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Biomedical subjects

L Whitfield

Publications and source records attributed to L Whitfield.

7 recordsLinked to original sources
PubMed1995

A case study of nursing case management in a rural hospital.

This article describes the process of implementing a New England model of case management in a rural hospital and the modifications necessary in adapting an urban model to a rural setting. Nursing case management at this institution has been associated with a decrease in the length of stay by 1.7 days at an estimated cost savings of $65,932 for the 16-month study period. Case management has also been instrumental in improving quality of care through a program of continuous quality improvement and in redesigning the RN role. The vision for the future is to extend the nurse case manager role outside the hospital walls to the community in a collaborative plan that would bill nursing services through physicians' offices.

Cost-Benefit Analysis↗
PubMed1993

Phase I pharmacokinetic study of DUP-937, a new anthrapyrazole.

DUP-937 is a new anthrapyrazole intercalator that inhibits DNA synthesis. A phase I trial was conducted in which DUP-937 was given in an intravenous bolus weekly for 3 weeks. Cycles were repeated every 5 weeks. Twenty men and 13 women with median ECOG performance status of 1 completed 74 cycles. The starting dose was 0.55 mg/m2/week and doses were escalated to 16 mg/m2/week. Non-hematological toxicity was generally mild or moderate and consisted mainly of gastro-intestinal effects, fatigue, alopecia and local reactions. Grade 3 neutropenia was first documented at 7.36 mg/m2 and became more common at higher dose levels. Three of four patients had > or = grade 3 neutropenia at the 16 mg/m2 dose level. Thrombocytopenia was minimal. The dose-limiting toxicity was neutropenia and the maximum tolerated dose was 16 mg/m2 weekly for 3 weeks. Mean area under the curve (AUC) values increased with dose. Linear pharmacokinetics were observed as total body clearance (CLtb), half-life (t1/2) and volume of distribution (Vss) did not change with increasing doses. One partial remission in a patient with prostate carcinoma was documented.

Adult↗
PubMed1992

Phase I and pharmacokinetic study of the novel platinum analogue CI-973 on a 5-daily dose schedule.

CI-973, a platinum(II) derivative with a 2-methyl-1,4-butanediamine carrier ligand, has activity in cisplatin-resistant tumor models in vitro and in vivo. In a Phase I pharmacokinetic study, 31 patients were treated with CI-973 (24 to 50 mg/m2/day for 5 days; 28-day cycles) given i.v. over 30 min without routine antiemetic prophylaxis or hydration. Of the 29 patients evaluable for maximum tolerated dose determination, most had a performance status of 0 or 1, and most had received prior chemotherapy. Neutropenia was dose limiting at 40 and 50 mg/m2/day. Recovery from neutropenia was generally rapid with nadir counts and recovery usually occurring by Days 15 and 22, respectively. Drug-associated thrombocytopenia was uncommon and never severe, even in patients with Grade 4 neutropenia. Anemia was common, but did not appear dose related. Drug-related nausea and vomiting and changes in renal function were relatively infrequent and mild. No clinically evident ototoxicity was reported, although changes in audiograms were noted in several patients. CI-973 concentrations were measured in plasma ultrafiltrate and urine by high-pressure liquid chromatography. The harmonic mean terminal half-life was 2.0 h. The mean CI-973 renal and nonrenal clearance values were 42.3 and 37.4 ml/min/m2, respectively. The mean recovery of CI-973 in urine was 53% of the administered dose. The mean ratio of CI-973 renal clearance to creatinine clearance was 0.92. Total clearance correlated with creatinine clearance (r2 = 0.63). A relationship between toxicity, expressed as the percentage of reduction in absolute granulocyte count, and area under the CI-973 plasma concentration-time curve was found in a subgroup of "good-risk" patients. This relationship, described well by a sigmoidal Emax pharmacodynamic model, did not hold for patients with extensive prior therapy or poor performance status. A model for toxicity prediction based on dose and creatinine clearance has been derived and will be validated in future studies. The recommended Phase II dose of CI-973 is 30 mg/m2/day for 5 days.

Adolescent↗
PubMed1989

Lack of dose proportional pharmacokinetics for CI-937, an anthrapyrazole DNA intercalator, in mice.

The time course of CI-937, an anthrapyrazole DNA intercalator, was studied in plasma of mice after single intravenous doses of 1.2, 8, 12, and 15 mg/kg (1/10 the LD10, 2/3 the LD10, LD10, and LD50). CI-937 concentrations in plasma were determined by a sensitive radioimmunoassay capable of quantifying 0.1 ng/ml. Area under the plasma concentration-time curve increased less than proportionally to dose. Time-averaged plasma clearance was dose-dependent, increasing from 31.1 to 63.6 ml/min/kg over the 1.2 to 12 mg/kg dose range. Terminal half-life in plasma ranged from 11 to 25 days. Fraction plasma protein bound was 69 to 76% from 10 to 10,000 ng/ml, which suggests the nonlinear behavior was not due to saturable protein binding. Potential mechanisms include autoinduction of metabolism and dose-dependent reabsorption from the gastrointestinal tract or kidneys.

Animals↗
PubMed1980

Dopaminergic control of plasma catecholamine and aldosterone responses to acute stimuli in normal man.

This study examines the influence of dopamine on catecholamine and aldosterone secretion in normotensive individuals. The responses of plasma aldosterone (PA), norepinephrine (NE), and PRA to upright posture and isometric handgrip were studied in five normal males on a constant 50-meq Na intake before and after 4 days of administration of the dopamine agonist, bromergocriptine (BEC; 2.5 mg three times a day). In addition, the PA responses to graded angiotensin II and ACTH infusions were examined before and during BEC. Supine PA and PRA were not altered by BEC, but basal NE was reduced significantly (P < 0.01) from 204 +/- 29 to 98 +/- 12 pg/ml after BEC. There was an accompanying significant reduction in upright mean arterial pressure during BEC administration. The PA and NE during upright posture and isometric handgrip were significantly suppressed by BEC, but PRA responses were unaltered. BEC produced a significiant (P < 0.025) suppression of the PA response to graded angiotensin II infusions but did not alter the PA response to graded ACTH. Our findings indicate that in normal man there is a pronounced inhibitory effect of dopaminergic pathways on catecholamine scretion and regulation of upright mean arterial pressure. Results of the posture study would suggest that dopamine-mediated PA alterations occur independently of changes in the levels of PRA. The finding that BEC suppressed PA responses to angiotensin II and posture but not to ACTH would imply that dopamine selectively exerts its effect or adrenal angiotensin II-mediated aldosterone secretion.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Developing a quality management strategy.

A collaborative strategy between a college of nursing and a specialist nursing service was devised using outcomes driven by the ENB Higher Award. The successful implementation of this strategy has shown that the expectations of increased clinical-based innovation, resulting from this new approach to practitioner development, are achievable.

Humans↗