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Biomedical subjects

S D Nightingale

Publications and source records attributed to S D Nightingale.

At least 19 recordsLinked to original sources
PubMed1992

Sustained-release ganciclovir therapy for treatment of cytomegalovirus retinitis. Use of an intravitreal device.

A surgically implantable device for sustained intravitreal release of ganciclovir has been developed. The device delivers ganciclovir intraocularly over approximately 4 to 5 months. Eight patients with acquired immunodeficiency syndrome (AIDS) and associated cytomegalovirus (CMV) retinitis were recruited as part of a phase 1 study. Thirteen eyes with active CMV retinitis underwent surgical implantation of the ganciclovir device. All eyes showed resolution of the CMV retinitis; none showed progression. Visual acuity remained unchanged in three eyes, improved in six eyes, and decreased in four eyes. Surgical complications included mild vitreous hemorrhage, astigmatism, and suprachoroidal placement of the device. Retinal detachment occurred in three eyes as the retinitis resolved. This new intraocular drug delivery system offers many advantages compared with intravenous therapy or repeated intravitreal ganciclovir injections for the management of CMV retinitis in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Intravitreal ganciclovir pharmacokinetics in rabbits and man.

Cytomegalovirus (CMV) retinitis occurs in immunocompromised patients and can be treated by repeated intravenous or intravitreal injections of ganciclovir (GCV) or foscarnet. Due to toxicity and complications these modalities are not ideal. The development of alternative administration routes is hindered by a lack of pharmacokinetic data. Devices giving pseudo zero order release of GCV were implanted intravitreally first in rabbits and then in patients with AIDS associated CMV retinitis as part of a Phase I clinical trial. Steady state intravitreal GCV levels were obtained immediately after death and the elimination rate constants were calculated assuming first order pharmacokinetics. Normalizing for retinal surface area, distribution volume and anatomic volume, the retinal elimination rate constants were calculated. These were found to be 0.017 cm-2hr-1 in rabbits and 0.015 cm-2hr-1 in man. This indicates that the rabbit eye is a good model for studying intravitreal pharmacokinetics of ganciclovir and suggests a common elimination mechanism which may be trans-retinal.

Animals↗
PubMed1992

Monoclonal antibody to Pneumocystis carinii. Comparison with silver stain in bronchial lavage specimens.

Monoclonal 3F6 anti-Pneumocystis carinii antibody (MAB-3F6) was used to stain cell blocks from 164 bronchial lavage specimens from patients with the acquired immune deficiency syndrome (AIDS) and AIDS-related complex and compared with slides stained with Grocott's modification of the Gomori methenamine silver stain. Pneumocystis organisms were present in 83 of 164 cases using MAB-3F6 stain, whereas Grocott's modified silver stain demonstrated Pneumocystis organisms in 48. MAB-3F6 demonstrated Pneumocystis organisms in 38 cases with negative silver stains, whereas silver stain identified Pneumocystis organisms in only three MAB-3F6-negative cases. Of 70 patients with clinical Pneumocystis pneumonia at the time of the specimen was obtained, 59 had MAB-3F6-positive specimens, whereas 39 had organisms detected using Grocott's modified silver stain. Of 37 patients without clinically apparent Pneumocystis pneumonia any time in their course, 4 had abundant organisms and 33 had negative stains with MAB-3F6. MAB-3F6 detected Pneumocystis organisms in 22 of 31 cases of Pneumocystis pneumonia that had no organisms identified using Grocott's silver stain (X2 = 5.76, P = 0.016). MAB-3F6 immunochemical staining is a more sensitive method than Grocott's modified silver stain to detect Pneumocystis organisms.

Antibodies, Monoclonal↗
PubMed1992

Incidence of Mycobacterium avium-intracellulare complex bacteremia in human immunodeficiency virus-positive patients.

The product-limit incidence of Mycobacterium avium-intracellulare complex (MAC) bacteremia in 1006 human immunodeficiency virus (HIV)-positive patients followed at one institution over a 3-year period from the day of AIDS diagnosis with monthly lysis-centrifugation blood cultures was 21% +/- 2% SE at 1 year and 43% +/- 3% at 2 years. The product-limit incidence of MAC bacteremia at 1 year after the patients' first CD4 cell count was related to both the CD4 cell count and to whether they had an AIDS diagnosis (both P less than .0001) but not to age, sex, or race. This incidence was 39% +/- 6% for CD4 cell counts of less than 10/mm3, 30% +/- 5% for 10-19/mm3, 20% +/- 4% for 20-39/mm3, 15% +/- 4% for 40-59/mm3, 8% +/- 3% for 60-99/mm3, and 3% +/- 1% for 100-199/mm3. MAC may eventually infect most if not all HIV-positive patients who do not die from another HIV-related event.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Primary prophylaxis with fluconazole against systemic fungal infections in HIV-positive patients.

OBJECTIVE: To investigate the efficacy of fluconazole prophylaxis against systemic fungal infections in HIV-positive patients. DESIGN: Open label treatment compared with historical controls. SETTING: Patients were seen at the Parkland Memorial Hospital HIV Clinic, Dallas, Texas, USA between 1 March 1990 and 28 February 1991. PATIENTS, PARTICIPANTS: Three hundred and thirty-seven historical controls were followed for 157 patient-years, and 329 fluconazole-treated patients for 145 patient-years. INTERVENTIONS: Fluconazole (100 mg daily) was administered to all patients with CD4 lymphocyte counts less than 68 x 10(6)/l seen at our HIV clinic after 1 March 1990. MAIN OUTCOME MEASURES: Lysis-centrifugation blood cultures were recorded monthly for all patients during both study periods. RESULTS: Twenty infections (16 cryptococcosis, four histoplasmosis) occurred in 337 historical reference control patients (product-limit 1-year incidence, 7.5 +/- 2.0/year). Four infections (one cryptococcosis, three histoplasmosis) occurred in the treated patient group (product-limit 1-year incidence, 1.8 +/- 0.9/year). CONCLUSIONS: Fluconazole warrants further evaluation for prophylaxis against systemic fungal infections in HIV-positive patients.

Adult↗
PubMed1990

Disseminated histoplasmosis in patients with AIDS.

Disseminated histoplasmosis was diagnosed in 36 (4%) of 980 patients with AIDS seen at Parkland Memorial Hospital in Dallas, Texas before September 30, 1989. Diagnostic sensitivity of blood culture plus examination of peripheral smear was 88%; sensitivity of bone marrow aspiration and blood culture was 80%. Median CD4 lymphocyte count at diagnosis was 33/cu mm. Median actuarial survival from the date histoplasmosis was diagnosed was 188 days. Thirteen (36%) of the 36 patients died before adequate antifungal therapy could be administered, while 13 survived long enough to receive 1,500 mg of amphotericin B; actuarial survival of the latter group from the date 1,500 mg of amphotericin B had been infused was 47% at 1 year. The substantial early mortality of AIDS-associated disseminated histoplasmosis and the modestly encouraging survival of those who were diagnosed in time to receive adequate therapy raise the issues of surveillance, prophylaxis, and empiric therapy for this infection in selected HIV-positive patients.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Risk preference and decision making in critical care situations.

Physician attitudes towards risk may influence their behavior in critical care situations. To explore this hypothesis, physicians' responses to a questionnaire about risk were compared to their preferences towards "intubation" or "current therapy without intubation" for a hypothetical patient with end-stage lung disease, and to the length of time they performed cardiopulmonary resuscitation before they declared their efforts unsuccessful. When the choices on the questionnaire were framed in terms of loss, choice of the risky alternative was associated with greater preference for "intubation," and with longer duration of resuscitation efforts (both p less than .005). At least part of the variation in physician attitudes and practices towards the care of the critically or terminally ill is associated with measurable psychologic differences among individual physicians.

Adult↗
PubMed1978

Glucose-induced hyperkalemia with normal aldosterone levels. Studies in a patient with diabetes mellitus.

A diabetic patient exhibited glucose-induced hyperkalemia despite normal plasma and urinary aldosterone levels. The patient received no diuretics, was not acidotic, and had a creatinine clearance of 39 ml/min. Insulin or pharmacologic doses of desoxycorticosterone acetate eliminated the glucose-induced hyperkalemia. Normal aldosterone levels may be insufficient to protect certain diabetic patients from glucose-induced hyperkalemia.

Aged↗
PubMed1975

Pharmacokinetic characteristics of doxycycline accumulation in normal and severely diseased kidneys.

Intrarenal concentrations of doxycycline were measured in 48 normal canine kidneys during wide variations in urine pH and the systemic state of hydration of the experimental animals. The results were compared with the renal parenchymal levels achieved in 10 severely diseased human kidneys. Although the state of hydration, the urine pH, and renal disease all significantly influenced the urinary concentrations and rate of renal clearance of doxycycline, there was no detectable difference between concentrations in normal renal tissue and those in severely diseased kidneys. This result is in contradistinction of the findings for previously evaluated antibiotics. The levels of doxycycline measured in renal tissue averaged twice the concentration in serum without notable difference among levels in renal cortex, medulla, and papilla. Prospective clinical trials will be necessary for identification of any solid correlation between the remarkable characteristics of accumulation of doxycycline in diseased renal parenchymal tissue and the clinical, therapeutic importance of such an observation.

Animals↗
PubMedDate not supplied

Risk preference and laboratory test selection.

The risk preferences in situations of potential gain, and of potential loss, expressed by 67 physicians were correlated with the numbers of laboratory tests they selected after review of identical copies of two outpatient charts. Physicians who chose a 50/50 gamble of losing ten or no years of life expectancy over an equivalent certain loss of five years selected twice as many tests as those who chose the loss (p less than 0.025). Risk preferences may provide some insight into why some physicians order more laboratory tests than do others.

Decision Theory↗
PubMedDate not supplied

Risk preference and laboratory use.

One hundred thirty-seven physicians were asked to choose between a certain loss of five years of life expectancy and a 50/50 gamble of losing either ten years or zero years of life expectancy. These choices were presented as hypothetical options for a patient with cancer. The 46 who chose the certain loss ordered 23% fewer laboratory tests/patient visit in our General Medicine Clinic over an eight-week period than those who chose the gamble (p less than 0.05). This risk preference was further stratified by sequentially offering five, four, three, two, and one years of certain loss against the same 50/50 gamble of ten or zero years of loss; greater preference for the gamble correlated with greater laboratory use (p less than 0.002). To exclude physician knowledge or case mix as a cause of this result, this risk preference was correlated with total score, and with the cost of tests ordered in patient management problems, of 49 physician on the American Board of Internal Medicine Certifying Examination. Cost of tests ordered was 23% less for the 17 who chose the certain loss (p less than 0.001); total score did not vary with risk preferences. There was no association between risk preference in the face of gain and laboratory use, and none between an individual's risk preferences in the face of gain and in the face of loss. The cognitive processes that determine risk preference in the face of loss, whatever they may be, appear to have a substantial influence on physician test-ordering behavior.

Clinical Laboratory Techniques↗
PubMedDate not supplied

Psychological androgyny and preference for intubation in a hypothetical case of end-stage lung disease.

Psychological androgyny theory (PAT) was employed as a model of the interpersonal (social) and task activities required of physicians for care of their patients. According to PAT, individuals with a large repertoire of task and social skills ("androgynous" individuals) should be optimally adaptable to contingencies reflecting varying combinations of task and social challenges. The authors examined the relationship between androgyny and preference for intubation on a patient management problem involving end-stage lung disease for 67 general internists and internal medicine housestaff from two hospitals. Results revealed a negative relationship between androgyny and preference for intubation, suggesting that androgynous and nonandrogynous physicians respond differently to complex and difficult decision-making tasks. Indirect evidence is offered to suggest that this response reflects a general tendency to utilize fewer health care resources. Discussion focuses on the need to improve the precision of measurement of these latent constructs.

Extraversion, Psychological↗
PubMedDate not supplied

Psychological androgyny and preference in loss-framed gambles of medical students: possible implications for resource utilization.

Physician decisions concerning allocation of health care resources to patients are highly variable and poorly understood. Psychological androgyny theory (PAT) has been employed as a model of the interpersonal and task activities required of physicians for care of their patients. Several studies have successfully predicted physician resource utilization using measures derived from PAT. Using a sample of 97 first-year medical students, the authors explored the relationship between PAT and risk preference in loss-framed gambles in order to elucidate the process whereby variables derived from PAT predict resource utilization. As hypothesized, students selecting the certain loss had significantly higher mean androgyny scores than did students selecting uncertainty. Research involving these constructs is integrated in the context of a theoretical "causal model," which highlights issues deserving of future research.

Choice Behavior↗