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Biomedical subjects

C A Robinson

Publications and source records attributed to C A Robinson.

At least 73 records · Page 4Linked to original sources
PubMed1987

Mineral content of bone: measurement by energy subtraction digital chest radiography.

Several methods are presently available for measuring the mineral content of bone. Those in widespread use include dual-photon absorptiometry and quantitative CT. The feasibility of using dual-energy digital chest radiography for determination of the mineral content of posterior ribs on digital chest images was studied by using a prototype unit. The results showed a significant difference in the mineral density of the posterior ribs of control subjects and those of patients who had osteoporosis (251.1 +/- 36 mg Ca2+/cm2 of rib vs 158.8 +/- 48 mg Ca2+/cm2, p less than or equal to .01) and a close correlation with values obtained by dual-photon absorptiometry of the lumbar spine (r = .77). The results suggest that this technique can provide an accurate assessment of the presence or absence of osteoporosis.

Adult↗
PubMed1987

Roadblocks to family centered care when a chronically ill child is hospitalized.

Little has been written about how repeated hospitalizations affect family life when the context is chronic rather than acute illness. This article presents findings from a qualitative study designed to explore parents' views when their chronically ill children were hospitalized. These findings address the problems arising when the family's frame of reference is oriented toward their experience with long-term illness and the frame of reference of the professional health care provider in the hospital is oriented toward acute disease. It is suggested that unacknowledged discrepancies in viewpoints may cause the relationships between family members and professional health care providers to become adversarial, a situation which negatively affects both the effectiveness of care and perceived satisfaction with care.

Attitude of Health Personnel↗
PubMed1987

Accuracy of three methods for predicting concentrations of free phenytoin.

Predictions of free (unbound) serum phenytoin concentration by three methods were compared with results obtained by the Abbott TDx Free Phenytoin ultrafiltration and fluorescence-polarization immunoassay technique. Data were obtained for hospitalized adults who had been receiving phenytoin for at least five days and were free of renal or hepatic disease. Total phenytoin concentration was determined, and free phenytoin concentration was measured in ultrafiltrate at 25 degrees C. For each patient, measured concentrations of total phenytoin and albumin were used to predict free phenytoin concentrations by the Gugler method, the Sheiner-Tozer nomogram, and the Sheiner-Tozer equation. Mean measured percentages of free phenytoin were 17.79%, 12.13%, and 8.73%, respectively, for patients with albumin concentrations of less than 2 g/dL (n = 5), 2-3 g/dL (n = 18), and greater than 3 g/dL (n = 26). There was a strong correlation between actual and predicted free phenytoin concentrations for each of the methods, but all methods were found to lack precision. All methods also exhibited bias, as demonstrated by overprediction of the free concentration; however, none of the methods exhibited bias when the difference between the in vitro temperature of 25 degrees C and the in vivo temperature of 37 degrees C was considered. Because of their poor precision, the three methods evaluated in this study are not recommended for predicting free phenytoin concentration.

Adult↗
PubMed1986

Sjögren's syndrome. Proposed criteria for classification.

The term "Sjögren's syndrome" (SS) is frequently used to describe the occurrence of keratoconjunctivis sicca and xerostomia in association with an autoimmune disorder. However, well-defined criteria for the classification of SS have not been established, and this diagnosis is being applied to a wide spectrum of conditions, ranging from clear "autoimmune" disease in some patients, to sicca complaints without evidence of a systemic immune process in elderly patients. Here, we review the clinical and laboratory features of patients referred for evaluation of sicca symptoms. In particular, we emphasize the need for care in choosing the site for minor salivary gland biopsy, and we describe the histologic features that aid in the evaluation of these biopsy specimens. In an attempt to identify a population of patients whose conditions might have a common etiopathogenesis and, thus, a common treatment program, we propose the following criteria for a diagnosis of SS: 1) objective evidence of keratoconjunctivis sicca, as documented by rose bengal or fluorescein dye staining; 2) objective evidence of diminished salivary gland flow; 3) minor salivary gland biopsy, obtained through normal mucosa, with the specimen containing at least 4 evaluable salivary gland lobules, and having an average of at least 2 foci/4 mm2; 4) evidence of a systemic autoimmune process, as manifested by the presence of autoantibodies, such as rheumatoid factor and/or antinuclear antibody. The diagnosis of "definite SS" would be made when all 4 criteria are met; the diagnosis of "possible SS" would be made when 3 criteria are present. Specific exclusions for this diagnosis are preexisting lymphoma, graft-versus-host disease, sarcoidosis, and acquired immunodeficiency disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1986

Calcification in pulmonary nodules: detection with dual-energy digital radiography.

The authors undertook a clinical study to determine the accuracy of dual-energy digital radiography in revealing nodule calcification because calcification in a pulmonary nodule almost excludes the possibility of malignancy. Over a 6-month period, 61 patients with pulmonary nodules (less than or equal to 3 cm) or masses (greater than 3 cm) were examined on a prototype scanned projection unit using a dual-energy detector. In 49 of 61 patients, nodules were noncalcified, and in 12, they were calcified. In 57 patients, the benignancy or malignancy of nodules was established beyond reasonable doubt by pathologic confirmation in 38 and by strong inference in 19 (four patients with noncalcified solitary pulmonary nodules either refused further investigation or surgery or their follow-up was too short to permit exclusion of malignancy). Dual-energy radiography was found to be highly accurate in assessing the presence or absence of calcification in pulmonary nodules and thus in determining their benignancy or possible malignancy.

Adult↗
PubMed1986

Basis for defective responses of rheumatoid arthritis synovial fluid lymphocytes to anti-CD3 (T3) antibodies.

Synovial fluid mononuclear cells (SFMC) from patients with active rheumatoid arthritis characteristically respond poorly to mitogens. In this study, mitogenic antibodies reactive with the CD3(T3) antigen on human T lymphocytes were used to analyze the basis for the deficiency. OKT3-induced proliferation and release of interleukin 1 (IL-1) and interleukin 2 (IL-2) from SFMC were depressed in all patients. Purified IL-1 or recombinant IL-2 restored proliferative responses in SFMC and increased IL-2 receptor density. Exogenous IL-1 also enhanced IL-2 release. Fractionation of SFMC supernatants on phosphocellulose columns revealed the presence of IL-1 and a potent IL-1 inhibitor. The monocyte-derived IL-1 inhibitor blocked IL-1-dependent responses of normal peripheral blood lymphocytes to OKT3, but had no effect on IL-2-dependent events. These results suggest that IL-1 inhibitor(s) in SFMC impair(s) OKT3-induced mitogenesis by interfering with the effects of IL-1 on T lymphocytes. The net result is deficient IL-2 secretion, IL-2 receptor expression, and impaired cellular proliferation. This novel inhibitory circuit provides a rational explanation for the diminished function of synovial fluid T lymphocytes in rheumatoid arthritis patients.

Adult↗
PubMed1986

Potential value of digital radiography. Preliminary observations on the use of dual-energy subtraction in the evaluation of pulmonary nodules.

The radiographic demonstration of calcification in a solitary pulmonary nodule renders the possibility of malignancy extremely unlikely, although rare exceptions have been reported. Conventional roentgenograms and tomograms sometimes provide inconclusive evidence although CT can be highly accurate in both identifying and quantifying calcium content. An alternative method is dual-energy subtraction utilizing scanned projection digital radiography. Forty-one patients with solitary (occasionally multiple) pulmonary nodules were examined with the technique, employing second-generation fan-beam equipment: 28 nodules or masses were noncalcified and 13 calcified. Of the former, 20 were pathologically proved, 16 being malignant and 4 benign (2 granulomas, 2 bronchiectasis); in 3 of the remaining 8, a presumptive diagnosis was reasonably certain (1 granuloma, 2 metastases), while in 5 the diagnosis was not made. In 8 of the 13 calcified lesions, the diagnosis can reasonably be regarded as confirmed as granulomas; 5 are being followed up with that presumptive diagnosis.

Adult↗
PubMed1985

ANAs in systemic rheumatic disease. Diagnostic significance.

Development of the lupus erythematosus (LE) cell test some 40 years ago opened up the world of ANAs to the clinician. Armed with the availability of a battery of tests for ANAs of different specificities, the modern clinician has the tools for increased diagnostic sensitivity in rheumatic disease and more accurate differentiation of systemic rheumatic diseases that sometimes present with confusing overlapping clinical features. The tests, however, should not be used indiscriminately, and their interpretation should always be done critically and in the context of the clinical presentation.

Antibodies, Antinuclear↗
PubMed1985

IgG antibodies to the histone complex H2A-H2B characterize procainamide-induced lupus.

Patients treated with procainamide and other drugs commonly develop antinuclear antibodies and occasionally symptoms of lupus erythematosus. However, the pathological events which lead to clinical symptoms in some patients but only abnormal serology in others have not been established. The present study examines the incidence, amount, immunoglobulin class, and antigen-binding specificity of anti-histone and anti-denatured DNA (anti-dDNA) antibodies in three groups of patients. These comprised a prospective study of patients treated with procainamide, patients with clinical drug-induced lupus symptoms, and a group undergoing therapy for many years without any symptoms. Procainamide elicited IgG and IgM anti-dDNA antibodies concordantly. Anti-histone IgM antibodies also appeared de novo during this period but IgG anti-histone antibodies were detected less frequently. Asymptomatic patients tended to have an antibody profile consisting of highly elevated anti-dDNA, IgM antibodies reactive with all histones and IgG antibodies specific for only one or two histone classes. In contrast symptomatic patients usually had little anti-dDNA or antibodies to individual histones but had pronounced IgG antibodies to the histone complex H2A-H2B. This unique antibody was characteristics of procainamide-induced lupus and was not detected in patients whose disease was induced by hydralazine. Anti-(H2A-H2B) decreased after procainamide was discontinued, concomitant with subsidence of symptoms. The finding that autoantibodies elicited by procainamide in patients with lupus symptoms have a characteristic immunoglobulin class and specificity may be of pathogenic significance and suggests that patients susceptible to procainamide-induced lupus have a unique immune response. In addition, this information could be of diagnostic value in predicting which procainamide-treated patients will develop overt symptoms of lupus.

Adult↗
PubMed1984

Abnormal lactate dehydrogenase isoenzyme pattern in a critically ill patient.

We have described a patient who had an abnormal isoenzyme of lactate dehydrogenase in both serum and tissue. The presence of LD6 is indicative of a poor prognosis. Some of the biochemical characteristics of the isoenzyme are (1) LD6 is not an artifact, (2) it contains an M subunit but not an H subunit, and (3) it is not an immunoglobulin complex. We believe LD6 may arise during episodes of severe shock as lysosomes rupture and is either a previously sequestered lysosomal LD or is a lysosomal modification of LD5.

Acidosis↗
PubMed1984

Strengthening family 'interference'.

This paper examines the phenomenon of family 'interference' in the health care of a sick member from a new angle. The 'interfering' behaviours are located within the context of the family's evolving relationships with health care providers. The authors argue that the behaviours are an understandable product of the family's disillusionment and dissatisfaction with their health care relationships. As such, these interfering behaviours represent the family's most productive means of positively influencing their sick member's experience with illness. In addition, they set the stage for negotiation to take place between the family and health care providers which leads to mutually satisfying care. When interference is appreciated within the context of health care relationships, it becomes obvious that some of our traditional nursing responses are counterproductive. This paper offers suggestions for making interference work, as well as theoretical questions to the nursing practitioner.

Attitude of Health Personnel↗