stable for 24 hours at a concentration of 10 mg/mL, but at 20 mg/mL it was unstable at all times tested. The three antibiotics demonstrated the same characteristic stability in all three TPN solutions, suggesting that the concentrations of dextrose and amino acids did not affect stability. Ticarcillin, mezlocillin, and piperacillin are stable for 24 hours in the TPN solutions studied.

Chromatography, High Pressure Liquid↗
PubMed1985

Academic-industrial relationships.

In conclusion, it is obvious that the delivery system for medical care is changing much faster than anticipated. Technology is the agent in this process and economics is both the driving and the limiting force: driving because it is the impetus to change the sites of medical practice, limiting because of the constrained number of dollars to allocate to technology acquisition and operation. As we move into the future, it cannot be emphasized too strongly that hospitals and industry should be complementary in this process. To do so successfully requires an understanding of the mission each seeks to pursue and of what each can do for the other.

Ambulatory Care↗
PubMed1979

Reflections on psychiatry in the general-hospital setting.

For psychiatry to be successfully integrated into the general hospital, the psychiatrist must function within the medical model, and his mode of practice must be consistent with general-hospital caretaking. The author discusses the positive effects of consultative and liaison psychiatry linkages in the general-hospital setting as well as the problems of financing; there are inequities of reimbursement for consultation and a lack of payment for liaison services. He makes several suggestions about the education of the psychiatrist; it should not be geared exclusively toward the psychiatrist's role as a primary caretaker. Medical schools should introduce students to the discipline of psychiatry and its interrelationships with other disciplines. Teaching hospitals should train the psychiatrist in the medical model. The author feels that the future of general psychiatry does not lie in primary care per se but in its being an identified specialty closely allied to super-specialists and to primary caretakers alike.

Boston↗
PubMed1978

Taming the technological tiger.

The proliferation of technology in hospitals has reached a point where care must be observed both in the introduction of new technology and in the use of existing technology. To achieve this goal, a behavioral modification on the part of hospitals, physicians, and the public must be brought about. Such a modification is best accomplished by the promotion of incentives within the system rather than by the imposition of stringent regulations that relegate provider and regulator to adversary positions.

Costs and Cost Analysis↗
PubMed1974

Incomplete relaxation between beats after myocardial hypoxia and ischemia.

Recovery from hypoxia has been shown to prolong cardiac muscle contraction, particularly the relaxation phase. The present studies were designed to examine whether incomplete relaxation between beats can result from this prolongation of contraction and relaxation in isolated muscle after hypoxia and in the canine heart after both hypoxia and acute ischemia. The relationship between heart rate and the extent of incomplete relaxation is emphasized in view of the known enhancement of the velocity of contraction caused by increasing heart rate. The extent of incomplete relaxation during 10-s periods of pacing at increasing rates was examined before and after hypoxia in isometric cat right ventricular papillary muscle (12-120 beats/min) and in the canine isovolumic left ventricle (120-180 beats/min). Incomplete relaxation was quantified by measuring the difference between the lowest diastolic tension or pressure during pacing and the true resting tension or pressure determined by interruption of pacing at each rate. In eight cat papillary muscles (29 degrees C), there was significantly greater incomplete relaxation 5 min after hypoxia at rates of 96 and 120 beats/min (P < 0.02 vs. before hypoxia). In seven canine isovolumic left ventricles, recovery from hypoxia and higher heart rates also resulted in incomplete relaxation. Incomplete relaxation before hypoxia at a rate of 180 beats/min was 0.8+/-0.5 cm H(2)O and at 5 min of recovery from hypoxia was 12.6+/-3.5 cm H(2)O (P < 0.01). 12 hearts were subjected to a 1.5-3-min period of acute ischemia and fibrillation. There was significant incomplete relaxation at a rate of 140 beats/min for 5 min after defibrillation and reperfusion. These data indicate that incomplete relaxation is an important determinant of diastolic hemodynamics during recovery from ischemia or hypoxia. The extent of incomplete relaxation appears to be a function of the rate of normalization of the velocity of relaxation and tension development after ischemia or hypoxia, the heart rate, and the magnitude of developed tension or pressure.

Animals↗