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Biomedical subjects

G Logue

Publications and source records attributed to G Logue.

At least 19 recordsLinked to original sources
PubMed1997

Cortisol pharmacodynamics after methylprednisolone administration in young and elderly males.

Glucocorticoids are commonly prescribed in the elderly on an empiric basis with little consideration for the age-related alterations in pharmacologic response. The objectives of this study were to compare the effect of methylprednisolone on cortisol patterns in elderly and young healthy men, to define the relationship between pharmacokinetic parameters of methylprednisolone and pharmacodynamics of cortisol in the elderly and young men. Seven healthy, elderly males (69-82 years old) and five healthy, young males (24-37 years old) participated in a 24-hour pharmacodynamic trial with randomized assignment to a control period (Phase 1) and a methylprednisolone period (Phase II). Serial blood samples were obtained throughout both study periods. Cortisol measurements included the total area under the concentration-time curve (AUC), return AUC, and suppression ratio. During Phase I, a circadian pattern was noted in both groups. After exposure to methylprednisolone (Phase II), a linear decline in serum concentrations of cortisol was observed in both groups. The return AUC of cortisol (425 +/- 357 ng.hr/mL [elderly] versus 854 +/- 216 ng.mL [young]) and the total AUC 764 +/- 340 ng.h/mL [elderly] versus 1,230 +/- 258 ng.hr/mL [young]) were significantly lower in the older men. In addition, a significant decline in total AUC and nadir concentration of cortisol from Phase I to Phase II was noted within both groups. The suppression ratio was significantly greater in the elderly men (mean, 0.38 versus 0.58 in young), which indicates a greater degree of adrenal suppression after administration of methylprednisolone. Exposure to methylprednisolone, as measured by AUC, was 554 +/- 215 ng.hr/kg (elderly) and 389 +/- 102 ng.hr/kg (young). The greater exposure to methylprednisolone noted in the elderly yielded significant combined correlations for both groups with AUC, return AUC, and suppression ratio of cortisol. A more significant response of cortisol to the exogenous glucocorticoid was apparent in the elderly men. In addition, a slower clearance of methylprednisolone was noted in the elderly group compared with their young counterparts. The effect of reduced clearance of methylprednisolone on the suppression ratio indicates the interrelationship between the disposition of a single dose of an exogenous glucocorticoid and response patterns of cortisol.

Adult↗
PubMed1995

A desperate solution: individual autonomy and the double-blind controlled experiment.

The randomization ingredient in double-blind controlled experiments may be objectionable to patients who, in their desperation, come to such trials seeking a last chance of cure. Minogue et al., who view such a situation as inherently exploitive and undermining of patient autonomy, propose that such "desperate volunteers" instead be enrolled in the active arm, while other patients, less desperate and more committed to medical progress, continue to be randomized. Their view is critiqued as destructive of medical progress, inappropriate in its lack of clinical response to such patients, and fatally flawed by unrealistic notions of autonomy and voluntariness.

Control Groups↗
PubMed1994

Toleration of moral diversity and the conscientious refusal by physicians to withdraw life-sustaining treatment.

The removal of life-sustaining treatment often brings physicians into conflict with patients. Because of their moral beliefs physicians often respond slowly to the request of patients or their families. People in bioethics have been quick to recommend that in cases of conflict the physician should simply sign off the case and "step aside". This is not easily done psychologically or morally. Such a resolution also masks a number of more subtle, quite trouble some problems that conflict with the commitment to toleration and moral diversity that it is intended to support. These conflicts are detailed and evaluated.

Attitude of Health Personnel↗
PubMed1994

Pharmacokinetics of methylprednisolone in elderly and young healthy males.

OBJECTIVE: To characterize and compare the pharmacokinetics of a single intravenous dose of methylprednisolone in elderly and young healthy males. DESIGN: A randomized, parallel pharmacokinetic trial. SETTING: A public university-affiliated hospital. SUBJECTS: Seven healthy, elderly white males (aged 69 to 82 years) and five healthy, young white males (aged 24 to 37 years) who gave informed consent and fulfilled all screening criteria. MEASUREMENTS: Serial blood samples were obtained over a 24-hour study period after intravenous administration of a 10-mg dose of methylprednisolone. Serum methylprednisolone concentrations were determined by high performance liquid chromatography and utilized to determine the pharmacokinetic parameters. RESULTS: Methylprednisolone serum concentrations declined in a linear manner in both groups. However, 4 hours after the dose, the mean serum concentration of methylprednisolone was 50.9 +/- 15.1 ng/mL in the elderly group and 37.6 +/- 7.5 (P = 0.07) ng/mL in the young group. The clearance of methylprednisolone was 237 +/- 62 mL/h/kg, with a volume of distribution of 1.10 +/- 0.07 L/kg, for the elderly group, whereas the young males had a mean drug clearance of 359 +/- 90 mL/h/kg (P < 0.05) and a mean volume of distribution of 1.28 +/- 0.34 L/kg. The half-life of methylprednisolone ranged from 1.90 to 5.40 hours in the elderly group; the range was 1.99 to 3.31 hour (P = 0.016) in the young group. CONCLUSION: A slower methylprednisolone clearance was noted in the elderly group compared with the young counterparts. This pharmacokinetic alteration seen in healthy elderly subjects may contribute to the increased incidence of adverse effects from chronic glucocorticoid therapy that has been observed among elderly patients.

Adult↗
PubMed1992

Functional heredity protein S deficiency with arterial thrombosis.

Protein S is a vitamin K-dependent protein that functions as a regulatory protein to limit clotting. The authors present and discuss the case of a 37-year-old man with a type IIa protein S deficiency. The diagnosis and treatment of a protein S deficiency is also described.

Adult↗
PubMed1981

Human IgG antigranulocyte antibodies: comparison of detection by quantitative antiglobulin consumption and by binding of 125I staph protein A.

The amount of IgG in the serum of patients with suspected immune neutropenia that binds to normal paraformaldehyde-fixed human granulocytes was measured simultaneously by a quantitative antiglobulin consumption assay and by binding of 125I-staphylococcal protein A (SPA). There was a significant linear relationship between the results of these two assays for the sera of 42 different patients. However, SPA binding appeared more sensitive than the quantitative antiglobulin assay for determining IgG antigranulocyte antibodies in serum. In a patient with Felty's syndrome who underwent splenectomy, the results of both assays on sequential serum samples correlated with clinical improvement. Thus, SPA binding appears to be a sensitive and reliable technique for measuring antigranulocyte antibodies, and there is a close correlation between antibody measured by antiglobulin consumption and those detected by SPA binding.

Agranulocytosis↗
PubMed1979

The use of in vitro technics to study drug-induced pancytopenia.

The confirmation of drug-induced marrow aplasia is difficult since rechallenging the patient can lead to serious morbidity. We used marrow-culture technics to challenge in vitro the bone marrow of a patient with marrow aplasia after ingestion of quinidine. There was no clinical or laboratory evidence of quinidine-mediated destruction of erythrocytes, leukocytes or platelets. By contrast, use of quinidine in combination with the patient's serum substantially inhibited in vitro growth of allogeneic marrow granulocytic and erythroid series. Furthermore, use of quinidine in combination with acute-phase serum (but not acute-phase serum alone or quinidine in combination with recovery-phase serum) inhibited growth of the patient's marrow. This observation suggests that both a transient serum factor and quinidine were responsible for the marrow aplasia. These technics could be applied with minimal risk to similar patients and would permit in vitro rechallenge with the suspected drug.

Aged↗
PubMed1979

Cold agglutinin autoimmune hemolytic anemia in nonhematologic malignancies.

Four patients with nonhematologic malignancies had the simultaneous finding of hemolytic anemia due to high-titer cold agglutinins. In each patient, the cold agglutinin had "anti-I" specificity and was of the IgM kappa immunoglobulin class. Although patients with hematologic malignancies not uncommonly have cold agglutinins, the association between these antibodies and nonhematologic malignancies is unusual.

Adolescent↗
PubMed1979

Inappropriate antidiuretic hormone complicating histiocytic lymphoma.

The syndrome of inappropriate antidiuretic hormone (IADH) often causes the hyponatremia that may be seen in patients with malignant disorders. Most physicians correctly associate IADH with small cell carcinoma of the lung. We describe two patients in whom IADH was caused by histiocytic lymphoma. One patient was thought to have small cell carcinoma of the lung on the basis of marrow infiltration and the IADH. When the proper diagnosis was made and therapy instituted, both patients responded, with rapid resolution of their disease and the IADH. The identification of the neoplasm that produces the IADH is important, since histiocytic lymphoma may mimic small cell carcinoma of the lung, yet may be very responsive with newer treatment regimens.

Aged↗
PubMed1978

Treatment of chronic granulocytic leukemia with melphalan.

Thirty-three patients with newly diagnosed chronic granulocytic leukemia (CGL) were treated with melphalan between 1968 and 1976. Within 3 mo of beginning therapy subjective and objective disease parameters improved. Disease control was easily maintained with this agent until hematologic exacerbation occurred. The median duration of disease control was 25.3 mo, and the median duration of survival was 28.6 mo. Serious side effects were not produced. Thus melphalan appears to be another agent that may be used to control the manifestations of CGL prior to hematologic exacerbation.

Adolescent↗
PubMed1976

Felty's syndrome: granulocyte-bound immunoglobulin G and splenectomy.

A quantitative antiglobulin consumption technique was used to measure immunoglobulin G (IgG) present on human granulocytes. Granulocytes from 50 normal subjects had less than 20 X 10(-14) g IgG per cell. Patients with granulocytopenia due to bone-marrow failure, patients with IgG multiple myeloma, patients with splenomegaly, and patients with rheumatoid arthritis without granulocytopenia had granulocyte-bound IgG within the range of normal. Four patients with rheumatoid arthritis, splenomegaly, and severe granulocytopenia (Felty's syndrome) had granulocyte-bound IgG between 30 and 220 X 10(-14) g IgG per cell. One of these patients underwent splenectomy, after which his granulocyte-bound IgG fell to normal. Seven additional patients with Felty's syndrome who had previously undergone splenectomy had normal levels of granulocyte-bound IgG. Thus quantitation of granulocyte-bound IgG appears to be useful in defining patients with immunologically mediated granulocytopenia. Studies of patients with Felty's syndrome who have undergone splenectomy suggest that the spleen may produce this neutrophile-bound immunoglobulin.

Adult↗